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Ok guys, help me out here.. Finally got a chance to start diagnosing this since I want to take it to the Maggie Valley show in May...
90 350 TBI burb. Wouldn't stay running and dies when stopping. It was throwing codes and I replaced the IAC and EGR, both bad. Codes are gone.
Still dies in gear and will eventually die in idle. Pulled the Booster line off and the dying in park became sparadic. Replaced the booster.
Now it idles around 675rpm and dies when it goes into gear. Scanning it with WinALDL and the sensor data and raw data look ok to me. (it does have and exhaust leak)
Pull the IAC connector and it runs fine and doesn't stall or die in gear. IAC is good, removed from R10 to test it.
TPS data looks good also.
Anyone care to throw out something obvious that I am now overlooking since I been working on it too long? Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project
Edited by: roundedline at: 3/31/07 2:22 pm
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Getting down to basics, the ECM controls the IAC to keep the correct rpms at idle. With no load, the setting should be around 20, of 256. As a load to the engine takes place such as power steering, alternator, AC, or whatever, the rpms would fall. But, the ECM steps up the valve to keep a constant rpm.
If you unplug the IAC, the engine does fine. Try turning on the AC or turning the steering all the way one way or the other, turn headlights on, perhaps all of these while idling and see if RPM’s go down. It should if IAC is not hooked up. With IAC hooked up, the rpms will remain constant, in theory.
If you know the IAC valve is fine, something is telling the ECM to bring the IAC to a lower setting, therefore the engine stalls.
Why would the ECM be trying to set the IAC too low?? Is there an RPM sensor or other means that is giving the ECM false info?? (does ECM read the coil or distributor to get rpms?) Or you have a load at idle (AC on, power steering pump under pressure etc) and the ECM is not setting the IAC to a higher number. ECM may be at fault. On my wife's cherokee, the crankshaft position sensor failed and caused the engine to shut off--starving of gas due to the ecm telling the gas to shut off and killing the ignition.
IAC setting is displayed thru serial data. You can play with the engine load at idle (AC, alt) and see if IAC setting changes.
I have heard of too high rpms. Cruse Control parts can fail and lodge in the throttle cable, dirty throttle body etc..
A way you can check the crankshaft position sensor is when it shuts off again, keep key on (don't turn key to off position). Turn the key to start the ignition again. If it doesnt fire, or show spark, the sensor tells the ecm to keep the ignition off. If after turning the key all the way off and waiting about 15 seconds and trying to start the engine again--basically resetting the cps, and it starts, well the cps may be bad. But this doesnt answer the fact that when the IAC is unplugged, engine runs fine.
You mentioned you have an exhaust leak...is that before the O2 sensor? If so, that would be allowing fresh O2 into the reading of the sensor. That in turn would create a richer mixture because the O2 sensor thinks more gas is required to burn the hydrocarbons. SgtDel
aka "Andy"
www.delbridge.net
1979 Big 10 383 stroker
1991 Blu 'Burb 3/4 ton 4x4
Edited by: SgtDel
at: 3/31/07 7:32 pm
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Well if it dies only when you put it in gear the most likely cause is a vacuum leak. What are your IAC counts at idle? Did you check the TBI base gasket? Is your TPS set at .55V ?
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Sorry I had enough of it yesterday that I just dropped it, since it was blocking my garage and I didn't want it dead there.
TPS is showing .57V at idle and the IAC count is averaging about 68 (ranging 63-70) which means leak to me. Base gasket looked fine.
It eventually dies in Park after if fight to keep it running and looses. I have checked what I believe is everything for a vacuum leak, I must just be overlooking something.... Just looking for fresh ideas. Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project
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Mass Airflow Sensor? (Air intake tube) While it's running you can take a screwdriver and rap it with the handle to see if it affects the idle- might even stall it out. If it does, that's the culprit.
Don St.Clair
Culleoka Tn
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There is no MAF on his truck it has speed density. I would spray the base of the TBI with some carb clean and see what happens. If that checks out ok pop the oil cap off and see if the engine speed changes and your IAC counts change.
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Guess I should have stated that I basically sprayed the whole top of the motor down with carb cleaner while it was running on Saturday, no change in idle, no noticable leaks, which is why I got frustrated....
I passed this by my buddy at dinner tonight and he said it could be the intake gasket, I will check the oil cap tomorrow. Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project
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Just tossing this in but I have had better luck with starting fluid than carb clean on stuborn or hard to find vacume leaks.
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If you it checks out ok then install a fuel pressure gauge and check your fuel pressure.
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Well, it still dies after it warms up, but I can put it in gear and it won't die when stopping anymore. But it will die when going in reverse from a stop. Here is the IAC sensor data from the time I cranked it in gear to the time it died, I can give you the whole dump (and raw data) if you want...
SENSOR:IAC
64
64
64
64
59
51
46
43
42
41
38
36
34
32
31
31
29
28
28
28
28
26
26
25
24
24
24
24
24
24
24
26
26
26
26
25
25
25
24
24
24
24
24
24
24
24
25
25
25
25
25
24
23
23
Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project
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It should be able to hold a strong idle around 30 counts. What is your MAP voltage before it stalls? Is it setting any DTC's? Does it only stall once you put it in gear? If so how does it idle before you put it in gear and what is your IAC counts after you let it run for at least 60 seconds? The higher the count the more air it is bypassing the throttle plate to allow more air (increasing engine speed) 0 would indicate IAC all the way home 140 or higher is wide open. This can help you identify what's happening. Once you put a load on the engine at idle speed if it just stalls I would check the MAP voltage.
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This is the sensor data from the time it is cranked to dying in gear:
Time        IAC        Temp        MAP
0.4        64        150.2        29.9
1.6        64        150.2        32.5
2.8        64        150.2        31.4
4        64        150.2        31.8
5.1        59        150.2        31
6.3        51        150.2        31.8
7.5        46        150.2        32.5
8.7        43        149.4        33.2
9.9        42        149.4        32.5
11.1        41        149.4        32.5
12.3        38        149.4        34.3
13.5        36        149.4        33.2
14.6        34        149.4        35.1
15.8        32        149.4        32.9
17        31        149.4        34
18.2        31        149.4        34.7
19.4        29        149.4        34
20.6        28        149.4        35.4
21.8        28        148.7        34
23        28        148.7        35.1
24.1        28        148.7        32.1
25.3        26        148.7        36.6
26.6        26        148.7        34.3
27.7        25        148.7        35.1
28.9        24        148.7        34
30.1        24        148.7        35.1
31.3        24        148.7        34
32.5        24        148.7        34.7
33.6        24        148.7        33.2
34.9        24        148.7        34.7
36.1        24        148.7        34.3
37.2        26        148.7        35.8
38.4        26        148.7        33.6
39.6        26        148.7        35.1
40.8        26        148.7        33.6
42        25        148.7        34.7
43.2        25        148.7        35.1
44.4        25        148.7        34.7
45.6        24        148.7        34.3
46.7        24        148.7        34.7
47.9        24        148.7        34.3
49.1        24        148.7        34.3
50.3        24        148.7        35.1
51.5        24        148.7        33.6
52.7        24        147.9        34.3
53.9        24        147.9        33.6
55.1        25        148.7        35.1
56.2        25        147.9        33.2
57.4        25        147.9        34.3
58.6        25        147.9        35.1
59.8        25        147.9        33.2
61        24        147.9        33.2
62.2        23        147.9        33.2
62.9        23        147.9        33.2
RPM        TPS        O2
850        0.7        0.495
825        0.7        0.495
875        0.7        0.495
850        0.7        0.495
800        0.7        0.495
775        0.7        0.491
725        0.7        0.491
700        0.7        0.473
700        0.7        0.477
700        0.7        0.473
675        0.7        0.469
675        0.7        0.486
625        0.7        0.46
650        0.7        0.486
650        0.7        0.469
625        0.7        0.469
625        0.7        0.486
600        0.7        0.455
625        0.7        0.477
600        0.7        0.464
675        0.7        0.486
575        0.7        0.473
650        0.7        0.473
625        0.7        0.469
625        0.7        0.477
575        0.7        0.464
625        0.7        0.486
600        0.7        0.473
625        0.7        0.482
600        0.7        0.477
600        0.7        0.486
575        0.7        0.473
625        0.7        0.482
600        0.7        0.477
625        0.7        0.486
575        0.7        0.495
575        0.7        0.491
600        0.7        0.495
600        0.7        0.495
575        0.7        0.491
600        0.7        0.486
600        0.7        0.495
550        0.7        0.486
575        0.7        0.495
600        0.7        0.491
625        0.7        0.499
625        0.7        0.504
600        0.7        0.508
625        0.7        0.508
550        0.7        0.504
600        0.7        0.508
625        0.7        0.513
600        0.7        0.504
600        0.7        0.504
Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project
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No DTC's. It dies after about 60 sec in gear, and it will stall going into gear. Before it dies in gear the rpm drops and then it fights to keep it stable then loses.
IAC is at 23 when it is slowly dying. (no load applied). Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project
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OK just check your fuel pressure - if ok
Reset the IAC - Key off for 10 sec start the engine for 5 sec, key off for 10 sec again. Then unplug the IAC and start the engine. - Has anyone messed with the idle stop screw? Set the TPS to .55V If it's still stalling pull off the TBI - it probably sucked in the gasket between the IAC passage and primary's.
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Sorry, just getting back on this. It was pooring down rain, then wife had her pins removed and now it is freezing (40's in Alabama)
Today:
Fuel pressure before the filter is a consistent 13lbs. Set the TPS to .55V instead of .57. and did a reset on IAC. I haven't had a chance to drive it yet, but temperature has changed now from 70's on the second to 40's today. I am trying to get it up to operating temps and see if it will die once warmed up. Plan to stop is and start it back up...
Right now it is running fine as I type this. Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project
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Ok, it is up to 120D temp, not close to operating, but...
It dies going into gear.
I plan to retighten the intake bolts and pull the TBI gasket to see what is up.
BTW, MAP is at 1.1V when it dies going into gear, if it matters. Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project
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Ok, I dug in today and pulled the TBI off to check the gasket, it was fine. Then I started checking the base, flipped it over and the PCV port was blocked on the bottom. AH HA!!
then I check the port and it was completely stopped up.
So, I cleaned the whole lower portion of the unit checked all the ports and put it back on. So far so good, I drove it for 15 minutes without dying. Now I plan to drive it regularly and see what else will show up.
I am hoping to get it running dependably to make it to the All Chevy/GMC Nats in Maggie Valley, NC.
p210.ezboard.com/f7387che...D=40.topic
Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project
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Glad you found the problem. Hopefully that was it.
That Maggie Valley show is the same weekend as the Richmond Nextel Race....gonna work pit road again--look for me on TV. I made it on TV during the Nat'l Anthem lined up w/ the teams on pit road before the race last September.
I went through the Maggie Valley a few years back while on a trip through the Great Smoky Mountains---beautiful place. Even saw a bear down there.
www.delbridge.net/smoky.html
SgtDel
aka "Andy"
www.delbridge.net
1979 Big 10 383 stroker
1991 Blu 'Burb 3/4 ton 4x4
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Let us know how it holds up.
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well after moving my focus and getting back to this, now it only dies in gear. Yippie.... Haven't checked anything yet, just drove it to see if it was still gone...
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Have you set the EST base timing yet? try pinching off the return line and see if it still dies...
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Hi, I was referred to this site (by stovebolt.com) for this very same problem. Did you get it? And if what did it finally end up being? thanks.
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No I haven't had time to trouble shoot it lately. Base timing has been set BTW, but I haven't tested closing off the return line.
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Timing was set, and clamping off the return as best I could on Saturday yeilded no different results.
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I forget where we were at with this thing and don't have time to reread everything right this moment but pull the vacuum line off of the EGR valve and leave it off to eliminate that the valve isn't pulling slighlty open. Also what's your fuel integrator and block learn?
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Sorry, little one has me scrambling for time.
Conditions as of today.
No codes
New IAC, EGR, TPS and basically the whole bottom of the TBI rebuilt
No vacuum leaks
TPS = .55V
IAC count = 25ish
MAP = 30's
Fuel pressure is 13lbs steady.
Base timing set
Clamping the return does nothing.
Once you crank it and it runs for say 3 minutes, drop it in gear (any gear) and it dies.
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Did you unhook the EGR? What about Fuel integrator and block learn? It sounds like the EGR is openeing.
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I didn't get to it last night. I was just updating the post so you would remember where we were.
Previously if I unhooked the IAC it will stay running, but that was a few posts back. Haven't tried that recently. Will check the rest tonight.
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Unhooking the EGR didn't change any thing. (it was recently replaced in the beginning before this post was submitted.)
BLM is 134.
Not sure how Fuel Integrator is referenced on what I have... I have attached screenshots of WinALDL..
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Which trans do you have? Your TCC solenoid isn't sticking on is it? Try unplugging the TCC solenoid and drive it around for a bit and see if it keeps happening. You don't have the connectors criss crossed at the TBI do you? Also check with a timing light pointed at the bottom of your injectors and look at the spray pattern of your injectors. The strobe light will allow you to visually see the injector spray patter, just use an advance timing light so you can adjust the strobe. Hook it up to any wire.
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700R4, I honestly haven't though about the TCC... But is has been dying in park, so I kinda ruled it out.
Spray pattern is the one first thing I checked when it was throwing codes and had to replace some sensors and it was good, but that was a while back, I will check it again...
This thing has be baffled!
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Ok so it just fizzles out? If you tried to keep it running you can though and it fires right back up right? You've made sure it's maintaing fuel pressure when it dies right?
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Yep, and it isn't consistent dying in Park. I let it run one day for 15 minutes, put it in Reverse sputter....
Another day, you let it run and it ran for about 3 minutes and then fizzled off.
Yesterday when I scanned it again, it ran fine for about 10 minutes, put it in drive and it died, (everytime) after about 3 tries going into gear it started died once in park.
If I catch it, it will stay running. If I drive it and slow down and give it some gas, it will stay running. If I drive normal (to me) I consistently have to pat the gas to keep it running, if I drive it slow it can catch it everytime.
I KNOW it is going to be something I am not thinking of...
Last time I checked the fuel pressure it sat steady at 13 while it was running. It is hooked before the filter, so I need assistance in checking the pressure going into gear (and with a baby that isn't easy) because the line isn't long enough on the gauge to reach inside the truck. I will see if I can con a friend one day this week. I would assume if I have good pressure when running in park Drive wouldn't upset it, but....
I do know the fuel sender is bad, so I may pull it and replace the pump anyway. The only think I can think of that would cause this is a bad regulator or pump....
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Have you checked the fuel pump relay? Also does it do it when it's cold or only when it warms up? If it only does it when it warms up try forcing it into open loop and see if it still dies. You can force open loop or field service mode and see if it still stalls to help determine if in fact it is an engine management problem or if it's electrical or fuel pressure related. Did you make sure the injector connectors weren't criss crossed from L to R?
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Ok just started it up and put in R immediately. I starts to stall (bad) but it recovers (I haven't check this before). Apparently it will recover when cold. Forced it to open loop by jumping the ALDL AB conncetor and it still stalls...
I have hear the fuel pump relay under the hood when I switch power...
Injectors aren't crossed.
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I have hear the fuel pump relay under the hood when I switch power...
??? say that again? lol Ok so you can rule out O2 since it happens in open loop. unplug your ECT and see if it does it. If it still does it unplug your TPS and see if it does it. What you are trying to determine here again is if it's a sensor input malfunction. Also have you checked your grounds and connections at the ECM?
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ok I will start pulling sensors.
I know if I pulled the IAC in the past it stayed running, but has a high idle....
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When I pull the CTS out of the manifold it won't crank..
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What? your engine coolant temp disconnected the starter will not crank? It's not related to the cranking circuit of the ignition switch. something is definitely wrong there. Check all of your connections from the battery to the engine block, the back of the pass side cylinder head and at the intake manifold for good tight grounds. If you plug back in your ECT sensor it cranks again? ???
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No, not crank ;D It won't start up. Engine turns over, no fire...
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hmmm - I would suggest checking those grounds anyway. Have you tested your map sensor? High vacuum you should see around 1.25V and increase as vacuum decreases. If it responds slowly -replace it. This is your main engine load sensor and if it happens cold your ECM is primarily looking at Map/Dist Ref/TPS and ECT. You know now it's related to one of these circuits, you said the TPS is definitely good and set correctly. I am going to say Map or ECT if not check the ECM
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I will swap the MAP out of my DD and see what happens and go from there...
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I think I found it!!! If I am right it is exactly what I said, something stupid that I missed. Test driving now, details coming....
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I hope you found the problem, Chris. altho- I hate to see this thread coming to an end. It's been a good read..
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Well, it wasn't the cause of the problem, but the vacuum section of the cruise control has a line that ran behind the distributor which I didn't see and it had a hole in it. After plugging it off at the source and cranking it stayed running when going into gear cold. Drove it about 1 mile and then it started acting like it was running out of gas. Kept it running while driving and threw code 22 and 44 after a wide open romp.
I cleared the codes and plan to check the TPS and O2....
I did replace the battery to fix my motorcycle and put in a new window switch on my wifes car so I don't feel Too bad....
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check the TPS circuit by back probing it with the key on engine off. Stick a pin in cavity A and with your Meter hooked in parallel to GND you should see zero volts and have continuity to ground. Cavity C you should have 5volt reference and cavity B should see with the throttle closed about .5V. Slowly sweep the throttle open and the voltage signal should rise progressively. No spikes or opens. If it checks out ok wiggle test the harness and check your pin tension.
If it's detecting a lean condition from the o2 it's probably a result of the way it's running since you've indicated it does this when it's cold in open loop. I would say if the TPS ckt checks out ok then you have a lean condition and your fuel pressure may be dropping. If fuel pressure isn't dropping I would recheck your TBI and gasket. If that's ok then try another ECM.
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Testing yeilded good continuity and 0 volts. C was .501V B was .55v and moved consistently up to 3.92...
Jumping B to C with sensor unplugged yeilded a code 21 while running. Jumping A to C yeilds 5V. Continuity to the TPS to through the harness is good.
I need assistance to check the Fuel pressure, but I think I can elminiate the TPS. So it is either the ECM or the Fuel Pressure.. Yippie.... I am thinking it is the ECM....
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Just got the fuel pressure gauge hooked up. It is at 12lbs steady. On the low side but it doesn't waiver a bit going into gear...
I guess I will get an ECM....
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Did the ECM Fix it ?????????
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I know you've checked the timing, so it's probably not a bad timing chain if the timing is holding steady. Could there possibly be a loose wire, corroded, or bad connection at the throttle body causing an intermittent spray pattern?
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Welp, new ECM did nothing... Same problem, dies when going into gear...
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" C was .501V "
Do you mean 5.01V?
Ok here's what you should do next. You said you replaced the IAC valve correct? I would test the IAC circuit - you can buy an IAC tester dirt cheap or make one really easy. The other option is to test the continuity of the IAC circuit back to the ECM. If it checks out ok I would pull your TBI back off. Check and clean the IAC passages - blow them out with compresed air and try another IAC valve - there are 2 different TBI base gaskets also make sure you use the right one.
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Also you are absolutely positive your EGR is not hung open a little bit right? Did you pull the oil cap off while it's running to see if it changes engine speed?
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Yeah, 5.0 ... it was late
As of midnight last night, this is what I know.
IAC = good. I am tested it on my DD and drove it for weeks
MAP = good. Same thing tested on the DD.
EGR = good. Tested on DD. Plus replaced it originally because of codes, codes gone.
TPS = good. Circuit tested, range tested, all good.
ECM = good. Switching yeilded the same symptoms.
removing EGR from equation, changes nothing. If you pull it up while running the truck dies.
removing oil cap, changes nothing.
Fuel pressure is steady at all times at 12lbs
The whole lower portion of the TBI has been throuroughly cleaned out. Short of upper gaskets, injectors and regulator, it is basically rebuilt.
TBI base gasket is good.
The ONLY thing that keeps if from dying is disconnecting the IAC from the system as mentioned in post #1, 27 and 36...
So how do I make a cheap IAC Tester?
I will recheck everything again and if it is different, I will post back the results.
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When the air conditioning is turned on, you should be able to see the iac motor moving its pintle outward when you look down into the throttle body.
http://www.wellsmfgcorp.com/pdf/Counterpoint4_1.pdf
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AC is not operational on the truck... It is unplugged.
Continuity on the IAC wires are good through the harness.
Opening oil cap does nothing, EGR is tight, disconnecting = nothing.
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disconnecting what = nothing?
Do you have another TBI you can throw on there?
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Disconnecting the EGR...
I have one that needs complete rebuilding, and the one on my DD.
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Well if you haven't missed anything that we've gone over I would try throwing the other TBI on there.
When you checked your fuel pressure did you T in and remove the fuel filter? You should eliminate the filter and make sure there is no change.
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I don't think I have missed anything. I am going to compile a checklist from this post and mark them off one by one again for good measure. I planned to rebuild the spare later, I get no better time than now.
The fuel pressure gauge is mounted before the filter, with the filter left intact. The filter is less than 3 weeks old as the last time I checked the pressure I replaced the filter.
You still didn't indicate how to make a simple IAC checker...
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Ahh sorry if you have an old IAC motor you'll need the butt end of it. I'll post the recipe tomorrow I have to scan it.
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Did you get the scan Vile?
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F!! I totally forgot! Oops I'm sorry I left it in one of my binders at work. I'll email myself a reminder to scan it tomorrow.
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Here ya go
(http://i6.photobucket.com/albums/y228/Sabaka454/iactester.jpg)
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Hope I still have the broken one. I am in the process of rebuilding the TBI now....
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After starting on the spare TBI I decided to pull the one off the burb and rebuild it instead. You think that the broken spring inside the regulator may be the contributing problem..
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Didn't you swap on a known good one already? What are you doing replacing the injectors and regulator?
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One have one known good one and it is on my Daily Driver. Can't afford to switch it.
I am not replacing the injectors, I am rebuilding the TBI. The Burb has 380K miles on it....
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Anyone know where I can get the fuel pressure regulator spring from? GM doesn't have it seperate, or at least I haven't found it....
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Any auto part store should be able to get you it http://www.autozone.com/R,APP1238631/vehicleId,1034401/initialAction,partProductDetail/store,5152/partType,01150/shopping/partProductDetail.htm
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Vile, your link doesn't work. Care to post the Part number?
I have went to 2 Autozones, 2 O'Riellys, 2 Advanced Auto Parts, 2 NAPAs and 2 dealerships. None have located a PN or any reference to a way to get the spring. O'Riellys will sell me a reman TBI for $280 + core, but all I need is the stupid spring.
GM can get me the injector "pod" assembly with the regulator, but it is over $200.
I am probably either going to get a reman (don't want to) or hit the salvage yards unless I can come up with a PN for the spring so I can get this running again. I KNOW someone has it how else can they rebuild them....
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Gp-Sorensen / Fuel Pressure Regulator Kit
for a 1989 Chevrolet Truck V1500 1/2ton Sub 4WD
About this product:
Part Number: 800-243
Weight: 0.07 lbs.
Warranty: 1 YR
Note: Repair kit
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GM lists it as part of the cover
The pressure regulator is a diaphragm-operated relief valve with system operating pressure on one side and and atmospheric pressure on the other side. The function of the regulator is to maintain a constant pressure to the injectors at all times, by controlling the flow in the return line by means of a calibrated bypass.
NOTE: The pressure regulator on this unit is serviced as part of the fuel meter cover and should not be disassembled.
Fuel Pressure Regulator 17112399
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Gp-Sorensen / Fuel Pressure Regulator Kit
for a 1989 Chevrolet Truck V1500 1/2ton Sub 4WD
About this product:
Part Number: 800-243
Weight: 0.07 lbs.
Warranty: 1 YR
Note: Repair kit
NEGATIVE, that doesn't come with the spring, it is only the diaphram. GM does list it at the cover, and it is around $200 and it does have the regulator and spring and diaphram with it. Question I am debating over is, do I buy a reman for $280 or a cover for $200 to get a $5 spring....
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Well after some serious searching today I found a company that has a spring that is for 12-20psi for $5.
http://www.top-downsolutions.com/product_info.php?products_id=39
I guess I will be modding the regulator to be adjustable now :D
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I guess I didn'trealize all you needed was the spring. What happened to yours?
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I guess you missed that part of the post. When I pulled the spare TBI apart (to rebuilld it) its spring had the top broken off. So I figured the one on there now works so I pulled it off. When I got to the regulator, the spring was broken in 3 pieces. No one sells the spring, but Top Down does sell an aftermarket spring that will give it 12-20psi, I just had to modify the cup so I could lower the pressure down to 12/13... Just finished that a couple minutes ago.
Hopefully Thursday the spring will be there and I can put the back together.
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Springs are here! I am putting this together now....
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Put it on today everything on the TBI is new (TPS, IAC, Injectors, FPR diaphram)
I rebuilt it all yesterday and put it on and one of the injectors was sparaticly not firing. It did run better and didn't die going into gear, but after I drove it and came to a stop in D it started struggling to stay running, this is when I went back and discovered the sparatic misfire of the injector.
Today I put all new injectors on it and it won't stay running at all. It runs for about 1 minute and dies. I am about to put a scanner on it now....
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You should try putting on your good Throttle body and see what happens
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The good one is on a 305, but I am at the end of my rope now. I guess I am going to swap it.....
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Ok, I swapped it out and it won't run longer than 4 seconds with the one off my DD.
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You got to be missing something ! :-\
You have been working on this for quite a while, Have you went back and started from scratch ? After all the swaping see if any thing has changed in the testing.
(Taken from other post)
IAC counts at idle,
TBI base gasket?
Is your TPS set at .55V ?
, pop the oil cap off and see if the engine speed changes and your IAC counts change,
check your fuel pressure,
IAC sensor data,
Reset the IAC,
Set the TPS to .55V,
Wow ! That was just from the first page.
What was it they used to KILL THE GRIMLIN'S ?? ???
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Agreed - you're missing something simple. It's dying out- you've been focusing on the TBI -you've eliminated that and your fuel pressure. Your ECM and sensor inputs all look good. I'm willing to bet at this point you have an ignition system problem.
Check the resistance of the distributor pick up coil. Typically around 800 ohms. Check it cold and check it hot.
Pull the cap off and check the carbon button.
Check the ignition coil - poor some water on it while it's running and see what happens.
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I agree, right before swapping I was talking to Toolmaster on the phone and indicated it can only be ignition left. I hope I can get to it today. I couldn't do anything yesterday. After I pulled the TBI off my DD, it tore the intake gasket and have to steal it from the Burb. I have to pick one of those up before I can move forward.
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Try resetting the iac again?
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Well I got pissed.. After checking the coil pickup (810 ohms), I said to heck with it, went and got a new cap, rotor and coil. Cap coil contact spring was broken, replace it and the rotor, nothing. Replaced the coil, nothing changed. The coil was the original GM one, so I yanked it.
When I pulled the cap/rotor, the insides of the distributor was rusty. I am thinking I will replace it next. I took a video of it from when I cranked it to when it just dies...
http://www.73-87chevytrucks.com/temp/TBI_Burb.ASF (use Media Player)
Try resetting the iac again?
Tried that....
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Anyone got a recommendation on a distributor? I am looking at MSD or Accel, but opinions are welcome.
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Just rebuild yours it's wicked easy. Get a new pickup coil and module. Drive the pin out of the drive gear. If you look at the drive gear it has a dot on one side. That dot faces the same direction as the rotor on the pole piece. Take out the pole piece and replace the pick up coil. I usually wire wheel the pole piece and lube it with some engine oil but not too much.
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have you tried to replace the ignition module with a known good one? I've had similar symptoms with vehicles I'v had in the past that a new ignition module cured.
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also I can't remember but did you say you checked the fuel pump relay?
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Just rebuild yours it's wicked easy. Get a new pickup coil and module. Drive the pin out of the drive gear. If you look at the drive gear it has a dot on one side. That dot faces the same direction as the rotor on the pole piece. Take out the pole piece and replace the pick up coil. I usually wire wheel the pole piece and lube it with some engine oil but not too much.
yeah, I know, but I really don't want to, it is an option if I get into the mood to work on it again, figured this would be a good time to upgrade. I may do that this weekend if I don't break down and get a new one...
have you tried to replace the ignition module with a known good one? I've had similar symptoms with vehicles I'v had in the past that a new ignition module cured.
My only knowm good one is in my DD, and I am definitely not pulling it apart. With a new distributor, I would eliminate all issues with the distributor in one swing.
also I can't remember but did you say you checked the fuel pump relay?
Yep, checked it. It is getting plenty of fuel. It does now have a nice occasional miss to it now.
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The reason I say that is the relay can overheat. Take a jumper wire to the fuel pump test lead and bring it B+. that bypasses the relay and runs current directly to the pump. See if it still dies with the jumper wire on there.
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;D I heard it through the grape vine !!! ;D Chris is driving the Burb ????
Could it BE !!!! He has killed the gremlins !
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Hmmm, that would be me, so you really heard from the grape right? :D
I just drove it all over my neighborhood and stopped at every stop sign. Stayed running the whole time. I am getting a code 44, but I have an idea where that is coming from.
After swapping the cap rotor and coil, the Burb developed a miss. I had time today to look at it and pulled the distributor to rebuild it. Afer getting it out the magnetic pickup was falling apart. No one had that piece so I got a new distributor. After getting it in, it is running good again. Yippie.
In retrospect, I suspect that there was a barage of problems with this. Short of replacing the MAP sensor, temp sensor and TPS, everything is new.
Pics to follow.
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Well this is great news! I s'pose it's too late to make that Maggie Valley thing? ;D. Now if we can just find you a window..
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Yeah, just a little late on that trip. The company I got the window from Friday better get me a new one for free since this one was bullseyed in the corner when I got it...
Next on the list is the rotting tailpipe....
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Cheese and Rice. So it was just a bad pick up coil... Well glad you got it straightened out!
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The last part was the pickup (that is when the miss started), but I believe the bad injector was slowly dying, which was the cause. I drove it some more today and still holding up fine.
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Figured i would pop in i have just finished fixing this very same problem on my 87 R10 with the 5.7 in it i replaced everything and the truck was still doing this i pulled the distributor this weekend and the pickup coil was severely rusted was almost locked up i replaced distributor and set timing at TDC and the truck runs better than it did when i first bought it hope i was some help if you haven't gotten it fixed yet
Chris
Sorry just checked and saw you found the same problem i had glad you got it fixed