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Author Topic: TBI Burb dying in gear, My Turn.  (Read 62322 times)

Offline VileZambonie

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Re: TBI Burb dying in gear, My Turn.
« Reply #45 on: May 26, 2007, 11:31:26 am »
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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Offline Captkaos

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Re: TBI Burb dying in gear, My Turn.
« Reply #46 on: May 26, 2007, 05:21:41 pm »
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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Offline Captkaos

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Re: TBI Burb dying in gear, My Turn.
« Reply #47 on: May 26, 2007, 06:16:01 pm »
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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Offline Toolmaster

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Re: TBI Burb dying in gear, My Turn.
« Reply #48 on: May 26, 2007, 06:45:09 pm »
Did the ECM Fix it ?????????
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Offline DnStClr

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Re: TBI Burb dying in gear, My Turn.
« Reply #49 on: May 26, 2007, 07:31:36 pm »
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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Don
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Offline Captkaos

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Re: TBI Burb dying in gear, My Turn.
« Reply #50 on: May 27, 2007, 12:27:25 am »
Welp, new ECM did nothing...  Same problem, dies when going into gear...
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Offline VileZambonie

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Re: TBI Burb dying in gear, My Turn.
« Reply #51 on: May 27, 2007, 08:25:26 am »
" 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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Offline VileZambonie

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Re: TBI Burb dying in gear, My Turn.
« Reply #52 on: May 27, 2007, 08:27:43 am »
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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Offline Captkaos

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Re: TBI Burb dying in gear, My Turn.
« Reply #53 on: May 27, 2007, 12:45:45 pm »
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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Offline DnStClr

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Re: TBI Burb dying in gear, My Turn.
« Reply #54 on: May 27, 2007, 05:16:59 pm »
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
« Last Edit: May 27, 2007, 05:26:28 pm by DnStClr »
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Don
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Offline Captkaos

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Re: TBI Burb dying in gear, My Turn.
« Reply #55 on: May 27, 2007, 06:44:24 pm »
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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Offline VileZambonie

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Re: TBI Burb dying in gear, My Turn.
« Reply #56 on: May 27, 2007, 09:04:19 pm »
disconnecting what = nothing?

Do you have another TBI you can throw on there?
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Offline Captkaos

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Re: TBI Burb dying in gear, My Turn.
« Reply #57 on: May 27, 2007, 11:27:22 pm »
Disconnecting the EGR...

I have one that needs complete rebuilding, and the one on my DD.
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Offline VileZambonie

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Re: TBI Burb dying in gear, My Turn.
« Reply #58 on: May 28, 2007, 08:42:24 am »
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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Offline Captkaos

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Re: TBI Burb dying in gear, My Turn.
« Reply #59 on: May 28, 2007, 09:27:39 am »
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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