TPI onto 86 Block

[VileZambonie]

Make sure the EGR is closed and no put no vacuum to it. As a matter of fact cut a piece of gasket material to block off the bottom of the EGR where it bolts to the manifold so it doesn't work and see what it does. If the valve is hanging open it will RLS

[123 pugsy]

Make sure the EGR is closed and no put no vacuum to it. As a matter of fact cut a piece of gasket material to block off the bottom of the EGR where it bolts to the manifold so it doesn't work and see what it does. If the valve is hanging open it will RLS

RLS?? =    Run lousy??

[CruzinHigh]

Pugsy, I had my EGR blocked off on my TPI setup I was running on the Camaro and it was just fine.  That fitting on your header looks ok for the ox. sensor, as long as it was a close distance to where the donor part was located you should be fine.  Even if it were too far it would just run in open loop operation non-stop (always think it was still "cold" thus en richening the mixture and running on a preset program for injector and timing maps).  I doubt that would duplicate the lazy on power throughout the RPM band symptom.

I do wonder about that cam though.  I did a 305 to 350 swap on my original TPI setup and I changed out the following items-

- All 8 injectors were swapped from the 19? lb. injectors up to 24lb. injectors.  (22 should be sufficient and is stock for the 350's of that era)

- If your fuel pump is a donor from a 350 it should be fine.  I upgraded to a 255 liter per hour Walbro pump though.  I doubt that would cause the lazy running symptoms you've got anyway.

- I had a custom PROM chip burned for MY application specifically - that included having a custom ground cam matched up to the PROM tuning as well.

- The comments about that camshaft really make me curious.  I think the Speed density / MAP setups on TPI systems are a bit more temperamental to modifications then were the MAF systems.  If your setup is significantly different than the donor car this TPI system came from, maybe we can begin to dissect exactly what is different and if it could have impact on your situation.   What I am getting at here is if your heads and cam are quite different than the donor setup the PROM mapping just won't cut it.  Although I must admit I have no experience of what the symptoms act like if you try to run too much motor with an insufficient chip.

- If you have no fault codes, I am wondering if it is something fundamentally wrong with the setup.  No loss of fuel pressure either, so we need to start considering the fundamentals.  Sounds an awful lot like cam timing or something.  Your ign. timing is right on, so what else would make it lazy throughout the RPM range like this?  With any injection system the first things are always checking faults and fuel pressure, and %99 of the time if neither are faulty and the symptoms persist its a mechanical issue. 

Does it knock or ping?  If it is knocking the knock sensor will retard the timing but not throw fault codes (I think.. somebody please verify that comment if I am wrong). 

Hang in there!  You'll get er running Pugsy.  And when you do, you will be really happy with the TPI.  It's a great setup.  A bit outdated these days, but still it is a great midrange torque setup. 

[123 pugsy]

Checked the TPS. Voltage is .57 throttle closed and then rising (smoothly) to 4.39 at WOT.

IAC has 54 ohms and 53 ohms resistance between A and B  and between C and D. I read somewhere these should be between 40 and 80 ohms.

I checked each injector (even though they were professionally rebuilt) and found 16.3 to 16.5 ohms.  Checked all the injector wires for continuity and checked out OK. 

[123 pugsy]

- I had a custom PROM chip burned for MY application specifically - that included having a custom ground cam matched up to the PROM tuning as well.

-

I wonder if the donor vehicle may have had a custom chip in it??

[123 pugsy]

I have the MAP sensor vacuum hooked up to the plenum. Is this correct or should it be hooked up to the intake or is the vacuum the same everywhere?

EDIT:

Disconnected the MAP wire harness and started the truck. Ran and stalled.
Gave a code 34. Appears to be working OK.

Checked the timing. Full advance is 23* at over 3000 RPM.

[chevyguy5894]

Sounds like a timing issue even though you stated what the timing was. My wife had a 91 blazer with 4.3 that it ended up being the module in the distributor.  It did the same thing as you described.

[123 pugsy]

I got to check the coil next. Also check the module. Now I just gotta figure out how to check these things....

I noticed the timing mark dancing around a couple of degrees when I held the light on it at idle. It stayed on the mark firmly at higher RPM's.

I'll eventually find something out of whack.

[VileZambonie]

Pugsy, advance your timing... bring it up to around 36° @ 3,000RPM. Yes RLS means what you said. What's your MAP voltage at idle when you backprobe the sensor? Yes it should be hooked to manifold vacuum. Did you put a vacuum gauge on it? Does the vacuum gauge read steady at idle?

[CruzinHigh]

- I had a custom PROM chip burned for MY application specifically - that included having a custom ground cam matched up to the PROM tuning as well.

-

I wonder if the donor vehicle may have had a custom chip in it??

...I guess that's not very likely.

Also I wouldn't really worry too much about that anyway, the chip should be close enough at least if both setups are close to the same. 

Yep, the MAP definitely goes to a feed from the plenum as well.

[123 pugsy]

[/quote]
..I guess that's not very likely.
[/quote]

Never know.The guy I got it from had a nice looking engine in his car.

Pugsy, advance your timing... bring it up to around 36° @ 3,000RPM. Yes RLS means what you said. What's your MAP voltage at idle when you backprobe the sensor? Yes it should be hooked to manifold vacuum. Did you put a vacuum gauge on it? Does the vacuum gauge read steady at idle?

I checked the MAP voltage from the computer key on engine off. I got 5.1 volts across 2 of the 3 wires.

Vacuum is at 14"hg at steady needle ( no bouncing).

I got the timing up to 34* full with same results. Still no power.

I think I'm going to stop playing around until I get the EGR solenoid installed and hooked up properly.

Also do I need a chip to disable AIR? Would this system not being hooked up cause problems?

[VileZambonie]

The EGR solenoid has nothing to do with it. Keep the timing around 36° total. Make sure the egr valve isn't sticking open at all. Vacuum is still at 14inHg after you advanced the timing? What's your map voltage with the engine idling? If you didn't hook up the A.I.R. don't worry about it. I know this may sound stupid but double check your firing order carefully and that you installed the distributor correctly. Finally unplug the knock sensor and take it for a rip to see what it does.

[123 pugsy]

The EGR solenoid has nothing to do with it. Keep the timing around 36° total. Make sure the egr valve isn't sticking open at all. Vacuum is still at 14inHg after you advanced the timing? What's your map voltage with the engine idling? If you didn't hook up the A.I.R. don't worry about it. I know this may sound stupid but double check your firing order carefully and that you installed the distributor correctly. Finally unplug the knock sensor and take it for a rip to see what it does.

EGR is brand new,so I'm certain its closed.
Timing full at 36* is 21* at idle. Vacuum steady at 10" hg.
MAP voltage at outside wire at idle is 5.01.
MAP voltage at center wire at idle is 1.73.
Firing order is good.
Haven't unplugged the knock and drive it yet. Perhaps tommorow.

[VileZambonie]

Your vacuum is really low!

Do you have any vacuum leaks? Does it run different with the oil cap off?

You are absolutely 100 % positive your firing order is good no #5 and #7 crisscrossed?

Your exhaust isn't plugged?

Your valves are not too tight?

Your cam timing is correct?

[123 pugsy]

Your vacuum is really low!
Do you have any vacuum leaks? Does it run different with the oil cap off?
You are absolutely 100 % positive your firing order is good no #5 and #7 crisscrossed?
Your exhaust isn't plugged?
Your valves are not too tight?
Your cam timing is correct?

Firing order is correct.

I will check again for vacuum leaks.

I will have to check it with the oil cap off. Well maybe not .One side has the PCV valve and the other side has a breather.

These are the heads I'm running:http://store.summitracing.com/partdetail.asp?autofilter=1&part=WRL%2D043600%2D1&N=700+400240+309119+115&autoview=sku

Keep in mind that this engine was running fine with an Edelbrock carb and intake before I installed the TPI. This same engine was pulling 22" vacuum. Nothing has been done to the engine or exhaust system.

A pic of the vacuum when it was on the test stand: