82 Cross Fire Engine Not Running

[Jim Squatrito]

I have an '82 Cross Fire Injection with intermittent TBI operation. Fuel sprays properly for about 1/2 second, than fuel stops for 1/2 second, than sprays for 1/2 second, than stops, etc. This problem occurs no matter what engine RPM. The car is not driveable. At idle the engine usually stalls, and under load it always stalls.

Any suggestions?? I have checked the ECM fault codes and there is a 22 fault -- TPS. I really doubt that the TPS is causing the fuel delivery problem, but anything is possible.

[William C.]

Re: 82 Cross Fire Engine Not Running

Well, as the tps is one of the things that tell the engine how much fuel to deliver, you might start there. Do you have a check engine light on while the engine is running?

[Donald Brunswick]

Re: 82 Cross Fire Engine Not Running

Check the TPS setting per the manual. Make sure the fuel pump is getting 12v all the time, check the fuse for the fuel pump its hard to get to and will overheat and develop a resistance at the fuse. They way you describe the injectors they could be ok though. Most stalling poor performance on a xfire is from vacuum leaks. Check for the usual hose leaks but check the intake manifold cover, it is notorious for leaking.

donald

[jim squatrito]

Re: 82 Cross Fire Engine Not Running

Tonight I checked the TPS voltage and it was reading low at .416 -- I adjusted the TPS to get the voltage within spec and was able to set it at .533. When I tried to start the engine, there was no change in its performance. I have had the intake manifold gasket replaced about 1 year ago -- there was a vacuum leak that was causing the idle speed to be high. The on/off pattern of the fuel spray is consistent causing the engine to have a rythymic surge/near stall pattern.

I will check the fuel pump fuse. Any other ideas?

[William C.]

Re: 82 Cross Fire Engine Not Running

Check the fuel pressure while running, let's try to find out if there is a variation in the feed pressure, or if the injectors are seeing bad pulses.

[Joe C.]

Re: 82 Cross Fire Engine Not Running

Jim,

Even though the TPS is itself functioning properly, that does not mean that the ECM is seeing the correct voltage. Check the TPS wiring from the rheostat to the ECM, for continuity. Also, clear your trouble codes, and see if it resets a code. The oscillation is due to a lean mixture.
If TPS and associated wiring are all AOK, and the ECM resets a "TPS" code, then it's possible that you've got a problem with your PROM chip and/or ECM.
Normally, any mechanical problem, such as a vacuum leak should not set a trouble code. The only codes you might see under such conditions are "Lean/rich fuel mixture".

Joe

[jim squatrito]

Re: 82 Cross Fire Engine Not Running

Tonight I reset the ECM and checked the fuel pump fuse. I also checked the wiring from the TPS to the ECM. The fuel pump fuse looks like it is fine, and the wiring is also fine. After getting the engine to run for a few minutes, the ECM now has no faults. So, I have corrected the TPS fault but the engine problem still exists. Does this lead to an ECM problem??

[Donald Brunswick]

Re: 82 Cross Fire Engine Not Running

Not likely, from my experience with them they either work or don't not much in between.

donald

[Joe C.]

Re: 82 Cross Fire Engine Not Running

Jim,

If the ECM does not set a code, then the ECM should be fine. You might look for a vacuum leak. Does the ECM go into "closed loop" operation? '84 might be similar, but for '85, if you short ALCL terminals "A" and "B" with the engine running, the "check engine" light flashes quickly in open loop. Once the O2 sensor gets to op-temp, the system goes into closed loop, and the flashing frequency halves. If you have a mixture problem, and no code is set, the engine probably will never see closed loop operation.

Joe

[jim squatrito]

Re: 82 Cross Fire Engine Not Running

Tonight I checked the "closed loop" operation. When I first started the engine, the "check engine" light was flashing rapidly with the "A" and "B" terminals of the ALCL shorted. After a few minutes, the check engine light stopped flashing. It didn't go to a slower flash rate, it just stopped flashing. For what it is worth, from the smell of the exhaust, the engine seems to be running very rich -- not lean. So....something happened after the engine warmed up for a few minutes and I am not sure if this is the "closed loop" mode or not. This is a 1982 ECM and I am not sure if it operates the same as the '84 or '85. Does all of this mean anything??

[Dick W.]

Re: 82 Cross Fire Engine Not Running

"Open Loop" would be a very rich condition, much like having the choke set on a carbureted engine. Your engine should have changed over to "closed loop" once it warmed up.

[Joe C.]

Re: 82 Cross Fire Engine Not Running

Jim,

1982 is the same as 1984!!!! 1985 with TPI MIGHT be different. Do you have the shop manual for your TBI (Throttle Body Injection) setup?? For 1985 thru 1991 (TPI L98)there is NO provision for a non-flashing condition. If you would like clarification, then please e-mail me.

Joe