HI all,

So, I'm not sure if I should post this here or in the TBI section, but, here goes...

My '82 Cross-Fire T/A has seen limited use the past few years as family and work consumed most of my days. It's never sat and always gotten out for a few times during the summer, but this year I've had it out a lot more, to the point that it started misbehaving this past Monday.

As I was driving it into work, the RPMs just plummeted and it was like the car was choking almost to the point of stalling, and then in the next blink of an eye it would all kick back in at full power. The unexpected surging every few minutes made an hour drive quite unnerving. So, I brought it to my mechanic and after checking the usual stuff, like clogged fuel filter, blocked air passages and the like, he started looking at the power system and the TBI set up. He found that although the fuel injector on the Driver's Side is working fine (as is the throttle body itself), while the car was running it would on occasion cease to send any power to the injector itself and thus the injector would be dormant and not, well, injecting; turning my smooth driving 8 cylinder car into a wild 4 cylinder.

He's nearly done going through all the wiring, grounds, and other related connectors, but he told me that he's starting to lean towards the ECM, or a part or connection on it, that may be failing after all these years. Before jumping into replacing the ECM and while he finishes up his diaging tomorrow he and I both thought it'd be a good idea to bounce this off of you fine, knowledgeable folks here on TG.

So, if anyone's experienced this phenomenon before on their '82/'83 Trans Am/Camaro, or '82/'84 Corvette with the Cross-fire TBI setup, please feel free to chime in with your thoughts or ask any questions. Thanks in advance, all; your insights are appreciated as always.

- Xanath

 

Now I've never worked on a cross-fire car, but unless it's radically different from other FI systems - the power should be ignition switched and the ECM controls the injector ground signal. So if it's losing power, that has nothing to do with the ECM. The injector should receive constant +12v any time the key is in start or run.

If it's losing injector ground signal from the ECM then that's a different color of horse. At that point you have to determine if the ECU is getting stable power and ground itself, and also a stable reference pulse from the distributor.

GD