Changed injectors, now it doesn't start.

[Canyonero]

So, on the Trooper 3.4L SFI conversion project: I got it running and driving, however it was running super rich. I had an injector (#3) that was leaking terribly. I have a spare set of injectors from a bundle of parts I bought (from a similar 93-95 SFI 3.4L), unknown condition, but I was hoping they at least wouldn't be AS bad. The part number stamped on them was different than my originals, so I opted to switch all the injectors to keep everything the same. Stupidly, I didn't make note of the number before I installed them. Anyway, I got everything is back together and it fired right up. Ran for a couple seconds, then died. Since then, I get NOTHING. I have spark, I have fuel pressure, I have 12v to the injectors (no noid light to test though). The spare injectors are the same impedance as the original ones.

I can only assume that I roasted the ECU somehow. I did blow a fuse on my custom wiring harness at some point (which is unlabeled of course). I never disconnected the battery while I was working on it; again, kind of stupid. The fuse (10A) has been replaced and it holds.

I have another ECU from an automatic equipped vehicle (Trooper is a 5-sp). I tried swapping that in, still no fire. My harness does have a VATS bypass built in, any idea if that is specific to the ECU? I'll call the place that made it Monday morning to find out for sure.

Any thoughts?

[IsaacHayes]

Well if they are the same impedance then I doubt that fried it. And I've take apart stuff with the battery still connected so I don't loose the calibrations that the ECM adjust to since my car is no longer stock and it takes a while for it to re-learn. I only disconnect it when I might short the battery or short a connector. But disconnecting a few sensors if the car isn't switched on I can't see as causing a problem.

How did the fuse blow? 10a is pretty big.

What ECM are you running?? From what car? Is it a 3.1mpfi ECM with modified code for a 3400? Or a 3400 ECM?? If it's the later then it could be the VATS since it will run for a few secs then shut off the car if it doesn't get it's signal. We gotta know what ECM you are using... hehe. spill it! (car, engine, year, etc)


EDIT: you said 93-95 3.4SFI... Is it not a 3400 but a 3.4 1st gen iron head fbody motor?

[Canyonero]

It is an unmodified F-Body engine, stock ECM. I was going to get a set of noids, but the parts place apparently closes at 1:30 on Sundays now.

I left the battery disconnected overnight to see if that would clear something, but it still wouldn't fire.

[Canyonero]

Looks like I have trigger pulse on the injectors, so now it's looking like all my injectors are clogged. They were sitting around for a long time still connected to the fuel rail full of stale gas for years.