Ok I have posted many threads about my problem on here. Long story short the car overheated and blew gaskets and spun bearings. Through trying to determine the problem, I tried starting it a few times after it sat. Upon trying to start it once, I heard a loud pop through the speakers. Put a new motor in it, rebuilt the trans, no fire. Replaced the computer, and fried it. Took it to a shop, they determined the short was in the wire running to the torque converter lockup solenoid. He clipped the wire, tried another computer, and fried it. Now they don't know where to turn.


A carb'd v8 is looking better and better all the time.....

 

Electrical is always tough to track down. You need a lot of patience and a methodical approach to isolating the problem and either fixing it or bypassing it. You could always carb the v6 if you can't fix the computer. But it sounds like you'd still have an electrical problem either way.

 

Basically all you have to do is disconnect the ECM and probe the wires entering the connectors. You can either use a test light that has the clip connected to battery voltage or a multimeter. Probe each and every wire at the ECM. The only wires that should show ground (with either zero resistance on the meter or a lit test light) are the black/white ones. NONE of the rest should have any connection to ground (with the exception of the tan wire running as an O2S ground). Either they have power (orange and pink, pink/black), send a signal (generally blue or gray), or the ECM provides ground (except for the fuel pump and coolant fan relays which it provides power to for some reason, these will have resistance on them that isn't open due to measuring the coil resistance in the relay).

You probably pinched a wire somewhere reinstalling the engine and reassembling it... And the pinch cut through the insulation and is grounding out a wire.

 

See the thing about the whole pinched wire thing is that the computer fried before I pulled the engine. Which is what is so boggling about this situation.

 

I'd still get down there and start probing wires... Could be some part of the harness got hot and melted to the exhaust or something (exhaust leak, probably on the passenger's side near the starter). Like I said, only wires going to ground should be the tan for the O2S ground and the black/white ones. If the ECM is getting fried the instant you put ignition power to it, you've got something grounding that isn't supposed to be.

 

agree with maverick. i had the same issue last summer. melted wire wire grounded out kept popping ecm fuse. fixed wires and added new plastic conduit in the bad spot.

 

Oh, and also check the resistances of each of the solenoids (injectors, canister purge, EGR) to make sure they're not fried either... Injectors should be no less than 11 ohms (using the 90-92 specs and not the old ones), and the others should be higher, around 2K ohms, IIRC.

 

I'm not sure if you resolved this yet, but due to the tight clearance, it is very easy to get the transmission wire harness pinched between the enging and bell housing when installing the trans on the automatic cars. The wire harness contains wires for the lock up solenoids, the speed sensor (on the 91-92's) and the back up light switch on some years. pinching these wires between the trans bell housing & engine block will cause one or all to short to ground and may be a possible cause of the problem.