marcus_booth

Hey guys, so i think my ecm may be dead. The car barely cranks unless jumped and does not start, no gas come out of the injectors even though theres pressure into the tbi. My check engine light does not come on when the key is in as it usualy does, and it doesnt light up to check error codes either. Is there any surefire way of testing the unit to see if it works before I buy a new one?

nater

well first off if the battery you have isnt new replace it. a dead battery can cause a lot of problems, especially with cranking. next back off the timing a bit and check grounds and fuses. maybe even try some ether down the tbi and see if she will fire. the symptoms you are describing with the check engine light(CEL) seem to be the common ones with bad ecms. but things to note would be that the CEL is not an LED and can burn out or can be taken out my a previous owner. also i would bet more on a ground or fuse than the ecm, unless it were severely fried the car should start but not run well, where as yours seems to not be hooked up at all. if all fuses are good then move on to fusible links near the battery, and make sure the wires around the links are good too. the ecm wire i believe is orange and should run just below your coolant overflow tank then almost strait to the battery.

OrangeBird

iTrader: (1)

Oh I'm sorry , but , this is by far the worst advice I've ever seen on this board !!!!!!!

If your injectors aren't spraying fuel , NO amount of dinking with twisting the distributor is gonna cure that ! You need to troubleshoot this by staying focused on the actual symptom presented , no injector pulse , and forget about things that can't possibly cause your problem . I don't care if you have your timing even 50 degrees advanced or retarded , it will still spray fuel as long as the distributor is turning while cranking the engine with the starter , providing you have a properly working fuel system . Now , giving Nater some credit here cause the rest of his post is spot on , I'll say the first thing to do here is to check the fuses as he mentioned , both "inj 1" and "inj 2" in the regular fusebox as well as the fender mounted fuse (usually near the radiator) that supplies the ECM with power and also yes like he said replace the battery . If the fuel rail has pressure does that mean your hearing the 2 second prime at key on ? Or is the oil pressure switch running the pump as your cranking it with the starter ? You say you have no activity of the check engine light whatsoever ? before you condemn the ECM you do need to make sure that it's actually getting power and that fender mounted fuse really needs to be checked out as your first action after you put the new battery in .

Checkrazer

I lost spark and fuel a
t the same time could that be a bad ecm