I have a 1988 Coupe Deville with around 90,000 miles. The car had been sitting for a while before I got it. The engine was only hitting on 5 of the 8 cylinders. Also only one of the fuel injectors was fireing. We replaced the ECM and the car ran fine for about a week. Then one of the injectors quit fireing again. I assume there is a short in the wireing somewhere that is causeing the computer to fail. was this a common fault on this car? Any help would be appreciated.

I have an 1987 Seville and I think there is a problem with mines also....My dashlights and drivers information center is blank.....is this what's going on with your car also? If so what part would I have to buy in order to get it back on?

No my digital dash works fine. Have you tried checking the fuses?

yes but what are the name of the fuses(abbreviations)? and where are they located...in the fuse box under the hood that contains the relays or in the glove compartment?

I would check the fuses under the dash first. On my deville they are on the left on the drivers side. Just make sure they are all in there tight and none of them are blown. I don't know about any relays under the hood.

I have a 1988 Coupe Deville with around 90,000 miles. The car had been sitting for a while before I got it. The engine was only hitting on 5 of the 8 cylinders. Also only one of the fuel injectors was fireing. We replaced the ECM and the car ran fine for about a week. Then one of the injectors quit fireing again. I assume there is a short in the wireing somewhere that is causeing the computer to fail. was this a common fault on this car? Any help would be appreciated.
I would suspect a bad injector. Did you check the resistance on them? If you pull another yard ecm I would get the injectors as well and go ahead and swap them.

Steve B.

I have a 1988 Coupe Deville with around 90,000 miles. The car had been sitting for a while before I got it. The engine was only hitting on 5 of the 8 cylinders. Also only one of the fuel injectors was fireing. We replaced the ECM and the car ran fine for about a week. Then one of the injectors quit fireing again. I assume there is a short in the wireing somewhere that is causeing the computer to fail. was this a common fault on this car? Any help would be appreciated.


You can easily check those TBI injectors with a small, 9 volt transister radio battery. Just touch the battery terminals to the injector contacts and it will open the injector. Easy and quick way to see if the injector is giving up....

Check for 12 volts at one of the terminals at each injector. Disconnect the electrical connector at the injectors and check for voltage with the key on. One wire to each injector should get 12 volts all the time. The ECM turns the injector on by pulling the other side of the circuit to ground to the injector should always have 12 volts there even when it is not firing.

It sounds like an injector problem, honestly.

i luv my caddy, i had problems with my 88 seville with the dash lights it turned out to be the power supply module ?? power suppy somthin anyway its a silver box right above your brake pedal it has 2 bolts and is real easy to change i got mine from a junkyard for 20$