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89 GP 3.1 - Running out of ideas...


Toxie

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Thanks in advance for any advice, I really appreciate it.

 

I'm starting to run out of ideas or things to check, hopefully somebody will have the answer.

 

I have an ’89 GP 3.1 non-turbo. This car had been running fine until last week. On the way home it was running fine and then all of a sudden just quit. I coasted off the side of the road and cranked it, It didn’t even fire. After a couple of more tries it did start but lacked power big-time. I limped back home about a mile away. The next day I tried to start it and again it started but had only half the power it should have. It idled for about 5 minutes and then just died. Since then it has not started again.

 

This is what I have done so far…

 

The ICM checked out as bad and I replaced it. I thought for sure it would take care of it but didn’t.

Coil packs all checked out OK

Crank Sensor – Replaced

Spark Plugs - Replaced

Plug wires - Replaced

Fuel pressure to the rail is fine – 40-42 PSI

Oil pressure sending unit – Replaced

When cranking the engine over the oil pressure is going up on gauge.

ECM – Replaced

I checked the ECM positive leads on the connectors per the GM shop manual and they both tested as positive, no shorts.

 

No spark or fuel. After cranking I pulled a plug and it was dry, didn’t even smell like gas. Checked the plug for spark and there is none.

 

It seems like the injectors are not getting the signal to open as there is fuel pressure to the rail, but no fuel in the cylinders. No spark to the plugs either…

 

Does anyone have an idea where to go from here? I’m running out of ideas... :willynilly:

 

Thanks,

Toxie

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Thanks for the reply.

 

AutoZone checked out the coils with a meter. They have been replaced already and are not original. They have 3yrs-60,000 on them. All thee coils checked out within specs but the ICM checked as bad so this is when I replaced it.

 

I checked the 20A fuse next to the battery in the engine bay and the 5A in the glove box, both are fine. I checked the positive leads to the ECM and they are fine. One stays hot and the other is hot when you turn the ignition on.

 

Thanks,

Toxie

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I know on the 89-90 Turbo Grand Prixs, there are a couple of Injector fuses in the fusebox on the passenger side front fender, check and see if you have those fuses, and be sure they aren't blown. I've come across a similar issue before on my friend's TGP and that was the problem.

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I am leaning towards a bad injector

 

On these cars, when a injector goes out, it takes out all 3 on that bank in a short circuit. Will cause really hard starts, if you can get it to start at all, and more issues.

 

Check the injectors.. Ohm out at 12.1 or better, it is good. 12.0 or lower its bad..

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Check for continuity on the wiring for the crankshaft position sensor. If that wiring isn't right (or if you got a bum sensor out of the box for that matter), the electronics won't even know the engine is turning, and you won't get fuel or spark.

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I know on the 89-90 Turbo Grand Prixs, there are a couple of Injector fuses in the fusebox on the passenger side front fender, check and see if you have those fuses, and be sure they aren't blown. I've come across a similar issue before on my friend's TGP and that was the problem.

Fuses are cheap, check them first.
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Check for continuity on the wiring for the crankshaft position sensor. If that wiring isn't right (or if you got a bum sensor out of the box for that matter), the electronics won't even know the engine is turning, and you won't get fuel or spark.

 

x2 and visually inspect it where it runs underneath the engine around the oil pan. I've seen it rub though there on a couple cars.

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First, I want to thank everyone for their replies; I appreciate your help more than you will ever know.

 

You guys rock!!

 

I got it running again! She’s running strong and smooth…

 

As suggested, I started out by checking all the fuses under the hood on the passenger’s side. Although the fuel injection fuse was fine, the DIS fuse was blown. I had checked the ECM fuses which were fine earlier, but based on the suggestion I just started pulling them all to check each one and the DIS was bad. Should I be concerned that it shorted out or does everyone think that when the ignition module went bad it caused the DIS fuse to short out also?

 

Again, THANKS!!!

 

:biggrin:

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Glad to hear it's running again! :high5:

 

Fuses are designed to blow if the wiring or device they are connected to either shorts or draws too much current. In this case, I'd say is is indeed plausible that the ICM could have shorted when it failed, causing the fuse to blow. Unless the car makes a habit of blowing the DIS fuse, I'd say you don't have anything to worry about.

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