Car runs for 10 miles or around 15 minutes or OPERATING temp, and shuts off. Won't start back up until it cools back down. During this time, diagnosis of going through with a test light says the opti is bad, but why would it keep on running then just shut off after 10 minutes? I've replaced the opti, cap, rotor, ICM, and coil.

 

Sounds like the fuel pump is gertting hot and shutting failing.


When It dies check the fuel pressure.

 

Scan it for codes. check fuel pressure once it shuts down. Check for spark once it shuts down. If all that looks good, try squirting fuel in the intake while someone cranks it over(after it shuts off).

 

we tried for spark after it shuts down and doesn't get anything. I just got back in town from school (my parents were nice enough to let me borrow one of their cars for the week ) and my dad is driving the car as far as he can to a GM dealership (with our neighbor following just in case it needs to be towed) to be scanned and check everything. I'll let report to yall once I find out hopefully they can help, but we all know dealerships aren't always the best....

 

i put my money on the ICM

 

It wouldn't hurt to troubleshoot your way through the ignition system, it seems like you have replaced alot of parts without much luck. http://shbox.com/1/4th_gen_tech2.html#opti_test

 

Sounds ignition related...a lot of ignition gremlins surface once the car is up to operating temp...I had an ICM and some bad wires work perfectly when the car was cold, and then fail when it got warmed up.

 

Took it to the dealership to get scanned for codes.

And the dealership said they couldn't diagnose it further because I have "so much aftermarket stuff" on the car but it is throwing codes P0300 (miss on #4) and P0100 (mass air flow sensor).

I have troubleshooted threw the ignition system but I used another person's write up. I'll have to try that one.

 

thanks for all the input too

 

I'll second the ICM. I just had the WORST time with my ICM module. Try testing it.

 

Have you changed the plugs and wires recently? I would also look further into the MAF code, that could lead to some odd driveability issues if it is malfunctioning.

 

plugs and wires are less than a month old. And i know the MAF is causing the #4 misfire code too. getting another icm here soon

 

So you have a misfire code that is cylinder specific? If so, I would look at that cylinder, are you positive that the plug is in good shape and completely threaded into the head? Is the plug wire in good shape as well. Also, a dirty/clogged fuel injector can lead to engine misfires as well.

 

the car isn't misfiring at all tho, plugs and wires are brand new and I've checked and re-checked all that stuff. It simply runs for about 10-15 minutes or around 10 miles then shuts right off or once it gets up to operating temperature.

 

Try to get the vehicle stall in your driveway/garage. Just let it idle. When it dies play close attention to the dash. If it just dies off and there aren't any lights illuminated on the dash, SERVICE ENGINE, AIR BAG, ABS INOP, CHECK GUAGES, ect.. That's the biggest sign your ICM is shot. Try to test it. shbox has a helpful right up.


http://shbox.com/1/4th_gen_tech2.html#opti_test

Another is this.. I am borrowing from slopokrodriguez.

The signal from the PCM to the ICM is on the white wire of the ICM and goes to pin B and at the PCM is on the black connector pin 5. The first thing to do is disconnect both connectors and check continuity from pin B of ICM to pin 5 of the PCM connector. You may need a second wire to reach it with meter. Obviously if there is no continuity, you have a wire to fix.

If ok, connect both ends and put the meter on AC Volts. While cranking the engine, look at the signal on the white wire of the PCM. It should have between 1 and 4 volts AC on it. Remember to ground the black lead.

If no AC signal, pull the connector at the PCM (black connector) and check the signal coming out of pin 5. If there is no signal coming out of pin 5 then most likely (notice I said most likely), the PCM is bad.

If the AC signal is getting to the PCM on the white wire, you must now look at the signals from the ICM to the coil. Ignition off. Meter set to DC Volts. First check for a good ground to the ICM. Put a meter lead on the + battery terminal and probe the black wire pin C on the ICM with the other lead. It should show a full battery voltage (12 or more volts).

If not you have a bad ground.

Ignition on. Meter set to DC Volts. Now check the pink/black wire on pin A of the ICM and the white/ black wire on pin D of the ICM for battery voltage (12 or more volts) remember to ground the other lead.

If the voltage is there, the problem is the coil. If it is not on those 2 pins, you have to determine if the wire from the coil to the ICM is broken, or if the connectors are bad or the coil is bad.

Also if the voltage is not on those 2 pins, check the #11 fuse (10 amp) the supplies the ignition. If blown, no voltage either.

If the AC signal is getting to the ICM and the ICM has 12 volts on pins A and D, the ground is good to the ICM, and you still have no spark the ICM is probably bad.