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Fits and Starts with Idle Control Valve (ICV)

I have a 1990 Chevy Suburban 1500, 350, automatic, throttle body, with 287,000 miles. I replaced the Idle Control Valve when I lost idle RPM, and it ran like a champ for about two weeks. Then, one day, it cut out on me at 65 mph, and started acting like the fuel filter was blocked. I changed the fuel filter, to no avail. Still acting like it has “bad gas” or water in the gas. Usually it dies when I am pulling into a parking space,or sometimes after stopping for stop lights. Any suggestions?

could be vacum leak, you could try putting it nuetural when coming to a stop to see if it dies on, you or keeps running.
a bad maf, or throttle position sensor could cause to die.

Did you clean the throttle body too?

Thanks for the prompt response. My 1990 Suburban does not have a MAF sensor, but does have a MAP sensor. Found one vacuum leak and fixed it, but still having problems. I will check out the throttle position sensor.

Thanks for the prompt response. Yes, I did clean the throttle body, but still having problems.

Try changing the ignition module. Check the ignition pickup in the distributor. If you don’t have any of these parts, there could be an ignition problem. Price a new or reconditioned engine control module (computer), especially if it resembles an aluminum box with transistors inside it.

Thanks for the prompt response. I have tried that yet, but will try tomorrow.

I have not tried that yet.

Have not been able to check ignition module. Crappy weather. Hopefully tomorrow.

I have also replaced the O2 sensor.

I have also replaced the O2 sensor.

I have also replaced the O2 sensor.

Hello Everyone,
After going though all my magic tricks, and all the helpful suggestions from all you wonderful people here on Car Talk, I finally broke down and took the suburban in, and paid for a diagnostics exam.

It turns out that both PROM chips were bad, and the ECM computer chip was also bad. So here are the part numbers:

PROM chip DEL 16060836 $ 71.76
PROM chip DEL 16139566 $123.05
ECM computer EC EM7747 $212.60

I hope this will help anyone else that is having similar problems.