Fits and Starts with Idle Control Valve (ICV)

Maintenance/Repairs
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1

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?

2

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.

3

Did you clean the throttle body too?

4

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.

5

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

6

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.

7

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

8

I have not tried that yet.

9

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

10

I have also replaced the O2 sensor.

11

I have also replaced the O2 sensor.

12

I have also replaced the O2 sensor.

13

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.