What's wrong with the motor when it's idleing but continually try's to shut off but doesn't shut off ?


Asked by Oct 30, 2014 at 10:12 AM about the 1991 Chevrolet C/K 1500 Silverado Extended Cab SB

Question type: Maintenance & Repair

When it's idleing in any gear, it'll run
fine for a minute or 2 then the RPM's
will go all the way down and the
motor tries to shut off but it doesn't
shut off but instead idles back up to
800 RPM's. Please help.

5 Answers


The idle air control valve controls your idle. I would first look for a vacuum leak. There are only a couple vacuum line on that motor. Also i would pull the codes on the truck. Jump pins A and B with a jumper wire and count the check engine light flashes. If no codes or vacuum leaks, i would remove the IAC valve from the throttle body and clean any carbon build up from the IAC and the port it rides in. Also make sure the wires going to the IAC and the connector are in good shape.

Best Answer

It would help you get a more accurate answer to your question if you can provide more information on your truck - what engine, how many miles, fuel injected, throttle body, or carburetor, etc. There are multiple reasons for this. Without knowing which engine is in the truck, it makes it difficult to give an accurate diagnosis. I would start with the fuel system - carburetor or fuel injectors. When the gas tank is near empty, add a high quality fuel additive (carb or injector cleaner) and then fill the tank up with some 93 octane fuel. This is the easiest and cheapest first option. You can also take the truck to a Midas store. They will plug in their OBD tester to see if you have an stored codes. That would be my starting point. Best of luck.


It has a 5.7 v8, 2 wheel drive, 248,000 miles, and it's a fuel injected.


I'm going to assume (you know what the say about assuming) that your truck its throttle body injected. Check your fuel pressure at with the key on engine off and at idle. Im not sure what the pressure is suppose to be. I think its 15 psi or around there. It should be steady and not dip in any way.



Your Answer

Add photo

Related Questions

  • 1995 Chevrolet 1500, 4.3, 2wd: Engine will shut of anywhere or everywhere- control gauges go crazy, radio stops, truck will die on the spot! 2 answers

    1995 Chev. 1500, 4.3, 2wd: Engine shuts-off for no apparent reason. Truck doesn't sputter, but the engine gauges go crazy, plus the radio goes on and off too.

    1995 Chevrolet C/K 1500 Cheyenne Extended Cab LB 4WD


    Maintenance & Repair

  • 92 chevy ck1500 engine shutting off 5 answers

    My 92 chevy ck 1500 5.7(Has fuel injector not carburetor).will start up and die again. I have to rev the engine to keep it going. Then once begin to drive about 5-10 sec later I can hear the engine...

    1992 Chevrolet C/K 1500 Standard Cab SB


    Maintenance & Repair

  • 1994 Chevy C1500 5.7 bogs/backfires when I give it gas. 34 answers

    My truck bogs down (and tries to die) when I give it gas to accelerate off of a stop. There is often a backfire or two when this happens. Pumping the gas does not help. I basically have to crawl thr...

    1994 Chevrolet C/K 1500 Silverado Standard Cab Stepside SB 4WD


    Maintenance & Repair

  • Car shuts off

    Car starts up but after awhile it shuts off. I replaced the fuel filter, the pump and everything on the car is new. My right tail light stays on and does not go out unless I take the fuse out for ...

    1995 Chevrolet C/K 1500 Silverado Extended Cab LB


    Maintenance & Repair

  • Grinding noise after the head lights shut off 7 answers

    When the head lights are shut off and they do go down like they should. There is a grinding noise like a motor trying to do something, after the lights are down what is this

    2000 Chevrolet Corvette Coupe


    Maintenance & Repair

C/K 1500

Looking for a Used C/K 1500 in your area?

CarGurus has 1,131 nationwide C/K 1500 listings starting at $2,400.


Search Chevrolet C/K 1500 Questions

Chevrolet C/K 1500 Experts

#1 Andrew Olsen
Andrew Olsen
Reputation 2,610
#2 John Saffrahn
John Saffrahn
Reputation 2,260
#3 Rowefast
Reputation 1,190
View All

Related Models For Sale

Used GMC Sierra 1500"
1,024 Great Deals out of 56,287 listings starting at $2,499
Used Ford F-150"
3,181 Great Deals out of 216,388 listings starting at $1,900
Used Chevrolet C/K 2500"
279 listings starting at $1,995
Used Chevrolet S-10"
11 Great Deals out of 1,819 listings starting at $1,749
Used Chevrolet C/K 3500"
301 listings starting at $5,600
Used Chevrolet Camaro"
812 Great Deals out of 38,799 listings starting at $2,650