Getting frustrated.
Asked by 1989Silverado Jan 31, 2021 at 11:52 AM about the 1989 Chevrolet C/K 1500 Silverado 4WD
Question type: Maintenance & Repair
I have a 1989 Chevy Silverado with a 5.7 that will not idle
without dieing.
I replaced the intake manifold gasket, complete distributor
assembly, plugs and plug wires. I had the position at TDC
and installed the distributor with the rotor pointing at the #1
cylinder. The vehicle will start and run fine at higher ram but
will idle very rough and die if I take my foot off the gas. I
started having this problem before I replaced the intake
gasket but nothing that I've done so far has helped at all.
Any suggestions?
8 Answers
beatupchevy answered 3 years ago
sounds like an I.A.C. valve problem if it has one . Spray some carb. cleaner down the throttle .
1989Silverado answered 3 years ago
Thank you beat. That was going to be my next replacment part to throw at this.
I agree, sounds like a bad IAC valve. Remove it and clean it with carburetor cleaner. Also clean the IAC passages in the throttle body. If you replace the IAC you will probably have to set the pintle length by hand before installation. Many GMs from that time period were like that. Hope that helps! Jim
I have an easy trick that may work. Find the hose that supplies air to the IAC. With the engine running spray carburetor cleaner down the hose. Then spray a little WD40 to lube the valve. This works on my Ford.
1989Silverado answered 3 years ago
Ordered a new IAC and will install it Saturday and update. Thank you!!!
You're welcome. Glad to help! Yes, please keep us posted. Jim
1989Silverado answered 3 years ago
Looks like that part did the trick but now idle is too high. I'm assuming that it's because I didn't adjust the pintle before installing.