Rough idle then smooths out
Thanks for any help.
I have a 1999 GMC Sierra SLT 2500 4X4 6.0
When cranking I get a really rough idle to
almost shutting off. After 3-4 min, the
engine will go back to perfect idle. I
replaced the fuel filter yesterday but it didn't
help this problem. I installed a new fuel
pump 18 months ago. Service engine light
is on but according to Advance Auto, there
are no codes. Please help!
Clean throttle body and clean or replace Idle Air Control valve or mass air flow sensor depending on which one you have replace fuel filter if have not done soon a while. As fas as the check engine light make sure the gas cap is on tight or may need replacing.
Ok, I will try these things. Thanks for taking your time to answer!
No problem just hope it helps.
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