Inconsistent rough idle when warmed up

[Malibu-Taylor]

Hi all,

Looking for a little help. Recently took my 02 excursion to he shop to have a fuel leak fixed. At the time it was running great with no problems other then a leak. Mechanic found the ICP sensor needed to be replaced and I had him change the fuel filter while it was there. Get it back and now it has an inconsistent rough idle when it gets warm. Rig has 119k on it and a lot off life yet. Engine is flashing no codes so its an old school trouble shoot! Mechanic did a common "buzz" test and said there were no problems. Has anyone else ever had this problem?

[Eric]

Subscribed. I'm having what sounds like the same problem you are

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[Malibu-Taylor]

I recently tried a fuel additive and it seemed like it went away. While stopped at a light kinda stepped on it a bit and the idle problem came and went again? Puzzled any ideas?

[vince harding]

I think a buzz test is testing that the injectors are working. But injectors orings that are bad usually gets worse as the oil gets hotter and thinner allowing more oil to leak out causing the engine to run ruff. Their could be air in the fuel system but usually it clears itself up because its not a high fuel pressure engine. Sounds like a fuel issue if it was running done before it was fixed.

[beerknight]

Originally Posted by Malibu-Taylor

Hi all,

Mechanic did a common "buzz" test and said there were no problems.

Was the truck warm during the "buzz" test? If so, the test can be faulty. A few of the old injectors in my truck buzzed just fine when warm, but did nothing when cold.

[Malibu-Taylor]

Hey thanks for the input! Yes it was warm when we did the buzz test, I'll try to get it back down there again to try when it's cold. Today we also switched out the ICP sensor again to see if that was the issue. Also did a compression test and all looked great. Mechanic now says he is seeing a code on #8 cylinder but not sure what is causing it? I'll keep posting til we find the issue