I have a 2001 Tahoe with the 5.3 V8. When you start the Tahoe it is fine and then it begins to idle funny. The lights and dash dim and just goes down and back up down and back up until it warms up I guess. I have had the intake system cleaned and am not sure what this could be. Any ideas would be greatly appreciated!

Thanks

 

Faulty alternator?

 

sounds like the alt. to me to take it off and u should be able to get it tested for free at an auto parts store.

 

so, it idles funny huh, you think that the lights dim due to the engine rpm's dropping? well here's that i think.. you have bad intake gaskets, engine sucking in air and running lean. not lean enough to set a check engine light, although enought to misfire. The reason that this goes away when the truck warms up is that until the truck warms up the computer doesn't take any sensor readings into consideration and just runs on default settings. once it warms up and hits closed loop it reads the ho2 sensors and adjusts fuel accordingly.. or well one other thing.. if ur lookign at the engine, there is a fuel pressure regulator on the right side of the fuel rail, pull the vac hose off and if fuel comes out of there you have a bad pressure regulator "cheap" but this would usually cause an extanded crank. let me know.. oh yeah, to check for bad intake gaskets, take some carb spray and sray around the intake, if the idle evens out .. they're bad

 

have u checked your battery. some of the side post batterys (a c delco) have a problem with the + side terminal coming aprt inside the battery and it may look fine from the outside.

 

yo i just remembered.. those throttle bodies are messed up, you need to check on the scan tool to see how many volts the throttle body puts out when it's closed, and if it's too much then you have to replace the throttle body.. if it's within specs, you need to plug the little hole in the butterfly and adjust the throttle body

 

Any update on what the problem here was? I am having this exact problem as well and wanted to see what happened.

I am thinking alternator. If so next question is: what is the best way to get the belt of to remove it?

Thanks