I miss carburetors

That black film is oil from that K&N filter mixed with gas vapor. It is one of the reasons why GM and others are starting to void warrantees on vehicles that have them installed.

Buy some GOOD spray carb cleaner and a toothbrush and clean the TBI real good. Then run some Techron cleaner through it. Also pull your EGR valve off and clean it out since it probably has carbon that is blocking it open enough to effect the idle. Very common with the 4.3.

Sounds like the EGR valve is stuck open..perhaps a cleaning as already suggested is in order

How do you recommend I clean the EGR? I don't see a way to dismantle it. I did spray some B12 Chemtool down into it several times. Gave it a good shaking, and each time had a fair amount of C come out. Is there something more I need to do to clean it?

Thanks, Charles

Steve W. wrote:

Basically pull it off the engine. Hold the pintle open and use a wire to poke around the pintle and break up the carbon. Then use some good carb cleaner to flush the crud out. I also use a stiff pipe cleaner to get the loose stuff. Clean the port in the intake as well. There is a screened gasket available for the 4.3 that will stop the carbon chunks from sticking the pintle open. I recommend it very much.

Cleaning the TB and EGR may work but it is more likely the MAF sensor. This is a common problem with KN. A little over oil and the MAF sensor gets coated and doesn't read the correct air flow. Hell clean everything can't hurt. If EGR was stuck you would have a service engine light.

Just for the record: I do NOT miss carburetors.

I'll look at that, too. There's been no service engine light.

Thanks, Charles

sensor. This

Depends on how far open it is. I have had a couple open just enough to cause a vac leak that didn't set a code.