What is the best way to disconnect the EVAP lines? Do they use a fuel line disconnect? When I got it to disconnect at the front it was with a lot of playing with it after I had pulled the valve assembly.

Thank you,

 

It should have a white/light grey lock that is spring loaded and will slide to one side to release. Then the line should slide right off. The rear disconnect is the same way.

 

I took the the intake off again and examined the intake and gaskets, and it appears that I had not cleaned it well when i put the new gaskets on and re-installed in originally. So I cleaned the intake ports and gaskets, as I examined them and did not see any damage.

I re-installed the intake again and torque them to the desired torque in the correct sequence.

It still seems to be idling rough and at first it sounded like the intake was still leaking when sprayed with carb cleaner on the passenger side. When I sprayed after it was warm I could not get the sounds I was getting earlier.

When I rev the engine the SES light flash and then go back to steady.

Should I replace the gaskets again, I have a set of felpro i picked up just incase I saw rips or the like in the other gaskets. The current gaskets werw just installed Sunday and I thought I might have been able to reuse them.

Anything else I should look for the PCV hose is attached and so is the other vacuum hose on the passenger side.

I think it is getting a bit better but still missing.

Thank you

 

Is it possible you damaged one of the spark plugs?

 

I am wondering if your fuel trims were compensating for the bad heads that you took off. When you installed the new heads, the trims were way off causing your problems. Another 500 miles should help a lot. Just a thought.

 

I do not think so, carefully installed them.

 

Hmmm, possibly, but the truck was running very well prior to the swap and now it is not. Was just replaced due to oil and coolant burning.

No SES lights prior to the swap.

 

Any way after removing and cleaning and re-installing the truck seemed to run better this morning. Today at lunch it was running rough, at idle and during acceleration, flashing SES again.

On the 2004 Avalanche I still only see the 2 vacuum lines, one to the pvc and the other to the passenger side valce cover. It is still acting like a leak and getting lots of misfires.

I there any reason people can think of why it would not have sealed as well as it should have. It was torqued in sequence to 44 in/lbs then to 89 in/lbs.

I am almost regretting trying to fix the truck but remoivingthe leaky heads, but I hated the smoke in the morning and the 1 quart of oil and coolant every 500-700 miles.

The truck is running much worse now, before it was just burning through fluids, now it is running very rough.

Would it be stupid to try and add RTV sealant on the intake gaskets? Has anyone done this. To me it is odd that the new GM gaskets just are not making a good seal.

Thank you.

 

flashing SES is a misfire.

Pull the spark wires, spark plugs and inspect. I'd replace all the plugs myself. It's cheap enough. NGK's are about $2 each.

 

You need to get it on a scanner and see exactly what cylinders are misfiring. You're assuming its the intake and it's possible it is something else.