HELP!!! Not Enough Back Pressure at EGR???
I have been fighting the EGR for 2 months now tring to get my truck to pass emissions. Basically I think what it boils down to is the EGR is not getting enough back pressure from the exhaust. If you remove the vacuum line from the EGR, I have good vacuum there. But if I "T" in with the Vac. gauge at the EGR I dont get but -2 vac. What I believe is happening is when the EGR opens the back pressure drops and the Modulator doesn't stay closed causing a vacuum leak. Modulator has been tested on another truck and works fine.
Any Ideas on fixing back pressure? I tried a 1 inch restrictor plate and it didn't make a difference. I had to basically totaly block the exhaust to get a -5 vac reading.
Edit: Compression readings are 140-80-145-55, probly got some burned valves.
New Compression Numbers 160-160-165-125
Im thinking maybe I have an internal crack in the head causing low pressure to EGR?
Last edited by FieroGTdude; 09-27-2011 at 04:59 PM.
Reason: New Compression Numbers