Fuel pressure test 48lb. when running, turn off key go's right to 42lb. holds 35lb. after 1 hour? Replaced fuel filter. checked catalytic converter can see it's visually clear? This all started with check engine up stream co sensor replaced with denso next check engine mass air sensor replaced with denso, no more check engine light!! This 3.4 engine has cable control throttle,and fuel regulator vacuum line go's to in take air not manifold vacuum? Checked and that' correct! Has me stumpt!! THANK'S
check for vacuum leaks
I will check for vacuum leaks!! If I would put a vacuum gauge on manifold what would be the average reading? Thank's for the help11
Thank,s MoumtainManJoe!!! Scotty kilmer makes some good point,s easy to follow111
15 - 20, if the engine is good.
Checked for vacuum leaks didn't find anything!! manifold reading 19lb. at idle.
Still stumpt !! Could it be throttle position sensor?
MAF, MAP, IAC, TPS??
Doc thank,s for the help!! No check engine light?? Don,t know MAP or IAC and can they be bad without check engine light ? what would suggest HELLLP........