Upon cold start up or after truck sits for an hour or so starts fine and idles fine but it loses engine responce, it will tach up very limitedly and you have to feather on and off throttle during wich time it detonates in the exhaust like it is running very rich after a couple of miles it comes out of it with a couple of surges and runs okay, on long idles it skips and acts up and if you shift to neutral it usually fixes the problem. No check engine light on for awhile, awhile ago had O2 sensor sensing rich condition but cleared and hasn't come back on even with the ping in the exhaust.
Put new plugs and wires on, tested Map sensor okay as far as my vaccuum to ohms test. I am a diesel mechanic with limited knowlege of gasoline systems but can read and understand directions. Please help, it has both me and my boss stumped.
SPONSORED LINKS
Monday, July 27th, 2009 AT 2:48 PM
