Engine Performance problem
2000 Chevy Express V8 Two Wheel Drive Automatic 70,000 miles
Engine would occasionally barely run as if running out of fuel. Turning off and then re starting would clear problem. There are some hesitation problems during acceleration. A lean fuel mixture code was occasionally triggered. Pressure test of fuel system revealed low pressure. Replaced fuel pump, pressure regulator. Pressure is 62 at initial key on then drops to 54 or 55. Jumps back up to 62 at key off. Engine still hesitates on acceleration though fuel pressure rises to 62. When throttle punched or vacuum disconnected. Interestingly I forgot to re-connect the electrical connections to the MAF at one point and the engine runs better without hesitation though fuel pressure remains arond 54, reconnecting MAF decreases performance. Any Ideas?
Wednesday, June 9th, 2010 AT 2:02 AM