Engine Performance problem
2000 Mazda Truck 4 cyl Two Wheel Drive Manual 156000 miles
The motor starts fine and idles smoothly when cold. Give it a little gas while cold and it starts to misfire like a plug gets fuel fouled. If it dies, it's hard to start. When driving while cold, it dies instantly after pushing the clutch in when rolling to stop.
The motor idles fine when hot. When accelerating and shifting gears, and letting the clutch out, the motor stumbles while attempting to accelerate in higher gear. (Lean misfire?) Shift points around 3k rpm.
Manifold vacuum is at 18-20 in/hg at hot iidle. When checking manifold vacuum, and revving to 2k rpm, motor dies when throttle is closed.
No consistent ECU codes. Have had random "cylinder #1 misfire" and DPSS EGR codes over the past year.
New plugs and wires.
No exhaust blockage.
Vacuum checked EGR valve function, o.K.
New PCV valve.
Spray tested for external vacuum leaks.
have the same problem?
Wednesday, September 30th, 2009 AT 8:59 AM