I just purchased a MY 2000 with 35,000 miles. The car is in great shape with the exception of an intermitent missfire at idle. The only mods to the engine is an Injen non-CAI intake that the previous owner installed. I had the spark plug update performed and also adjusted the valves to be sure of no internal problems. There is no vacuum leaks nor does there appear to be any problem with the DIS. The missfire is on all cylinders at about 700-800 rpm with no load. Any suggestions would be greatly appreciated.

 

How do you know they're misfiring?

 

Are you getting a Check Engine Light?

I think the code would be P0401- P0404, where the last digit coincides with the cylinder number.

 

The check engine light is on and I pulled codes with a Snap-on hand held tester. The codes were for all cylinders at virtually the same time. The actual values/snap shot of the sensors seemed normal for idle running which is what is confusing me. My only guess at this point is possibly a bad fuel pump/filter. Anyone know the specs for current draw on the pump and pressure at the rail?

 

What were the codes?

 

The codes were P0401 - P0404. At least I think that those were the exact numbers. They specifically noted each individual cylinder.

 

Low fuel pressure will definitely cause a no load, idle misfire. Other factors could be low compression, or poor fuel quality. Did code P0300 come up? This would indicate multiple misfires. If it acts up enough to raise the emmisions, it will trigger the MIL. If it does it enough to hurt the cat, the light will blink, indicating a more severe condition. Watch for that.

 

Thanks for the advice/info. Compression is good (220-245 psi) through each cylinder. Hopefully low fuel pressure is all that it is. Still, I can't seem to locate a spec. for pressure. Would greatly appreciate. Thanks

 

38-46 psi, and 47-54 psi with the vac line disconnected from the regulator.

 

[QUOTE]Originally posted by joe_s2k
[B]Are you getting a Check Engine Light?

I think the code would be