flashing check the engine light

[ortonville]

i have a 96 chevy pickup 5.0 liter and the check the engine light came on and was flashing and it was missing.i have a buddy that does a little work on the side he hooked it up to his scanner and it said multipe miss fire cyl 4.changed car roter and plugs and wires.it didnt help any ideas what it could be or where to look next?

[spearchucker]

Dirty injector.

[caseymcq]

Maybe O2 sensor. I have an '04, it has 4 O2 sensors. I have replace 2 of them. It ran really crummy, got bad gas milage and seemed to miss fire when they were bad. I think the bad O2 sensor can cause the fuel/air ratio to be way out of wack causing the missfire.

May be best to bring it in to a professional. Might actually save you some money if it is someone who can get right to the problem rather than trial and error.

[Jeremy airjer W]

So it was a code P0300 and a P0304 or just a P0304. The codes present are very important to send you in the right direction. If there is just a code for the one cylinder than I would be checking compression and the integrity of the injector on that sensor.

If there is a code P0300 than I would be looking into other sources that would cause missfires on all the cylinders. Things like vacuum leaks, extreme lean, extreme rich, weak spark, low fuel pressure, etc.....

[Double D]

Are there coil packs on an engine like that? That was the problem with mine.

DD

[ortonville]

it ended up beind a bad injector