MisFire Issue ??

[Torqueranger]

I have a 98 Explorer 4.0L Sohc...
I keep getting a misfire on cylinder 2 and 5 and no a misfire on multi cylinders ...
It was ok before but I change the Pvc ,spark plugs and wires and still not running right and now get misfire codes ... I changed the coil pack and tps sensor and still runs bad and still codes ..
The original plugs were autolite Single Platinum with cheap wires and I was not getting any codes with this setup but It had bad gas mileage and running rough but no codes...
Any thoughts ??? O it has a new fuel pump and filter ..

 

[rb142]

My first reaction with that combination is the coil pack -- which you said you changed. I'd still give it a good, hard look. Have you verified that you are getting (or not) spark on those cylinders? There could be a problem with the power or driver signals to that coil that is preventing it from working, even if the coil and wires are good.

If the ignition proves out, all you can do is to go back to basics: air, fuel, compression. Not too many things will affect those two cylinders evenly though. Possibly a vacuum leak. Are the injectors working right? Could be a lot of things. I assume you are saying that you have P0302 and P0305 but not P0316, right? (BTW, 316 is not multi-cylinder, but random cylinder ... meaning that it is moving around and/or that it doesn't know which cylinder it is). Do you have any other codes? If you have a scan tool, watch the fuel trims and the oxygen sensors for clues.

Start simple and follow the trail until you find something.

 

[2000StreetRod]

check wiring

Especially cylinders 5 and 6.