I have a 1997 xj country edition, 177000 miles. When I start it up on a cold start it will misfire until I start goin down the road, it will usually even out once I hit 2100rpm's in 2nd gear. It was throwing a p0205, p0305, and p302 codes. The p0205 code is for an open injector 5, although cylinder 2 is the one misfiring on startup. I replaced injector 2, spark plugs, wires, distributer cap and rotor, and tps and it is still misfiring.. The misfire is coming more and more frequent now misfiring sometimes on a hot engine after running into the store or something. I don't know what else to do, anybody have this same problem or know how to help?

 

Are you having to add coolant to the reservoir?

 

No not that much anyway.. I have a small leak on one of my freeze plugs that I'm planning on fixing this summer. I bought it that way last summer.. I have to top off the coolant pry once a month or two.. I don't have my electric fan on there right now tho, the bolts broke when I put in a new radiator this winter, would that make such a difference i would be getting heat soak?

 

So, it appears that you have two cyls misfiring, one due to an injector issue. Is that right?

Your Jeep is affected by the valve spring TSB, which basically says that if no other causes can be found for a misfire, you are to run Mopar Combustion Chamber Cleaner and replace your valve springs with the current part number. It fixed a #1 cyl misfire on mine.

 

I don't think I'm ready to start changing valve springs quite yet. When it's misfiring I unplugged the cable to each injector to find out which cylinder is misfiring, cylinder 2 is the only one that misfires on startup, i have made sure multiple times. What boggles me is how it evens out once I start going and then runs perfectly fine. I have a feeling it might be a faulty sensor or something.

 

If you are having to add more coolant than the freeze plug is weeping, you may have the start of a blowing head gasket.

 

You might have a weeping injector flooding your no.2 cyl causing rough idle at start up. Swap the location of the injectors and see if the misfire follows.

 

+1 to this.

 

A sensor would not affect one cyl only.

 

I have also already tried swapping the injectors, i forgot to mention that. Could this also be a wiring problem?