P0302 and P0325, 1997 Nisson Pathfinder

Codes: P0302 (missfire on #2 cylinder) and P0325 (knock sensor)

Vehicle: 1997 Nisson Pathfinder, 4wd, 3.3 liter V6, Automatic tranny,A/C, 162,000 miles, with a pair of fussy dice over the rear view mirror.

Problem: engine fully warmed up - shut off for say 5 -60 minutes - then the warm restart results in a missing (presumably on #2) which goes away after 20 - 120 seconds - then it runs fine. Cold starts are AOK.

Plugs, plug wires, distributor cap and rotor are fine. No engine coolant leak.

My guess is that the fuel injector for #2 is bad and that is setting off the knock sensor. Am I right on or ----- ?

The #2 injector is hard to get to, being under the upper intake manifold. But, it is the first one on that side and it looks as if it could be replaced without removing the upper intake manifold (removing the distributor cap and maybe the whole distributor to gain better access). Is this possible or is that just wishful thinking?

Thanks for any help!!
Ray Fowler

wrong forum ray!

Moved to P0XXX

It sounds like the injector could be leaking and causing a hard start, then as the fuel clears up, the idle gets smoother. I'd want to take a fuel pressure leak down test and see if in fact the injector is leaking

what the heck are fussy dice? Is that a vegas thing?

To clarify: the warm starts are not "hard to". It starts fine but misses.

Yah, I misspelled fuzzy - but, they are loaded.

First step is to determine which cylinder is missing by scoping ignition and checking fuel pressure while problem occurs. Is the miss associated with blue smoke at the exhaust? If so, possibility of valve guides/seals leaking into cylinder and fouling plug until it clears itself. Leaking injector is still a possibility here as well.

That's a good thought. The fuel pressure leak down test. I will do it later.

Would a can/bottle of fuel injector cleaner (lucas brand) possibly fix the problem? (I don't have much faith in additives, but just maybe?).

Also, is it possible to remove the #2 injector from under the upper intake manifold without removing it?

Thanks!
Ray

Whether or not a bottle of injector cleaner will clear up the problem depends on what the problem is.
I don't know if you can replace the #2 injector without removing the intake plenum because I don't know what it looks like. If it looks impossible, it is.

One of the things that would affect the possibility of removing the #2 injector is its length. I feel somewhat confident that the two screws could be removed (just don't drop one) - but is there enough room to extract the injector? I guess that I'll have to measure one to know.

The engine doesn't use any more oil than it should. Also, no smoke on cold starts that would indicate worn valve guides.

You could try to remove the injector. If it's too long to be removed, then you could remove the intake plenum at that time.