'96 Hombre 2.2L P0301

[tV8bird]

Hey, guys.

Hoping for a little info for a buddy. He has a 1996 Isuzu Hombre 2.2L, vin 4.

We're having a lot of trouble finding information on his present problem: cylinder 1 misfiring under a load. The only code that comes up (and intermittently, the MIL goes out) is P0301, misfire cylinder 1.

• 
  We've done a compression test on the cylinder: good
  He tested the coil packs: good
  We can't test the fuel pump pressure in the fuel line because there's no place to put a gauge.....?!?!?!?!?!?!
  He changed plugs & wires
  He tested power going to the injectors: good
  He changed the camshaft pos. sensor

The engine still misfires under a load. Thoughts? Help? Ideas who to turn to?

Thanks, guys.

 

[Vanimal]

clogged injector?

 

[MoparManiac]

I know it's only happening on one cylinder (so says the computer) but changing the fuel filter I'd imagine is cheap/easy enough.

Assuming there's an external/inline one.

 

[sandsgg]

Have you checked the s10 forums?

 

[tV8bird]

Have you checked the s10 forums?

Yeah, you'd be surprised how little help they are...

...these trucks are bizarre. The 2.2L I4 has many little variations, and they don't have anything to do with it being a Hombre or an S-10 or a Sonoma. I think it's maybe mid-year changes.

Anyway, the guys in the S-10 forums who solved this all changed parts we've already ruled out. I thought I'd try in here because it doesn't cost anything...nothing to lose!

 

[tV8bird]

I know it's only happening on one cylinder (so says the computer) but changing the fuel filter I'd imagine is cheap/easy enough.

Assuming there's an external/inline one.

There is...

My concern is exactly what you pointed out--is it possible to miss on more than one cylinder, and only get a 301? I guess it is, so I should be asking, Is it likely?

I hate computerized systems; I feel like we put too much trust in them.

 

[tV8bird]

Nevermind, it's the coil pack.

Found out that testing without testing under load didn't prove anything. Followed someone's instructions in another forum, and switched the 1&4 plug wires at the plugs, and it threw a P0304 instead.

Happy day.