I have a 97 Mitsu Montero Sport, XLS, 3.0L, V6 4x4. It is running really rough. I have changed the oil, oil filter, spark plugs, wires, air filter, fuel filter and 2 fuel injectors. One of the spark plugs keeps getting soaked in fuel and can't fire. I have driven for a few miles and the check engine light does NOT come on, so I can't pull any codes. I did try a compression check and it appears ok. I just bought the vehicle and it looks like it had sat for awhile without being driven. I bought it cheap not running. Got it to start and run, but runs really rough.... ANY ideas?

 

Do you have spark at the cylinder thats fouling the plug out?

 

Yes, I have checked for spark on all 6. They all spark just fine...

 

Did you check to see if the fuel injector is stuck open?

 

How would you check that?

 

I have become a pro at taking the intake off the vehicle since I've done it like 6 times now, Do you check for a injector stuck open with a NOIDS light kit? Can you test with that when you have the intake off? I guess just stick them on there and have someone turn the ignition for a few sec and watch the lights?


Other things I have done: I drained the fuel and refilled with chevron supreme. And the computer looks pretty new and shiny so I think it might have been replaced sometime previously. but i smelled around it and did not smell anything fishy or otherwise.

The cyl's that are not firing are the rear two on driver side. I have been checking which cyls are not firing by pulling the plug wire at the coil pack with insulated pliers, and listen for engine idle decrease. When I do this the coil pack arcs like crazy trying to find the plug wire, is this the best way to determine which is not firing?



Thanks for any help you guys can give!!!

 

A noid light wont tell you if the injector is sticking mechanically, It just tells you its getting power to fire.

Try swaping out an injector w/ another cylinder and see if that plug gets fouled out.

 

Figured it out. Apparently, someone tried to work on it before I bought it. They crossed the 2 wires of the plugs that weren't firing. I tried switching them just on a whim and now it runs awesome! After 4 days of working on it, it turns out it was a 2 second fix....

 

Thats good you figured it out. Its weird that the cel didn't come on.