[Ulenran]

Hi all, like the title says I have a misfire. Vehicle is an 1993 Isuzu Rodeo w/ 3.2l v6 5spd trans, with 224000 miles. Only occurs when engine has reached operating temp, and it is pretty consistent. Just replaced plugs and wires with double Platinum NGKs and NGK wires, thinking that old ones were shot. Engine sounds better, but same misfire is there. Can hear it real well standing outside the vehicle through the exhaust. Sounds like 2 cylinders misfiring one after another, but only every other revolution. I'm thinking an issue in the fuel system or coil. Thanks in advance!

 

[Ulenran]

Sorry it has taken so long to reply, other cars demanded attention....

So I got the coils replaced (the zu does start MUCH easier) but the same exact misfire is still there. I have also started getting a CEL only while accelerator is pushed while driving after warm-up. The RPMs do surge when coming to a complete stop. Again, this only happens when engine is hot and after driving for at least a few miles.

 

[Ulenran]

Fuel pump ended up dying, replaced it and the filter. Engine is happy with the fuel pressure back where it should be, but misfire at idle is much worse than ever. I still do not detect any sort of misfire while accelerating or driving. Going to check coils, plugs again (all replaced spring 22), and the EGR tube and diaphragm. Checked for vacuum leaks at hot and cold temps with a propane torch and no change in RPMs.