chasing a misfire

[Powder]

At low rpms and idling, Im running on 5 cylinders. Above 55mph or restarting the car after sitting for awhile at operating temp. it will smooth out for awhile. I've seen similar posts before and have changed out the same items: plugs, coilpack, module,wires, everything in the fuel system is new, O2 sensor(cc's seem normal), what's next? Right now it is a garage queen and is only driven to test a new component. Anybody been thru this or have an idea what's wrong? Thanks for any and all advice.

MLH

 

[Turbosix6]

Make sure your injectors are new and have your coil pack w/module tested.

 

[Russ Merritt]

Do a compression test, check the injector harness by unpluging each one while it's running. That might help you figure out which injector is the one. I'm betting injectors too.

 

[6SENSE]

Originally posted by Powder
At low rpms and idling, Im running on 5 cylinders. Above 55mph or restarting the car after sitting for awhile at operating temp. it will smooth out for awhile.

Sounds a little familiar. How do you know youre only running on 5 cyl's?

 

[Powder]

The miss while idling is not that bad. When you put it in gear it runs much rougher and has no power until you get it going fast enough for the engine to smooth out. The injectors, pump, fpr, filter, all have about 200 easy miles on them. Fuel press. is set at 43 with line off. I'll try pulling inj. wires just to be sure. Thanks for the help.

MLH

 

[Russ Merritt]

Hows your camshaft?

 

[Powder]

Coilpack and module were replaced separately with no effect on the problem.

 

[Powder]

You guys that diagnosed a fuel injector were spot on!! I obviously disturbed/damaged the connection to the injector harness when I did the vac brake conversion recently.

Thanks for the all the help.

MLH

 

[Russ Merritt]

VICTORY IS OURS!!!!!!!!!!!!!!!