pulled the plug wire still runs the same

[jrskaggs79]

pulled the plug wire still running?

I have a 90 2.9 it runs really rough but will idle in park. I tested. Coil wire and plug w meter all good. Truck was running i took off #6 cyl wire and it didnt miss a beat. Any help eld b appreciated

 

[adsm08]

If pulling #6 didn't change anything you probably have a miss on 6.

Have you checked or changed your plugs lately? Even a good mis-gapped spark plug can cause a miss.

Also good to check spark on the suspect cylinder.

 

[jrskaggs79]

Getting fire...at plug over 12 volts

 

[tmcalavy]

Do a spark and compression check on all cylinders. Is No. 6 firing all the time? Maybe, maybe not.

 

[jrskaggs79]

Compresion is even on all cylinders. Could it be the FPR or the ECM?

 

[jrskaggs79]

I have a 90 2.9 it runs really rough but will idle in park. I tested. Coil wire and plug w meter all good. Truck was running i took off #6 cyl wire and it didnt miss a beat. I alsio checked the compression it was even on all the cylinders. Any help would b appreciated

 

[ab_slack]

If pulling the wire on any other cylinder besides that one makes it work, it seems that be the problem cylinder.

If that is causing the miss I would first think bad plug or wire but it may be worth checking in the distributor cap for dirt or anything odd around that cylinder's wire.

If not spark, then the fuel injector for the cylinder. That could be the control signal to it or it could be the injector itself.

 

[shane96ranger]

Getting fire...at plug over 12 volts

Uh yeah... you should be getting something to the tune of 30,000 volts at the spark plug. Was that what you meant by "plug"?