i have a 89 3.o v6 and i am having problems getting it to run on all six cylinders. i have 150psi of compression,good spark,and good injector pulse. i swaped 5and 6 injectors with 1 and 2 to see if the problem would follow it did not. when it runs for a bit you can pull the plugs out of 5 and 6 cyl. and they are black with carbon. i am stumped not sure how to get 5 and 6 back firing.

 

www.ncttora.com/fsm

:wabbit2:

 

Check for spark on plugs 5 & 6.

You've ruled out injectors & have good (if low) compression, so it's got to be spark related.

Was compression check with engine warm, all spark plugs out, wide open throttle, & VAFM disconnected per the FSM?

 

I have good spark at the sparkplugs. I did the compression check with them all out. Also a running compression check. Could it be something in the valve train.

 

Injectors?

 

Valve train issues would show up in the compression, so I doubt it.

^^This is more likely.

 

How did you check for spark? Did you look at it or did you use something like this?
http://www.sears.com/shc/s/p_10153_12605_SPM6522673507P