COIL PACK NOT FIRING ON #2 AND #3

[deltas69]

Been chasing a miss on my '94 2.3 5 speed 2wd Ranger. 137K on the truck..have narrowed it down to front coil pack not firing on #2 and #3..replacing the coil pack with a new one did not fix it...Plugs, wires, IACV replaced..throttle body cleaned as well as the MAF sensor...I drive it 200 miles per day..and it runs fairly well at 70 to 75 mph..but I can tell it has the miss..any ideas where to look ?? tia..pj

 

[gmtmvt]

Just lettin you know we have the same proplem. Different a bit, because the secondary isnt giving any spark to any of the four plugs. It runs fine on the primary. we are still shooting wires righr now. let you know though. we do have power to the red wire though.

 

[RonD]

1989 - 1994 2.3l use an ICM(ignition control module) located on the front of lower intake manifold
These were a know issue, they can be tested but often it was brittle wires and connectors that were the problems
Also they would lose Grounding, which is done but screws holding it to intake.

There are 2 coils in each of the coil packs, 1/4 coil, and 2/3 coil
They can be wired 4/1 and 3/2 doesn't matter, it one coil firing 2 spark plugs at the same time

Each coil pack gets 12volts on the Red wire with key on
Other 2 wires are Grounds, one for each coil in the pack
A coil is grounded to "power it up", when the Ground is cut the coil releases the high voltage "spark" energy
Then its grounded again to power up again

So your ICM is not grounding or ungrounding that one coil, check that wire back to ICM

 

[gmtmvt]

thanks for the info, I chased more wires, checked all the grounds going to the pCM, ( the '99 sends its sigals to the coil packs dirrectly through the PCM.), all the signal wires and grounds have continuity. I'm starting to think that the PCM isnt sending any signal to the secondary. I cant seem to find anything on it in google searches.

 

[RonD]

Sorry this is what I read: "Been chasing a miss on my '94 2.3 5 speed 2wd Ranger."

Yes, 1999 is a different system

If you have swapped coil packs and the same side still doesn't work then yes, most likely PCM