87 comanche won't rev

I'm fixing a buddies 87 comanche 4.0 with a stick shift. He just put in a new engine and it just doesn't run right. The EGR got trashed and capped, the vaccum lines are new, the O2 sensor is a new unit as well. We are in the process of getting new TB sensors, both, and a new knock sensor. It looks like a timing issue, just can't find how to adjust the timing on this thing. Give it a poke on the go pedal and it sputters, go slow and it's fine. Go past 3500RPM and you've got yourself enough pops for it to be the 4th of july... Man, I'm out of ideas on this one, anybody got an idea where to start?

Phil :canada:

what did the new engine come out of? do you have the haynes manual or fsm? :read:
both books should tell ya how to do the timing.

recalibrate the computer? check the fuel pressure? plugs getting too much/not enough spark?

I would almost guarantee it's a CPS problem. Did he get the CPS seated all the way when he was renistalling it? That's a good thing to check. I've gotten them set in there off before and it's knocked that magneto deal off the end of it and done very similar symptoms to that.

Ok, no laughing, what's a CPS? I'm a VW mech, these jeeps are new to me...

Phil :canada:

Crank Position Sensor = CPS. on the back of the enginge on the drivers side just above the bellhousing. got 3 wires on it. a buddy replaced mine for me while i was at work.

Crank Position Sensor = CPS.

its located on the rear of the engine above the bellhousing on the drivers side.
be carefull removing the 2 bolts holding it on, do not drop them into the bellhousing.
also it has 3 wires going to it.

Right on, thanks.

party1:

It's actually in the bell housing, upper drivers side corner. What year was the donor engine out of? If it wasn't another Renix era XJ, then you needed to swap over the flywheel as the teeth changed when Jeep went to the HO setup. Throttle position sensor would be different too. Got the plug wires on right?

Oh, and you can't adjust the timing.

Your problem is VERY simple.

the distributor is off by one tooth.


on those motors, the timing is controlled by the ECU, the distributor MUST be aligned exactly with the right tooth or else it'll do EXACTLY what you describe.

Roger that, will be checking ALL these to make sure I don't screw this up.

Phil

you guys rock.:guitar: