Help please. I am working on a 91 2wd Comanche. It originally had a 4.0 which died. The owner (who I am doing a favor for by trying to get it running) had a 94 4.0 swapped in. long story but after installing the CPS, reinstalling the distributor (TDC #1 twice at 1 and 2 crank revolutions couldn't determine compression stroke from under truck while turning crank) and correcting miswired distributor it still won't start. Had no fuel in it to start. Fresh fuel and filter, pump cycles, plugs smell like gas. Have not checked spark yet ( will borrow plug tester tomorrow).
Anyway is all this effort futile with a 91 ECU trying to run a 94 motor.
This truck has not run in 4 years and I was not involved in the swap so I am doing my best with this puzzle and my limited knowledge.

 

How did you install dist with out knowing when it was tdc on compression stroke ?

 

I put the notch on the crank pulley at the "0" mark on the timing chain cover. Set the distributor to point at the number1 spark plug wire/nub. However I could not crank it by hand and put my finger over the cylinder to feel for compression at the same time. SO I tried starting it unsuccessfully, turned the crank 360 and tried starting again neither worked.
I checked for spark today with an inline spark tester. No spark at all.
On a non computer car I would consider the coil as the culprit (or possibly some wiring dilemma.) But I don't want to just throw parts at it.

 

No spark sounds like crank sensor, dist point a little after no 1 not directly at it .

 

Thanks. Is it possible that the 91 ECM on the car is not reading the Crank sensor? The sensor is new. I put it on myself. Is there any adjustment to the sensor could I have installed it improperly? It only seemed to go on one way.

 

Where did you buy the crank sensor? Autozone?

You can see if the PCM is reading the CKP properly by checking if it energizes the ASD relay under the hood. I don't have any diagrams for 1991 so you'll need to probe it with a multimeter. One of the sockets should light up during cranking.

 

Which year sensor u using ?

 

what flywheel if it has the 94 it will never run

 

91 and up all the same. Theres only been 1 confirmed 91 renix Ive ever seen.

 

When did odb2 start ?

 

shoot my bad was thinking renix to obd1
think obd2 was 96

 

That's what I think also 96....

 

Yeah 96 was the first OBD-II. 91-95 PCMs should be compatible... Same sensors

 

OK. I guess I have several things to check.
I am not certain but the CPS probably came from Advance Auto. It is a 91 CPS according to the owner.
I do not know what year the flywheel is. probably the 94 as it would have been easier.
I had looked up computer compatability on a jeep forum prior to posting this thread which is why I suspected the computer as the culprit. According to that post 91-92 interchange,93 stands alone, and 94-96 interchange. So the flywheel kind of makes sense.
I am doing this as a favor for someone ( as in free, so I am not going to throw money at it) and do not feel any sense of urgency other than getting it out of my driveway as it has not been running for 4 years or so.
ANy idea what a rust free, 2 wd non-running, 4 liter, 91 Comanche Pioneer is worth?