redneckabbott

Who has done the swap successfully and what did you replace to make it work? Changed my flywheel the other day and it was trying to start but had old gas and bad plugs, fixed that and now not getting spark to the plugs and everything tests good. I'm upset! Any help appreciated!!!

winston427

The engine block is the same, but the head, intake, throttle body, sensors, and engine control system are all different. Can you get the Renix setup to work on a H.O. engine and head, yes. Will it be a well performing, efficient setup, NO. The intake and exhaust ports are shaped differently on the Renix and H.O. heads and the Renix intake does not flow well with the H.O. head. The same for the reverse setup.

redneckabbott

I shoulda posted that I got this jeep not running with this motor already in it and I'm trying to figure out why it won't run. It had a 93 model flexplate and I was told the cps couldn't read it so now that has been replaced but still not firing.

winston427

Give us more info about the vehicle you are working on. You have not given any details for us to help you. Year, engine, trans?

redneckabbott

I was told 1990 but the vin has the letter L so i'm thinkin 88. The original 4.0 was swapped for a 94 4.0 from a grand cherokee and it has an auto tranny so i'm assuming aw4. It's 4x4 if thats needed.

winston427

So would that make it a Frankenkee or a Cherokenstein. L should be a 90 model, the 88 VIN year code is a J.

redneckabbott

Ok so it is a 90 but I still need it running. My coil is reading .049 ohms and according to my book it should be like .90-1.10 ohms so I'm about to just buy one to eliminate that

Abovetimberline

You have a 90 xj and you put in a 94 4.0. You used the 90 flexplate right,all you can use from the 94 is the longblock,the controls are different. You would of had to use your distributor,so is it possible it is out of time.

redneckabbott

I got it not running with the 94 already in it but yes I swapped flexplates and then I set the timing. It will spark once at the plug and stop. It's very aggravating going behind trying to fix something somebody else couldn't!

Abovetimberline

i assume you are using the dist from the 90 also?

redneckabbott

It looks like the 90 dist

Abovetimberline

Did you install it from the 90,or did someone else,all of them look the same except 2000 and 2001,which do not have dist's. does it look like someone may have spliced the wires to fit. The 94 has a cam senor in it and the 90 does not,they are not interchangeable,but they do look alike. In 91 alot changed when chrysler took over from amc.
I have no idea of the history so lots of questions.

redneckabbott

It was already on there. It looks like a factory harness connection. Prob won't mess with it anymore til next weekend

redneckabbott

Thanks for the help. It sparking now but it's not hitting a lick trying to fire. I think its timing or fuel related.

Throttle Jockey

mine xj is a 90 as well. i got it with a 96 4.0 half way installed. i ran in to all the same problems you are. make sure all of your grounds are connected. there is a braided ground strap on the firewall just to the driver side that was left off. it took me for ever to find it but the fuel pump wont run without it.