Renix motor swapped into a 97-issues

Hey all,

I bought a 97 XJ for $500 that was advertised as "running rough". Got down there and found out a Renix motor had been put in the place of the HO. Now, this thing runs "rough" to say the least.

-It will start but the idle RPM are all over the place
-When gas is applied, it slowly takes throttle, but sputters and coughs
-It will die after driving for any amount of time

From what I can tell, the guy used all of the correct 97+ sensors (not to say that they're all good though). The coil is mounted off of a metal bracket and it looks as though it is grounded fine. I am leaning towards one of two things. He either used the Renix flexplate so it's not timed correctly because of the CPS, or the distributor is off a tooth or more. I suppose the ports of the intake not matching the heads probably doesn't help but can't imagine it's making all of the problem. Can anyone lend me any insight? Any help is greatly appreciated.

Thanks
-Collin

Well, I would start with re-indexing the distributor first--but check and see if it is the Renix or H.O., the distributor is the same but the synch sensor isn't.

EDIT: not sure if it would even run with the wrong flexplate/crank sensor installed.

joe_peters said:

Well, I would start with re-indexing the distributor first--but check and see if it is the Renix or H.O., the distributor is the same but the synch sensor isn't.

EDIT: not sure if it would even run with the wrong flexplate/crank sensor installed.

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Thanks for the suggestion Joe, does it sound like a timing issue to you also then? And on your second thought...does anyone know if the motor would give me these symptoms with a Renix flexplate and HO CPS?

Joe_peters was right on the money about the distributor when I swapped a 97 Grand Cherokee 4.0 motor into my 97 XJ. On his advise I swapped my XJ distributor back in and reindexed it and the thing ran perfectly. It only takes a few minutes to index the distributor so I would try that advice first.

Well, it turns out the guy who put the motor in arranged all of the spark plug wires completely backwards (he thought cylinder #6 was #1, etc.). I switched them to how they were supposed to be and re-indexed the dizzy, all is fine now. Thanks for the help guys!

BIGSLVRXJ said:

Well, it turns out the guy who put the motor in arranged all of the spark plug wires completely backwards (he thought cylinder #6 was #1, etc.). I switched them to how they were supposed to be and re-indexed the dizzy, all is fine now. Thanks for the help guys!

Click to expand...

THAT is why signs like this exist:

EDIT: forget it, can't get the image to post right!

Firing order is marked on the intake manifold if you ever need it again :thumbup: 1-5-3-6-2-4. Funny that he had it completely backwards.

Too young (15), to old (36) just right (24).

Who am I kidding, at my age they look good even if they are on Medicare!