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[Chsrles]

I have a 1989 Jeep Comanche that I bought about a year ago and it has not ran right since. It’s an 89 with a 96 motor adapted to the renix system. Tons of new parts from previous owner and yes he swapped everything over properly. My dad Uncle brother and I have gone through everything. It has been to 2 shops and nobody can figure it out. The truck runs super rich and runs rough. Would love to hear any ideas or thoughts? Would also like insight on converting to carbureted and how to go about that. Carbureted is a last resort of course but after a year, I’m ready to drive it.

[eaglescout526]

Which engine?

[Eagle_SX4]

The oxygen sensors are getting hard to find for the Renix system. Several people have had them not work right out of the box. I would start with that.

[Chsrles]

5 hours ago, eaglescout526 said:

Which engine?

4.0

[DirtyComanche]

Back up to what was swapped over.  

 

And did it run right before the swap?

[Chsrles]

Not sure I wasn’t the one that did the swap the previous owner did and showed me pictures and videos of everything he did. He said it ran like a top the week before I purchased it it.

[DirtyComanche]

If it ran nice before (do you trust him saying that?), then I'd start by checking the CTS, IAT, MAP, O2 for being ballpark right.  I'd then check fuel pressure.  If they all check out I'd pull the fuel rail and see if the injectors are dribbling.

 

Is my troubleshooting the best?  No.  But it's what I'd do.

[pizzaman09]

Also check that the manifold header bolts are tight and all are present.  This can cause all sorts of poor running that manifests itself as an incorrect fuelling issue.