I have an 89 XJ that up until a couple weeks ago ran perfectly fine. Then I had a day when it wouldn't start. I tried starter fluid with no luck. I killed the battery and boosted and still no fire, then finally, it caught, and it still ran fine. Then I noticed I had blown a leak in the rad. Got some pellet stuff, put it in the top hose for the rad and ran it for a while- ran fine, fixed leaking hole. Now I had someone come test drive it a couple days ago, and during the test drive, it starts surging and sputtering and not responding to the gas pedal. NOW...its a PITA to start, and when it does, it idles like crap, backfires, surges up to about 2500 rpm, then stalls. If I touch the gas pedal at all, it stumbles, then revs up AFTER I take my foot off the pedal.
I'm trying to sell this, so I'm not wanting to put a ton of money into it just so I can sell it. I already replaced the fuel filter.