Hello all,

I've recently acquired a 1989 Cherokee (4.0) from a friend, I got into this knowing it would need work but can't seem to figure out where else to go to get this fixed. I feel as if I've tried everything. It's been sitting for upwards of three years, and I was told it was running great before It sat.

My issue is I feel as if the jeep is misfiring when I'm driving. It's pretty sluggish and you can hear it struggling. I've been replacing stuff here and there that I knew would probably be needing replaced soon, but here where I'm at right now as for things replaced/changed;

• Oil changed (added oil stabilizer into it since it's been sitting for a while)
• New plugs (Gap per spec is .35 - Is there something better to run this at?)
• Plug wires
• Cap, rotor, etc
• Coolant system flush
• Throttle body cleaned

I'm not sure where else to go with the rough idling - It's not a daily driver, but would like to at least be able to take it out.

Any suggestions are much appreciated, so thanks ahead of time.

 

Congrats on the new-to-you Jeep. Head over to cruiser54.com and start going through all of his great tips, especially the ones about repairing and upgrade the ground connections. There are some tips for cleaning the ignition module and connections underneath.

Trying to think of things that would go bad sitting.... Fresh gas in it? Rodent damage to wiring, or plugged exhaust?

 

Going to do a few of his steps when I get home, have been reading a lot of them. Also going to pull cat off and see if its plugged. Thanks for the reply!

 

Mine was misfiring and running rough when warmed up around 210 degrees. A fuel pump replacement fixed mine(including pressure regulator). I know there are differences between my 1996 and your 1989, but a few things to check...

A bad fuel pump or fuel injector can definitely cause this. I'd get the fuel pressure checked.

 

I did do a fuel pressure check, and it checked out great! Also first thing I did was replace fuel filter and put fresh gas with a can of seafoam because it had been sitting for however long.

 

Did you do a compression test as well? Just to rule out a head gasket issue.

 

I haven't yet, need to replace an O ring on compression tester, will be doing that this weekend.