We are currently having issues with the start up for our '93. When we turn the key to crank, it takes longer than it usually would, and as the days go by, it takes longer. We initially researched what the issue could stem from, and found what's call a "Poor Man's Prime." We did this and she started up like how she's supposed to. The fuel pump was replaced sometime in spring-summer '23 by the previous owner however, we don't know the brand, etc. We are also not sure where to start with a diagnosis.

Some other issues of concern would have to be our overheating issues. While driving/idling, the gauge would sky rocket to the red after about only 5 minutes. I'm not sure how serious of a repair for this would be, but it definitely gives us a scare. After about a half of a hours worth of driving, she starts to idle at 2000 rpms. If anyone has any insight on how to go about solving these problems, please let us know.

 

Get a decent scan tool, knowledge is critical. Check your fuel pressure, should not have to prime at all. See if it holds pressure after motor is off.

 

Pull off the fuel pressure regulator vacuum line and prime the rail (on off, etc), if it leaks gas out or smells of fuel around it, its failed. If not I would bet that the inner o-ring on your fuel pressure regulator is rock hard and leaking by. Try pulling it off and replacing the inner o-ring with a nitrile rubber one, if that doesn't work, the cheap ones on fleabay work fine.

these old jeeps don't like ethanol fuel and most of the rubber used that comes into contact with it either melts away or gets rock hard and leaks.

See: https://www.cherokeeforum.com/f2/bad...gulator-274531

For my recent adventure here