Random Stall - 1998 XJ Sport 5spd
 

For a 1998 XJ Sport 5spd: runs great for weeks on end, and then with no warning whatsoever, engine shuts off; takes 4-5 minutes of attempted restarts to get going again, then runs fine for weeks. No correlation to weather conditions or outside air temp; has happened three times at very low speed (10mph) or waiting at traffic lights, once at 30mph on secondary road

no codes; mechanic replaced CPS a month ago and just stalled out at red light today with absolutely no warning; took 5 minutes to restart, then ran fine

I've done a lot of searching and am anticipating a protracted issue with this beloved beach vehicle of mine. Could be wiring, torx screws on PCM, or any one of a number of other sensors. I could spend hundreds of hard-earned dollars and still not get to the bottom of this issue.

Do I need to junk this otherwise amazing truck that has seen more beach miles than those on the road?

Suggestions? Thoughts??

Your input is much appreciated. Thanks.

Start by cleaning up and tightening up all your grounds and battery cables. Don't forget the grounds in the trunk, driver side behind the trim panel.

Please elaborate on what you mean by "takes 5 minutes to start". The more details about what exactly is happening, is it cranking but won't fire, is it completely dead when you turn the key.. all that stuff is important.

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I did a spark plug mod some years back that wasn't compatible and it kept shutting off mid drive. I tossed the plugs but still had problems starting and sometimes it would stumble. I replaced the TPS within half an hour and the problem was gone. It was toe original TPS in my 98 from years ago on my first XJ when I replaced the TPS thinking I had a problem there and I didn't.

I don't think your problem is related but... if you just happened to put Pulstar plugs in there, toss'em ASAP.

If it takes 5 minutes of starting you're murdering your battery and wet-fouling your spark plugs. It's a miracle it even starts if it does unless you have no fuel pressure (that's what I would guess is your issue is, I've had to replace fuel pumps on every Jeep I've had). If you replace the pump, avoid Airtex like the plague. Go to NAPA and get a Bosch. Airtex will fail, fast. They're made in Mexico and they won't give you your money back at the parts store. They'll let you swap it, so now you're putting in another POS fuel pump and it's not a fun job to be doing once a month, especially when it leaves you stranded some where each time. I think every one of those pumps should be bulldozed into a landfill and set fire to.

Pat Henry: in response to your suggestion of more info - the engine will turn over but not "catch." After about 5 minutes, perhaps less time, of maybe 4 or 5 attempted starts, the engine will finally catch and we're ready to roll. When I say catch I do not mean to imply that this is like a starter not catching. The engine sounds like it wants to start but will not.

To use your term: it is cranking but will not start. It is not completely dead by any means.

I hope this provides some added insight. Thanks for responding.

I had sort of expected that was what you meant and what I was thinking might be the issue is what Commando mentioned - fuel pump.

Do the grounds, make sure to do the trunk ones since one of them is directly involved in fuel pump operation. Then I'd measure the fuel pressure and make sure you have a healthy 49psi +-5 (IIRC)

Like commando said, it is a part that fails a lot in older Jeeps.

The first time I dropped a fuel tank on a Jeep I was intimidated by the effort, but it wasn't nearly as bad or hard to do myself as I had feared. So if the pressure isn't good, it's not a death sentence for the Jeep.

Yeah, fuel pumps are expensive. Best to rule everything else out first.

An easier way to identify the fuel pump directly it is to prime the fuel pump 3 or 4 times then try to start it. Cycle the key from "Off" to the "Run" position several times, then start it. Actually, just using a fuel pressure gauge at the schrader valve on the fuel rail is the best way.

Thanks for the suggestions. I'll give those a try. Any other perspectives would be appreciated.

my jeep shared identical symptoms for several months. finally it shut off and would not restart. it turns out the coil went bad. it was a replacement coil i installed 4 yrs/90k miles ago. worth looking into.

A coil is a heck of a lot easier to replace than a fuel pump, so let's hope it's that.

The fuel pressure test and coil test should straighten it out.