Fuel system troubleshooting recommendations?

Why do you think it's a fuel related problem? Could be, but...

What came to my mind was also a faulty CPS. When it gets hot it stops working, then cools down and works again. Could of course also be fuel related, ignition related, computer related etc...

regards Odd-Inge Larsen

I thought it was fuel system related because the 'cut out' is similar to running out of gas. It starts to sputter then gets no power at all. Then suddenly it starts running again.

Based on the seemingly high rate of failure of these devices it seems that will be a good place to start. I see that early 90's models may have problems with a low signal strength "due to a larger than desired distance to the flywheel sensing ring."

Thanks Matt Mika

Second CPS.

Fuel filter will show up as a power sag at full throttle (or even light ping) Fuel cutout will give you a bit of hiccup but the engine usually keeps on chugging along. If the fuel pump stops it generally stops, period.

The new ones come with a single hole, the old paper gasket type are no longer produced.

I have a writeup on the 93ZJ on my website.

My `89 Cherokee 4.0L did something that _sounds_ similar. I replaced the fuel filter and it seemed to clear it up -- until it flat-out died on a holiday weekend 6 miles from home in the middle of a neighborhood that looks a lot like Ramadi. The in-tank fuel pump needed replacing and when they did they had to wash a lot of crap out of the tank. Unfortunately, they didn't replace the fuel sender, so I kept running out of gas with about a 1/4 tank left and it had to go back to the shop for that. I don't know that that is what is happening to you, but if it is you might consider replacing the pump and sender while the tank is out.

IIRC, there have also been grounding issues with the fuel pump. Someone with better notes on that should pipe up and guide you on that one.

Before I posted I was thinking heat might have something to do with it, as the problem started when it started gettingwarm here in Denver. Today its in the upper 90's and when I went for lunch I drove about 10 mins. and it started acting up. Luckily I was able to get out of traffic before it totally died. I let it sit while I ate my lunch and it started right up after a 10-15 min rest.

I checked with Autozone online, they have the part for $61.99, havent checked if a location close to me has one in stock yet.

I also called Lithia, the jeep dealer by my house, and they said $127.07. Thats quite a difference.

Are aftermarket CPS's ok or should I stick with OEM?

TIA Matt Mika

I've used both OEM from

Considering your talking heat, it could also be the ignition coil. Those can also fail when hot. I had one pull that stunt on me also.

Hard to describe the difference, both feel about the same. Although the coil tends to give more grief at high rpm (providing it starts) while the CPS tends to barf when your coming to a stop. Or at least it did for me.

MattMika proclaimed:

Also check the connections to the CPS. Notorious for getting filthy and corroded. A few disconnects and connects might cure it. ... and check the engine--body ground.

Thanks to all that replied.

I replaced the CPS the day before yesterday and havent had a stall since.

Matt Mika

Thanks for letting us know.

That makes one more of a whole bunch of problems traced back to that CPS sensor.