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-   -   Fuel Pump Overheating?? (http://www.jeepgarage.org/f51/fuel-pump-overheating-62665.html)

romac 07-10-2013 11:08 PM

Fuel Pump Overheating??
 
Hi fellow Jeep owners,

I have a '99 GC Laredo 4.0L that began stalling after driving 100+ miles.
No check engine light, engine just shuts off. After pulling off to the side of the road, I had it towed to a repair shop 1/2 mile up the street. The guys checked the fuel pressure and checked OK. Sprayed starting fluid in throttle body and told me it was the fuel pump. They "warned" me that it could me down the road 5 miles or 500. I drove about 10 miles and stalled again. Let it cool down for about 40 mins. and tried starting again and fired right up.
Drove about 8 miles and stalled......the stalling and cooling off continued for about 20 miles/3 hours. It was in the middle of the day in 95 degrees of hot Florida sunshine. FINALLY about an hour after the sun set and stalled on the side of the interstate in the dark. I cranked it up again and drove the remaining 80 miles home with no problem.
Could the fuel pump be at fault or could it be a clogged filter????
Thanks in advance!

Frango100 07-11-2013 07:36 AM

Re: Fuel Pump Overheating??
 
Welcome to the garage.
The mechanic checked the fuel pressure, which was ok, but still blames the fuel pump. Was there any moment during the tests that the fuel pressure was low?
Depending on the amount of fuel in the tank, the pump sits in the fuel, so wonīt get hot. Could be that it has some internal problem and just shuts off, but normally when a fuel pump stops it wonīt work anymore. I wonīt expect a clogged filter, because then the pressure should be low and/or the problem should be constantly.
So i donīt know what tests the mechanic did more to be sure that the fuel pump is the culprit, because also a crank or cam sensor could let the engine die suddenly.
Eventhough there is no check engine light, did he check for eventual set faults?
You could check this yourself doing the key dance: ignition switch off/on three times and leave it in on at the third time. The odometer will show DONE when all ok, or any fault code. Normally a faulty cam or crank sensor will set a fault code, but not always.
To replace the fuel pump, the fuel tank has to be lowered, which is a quite extensive job.

romac 07-11-2013 08:16 AM

Re: Fuel Pump Overheating??
 
Thanks for the reply Frank.......The mechanic just did a quick pressure check and saw that it checked OK, then sprayed the starting fluid into the throttle body and sent me on my way with only a warning. He knew that I had a long way to go to get home. The "jolting" and split second stall began with a 1/4 of tank of gas. After gradually making my way down the road to the closest gas station, I filled the tank and after that I made it about 21 miles before it stalled again. Coincidence? Before the full tank, I was only making it about 5 miles or less between stalls. What puzzles me is....why did it run just fine (no rough idle, no check engine light, starts right up) after the sun went down and the roads had time to cool off? It must be something heat related because I've taken business road trips of 200+ miles in the pouring rain and it drove just fine.
For the record.......I'm replacing the fuel filter today. Got to start somewhere, right?

romac 07-11-2013 08:52 AM

Re: Fuel Pump Overheating??
 
***UPDATE****

Hello Frank,

I did do the key dance on my GC and I am getting a P0320 (CKP Sensor). I'm hoping that this could point me in the right direction.....Now, could this be a heat related malfunction?
Just backed up the jeep into the garage and IT STALLED! But started right back up.

Any information is greatly appreciated.

Frango100 07-11-2013 11:49 AM

Re: Fuel Pump Overheating??
 
Yes, many times problems with these sensors start with this. I donīt know why, but after they get older heat can let them fail. I had it happen to an other vehicle i owned and it stalled after letting sit for some minutes when hot and trying to start.
If you want to change the sensor yourself then is here a writeup from jeepme: http://www.jeepgarage.org/f204/how-t...sor-51503.html

lstowell 07-11-2013 12:13 PM

Re: Fuel Pump Overheating??
 
Quote:

Originally Posted by Frango100 (Post 856534)
Yes, many times problems with these sensors start with this. I donīt know why, but after they get older heat can let them fail. I had it happen to an other vehicle i owned and it stalled after letting sit for some minutes when hot and trying to start.
If you want to change the sensor yourself then is here a writeup from jeepme: http://www.jeepgarage.org/f204/how-t...sor-51503.html

The CPS makes more sense from the symptoms given.
I'd either invest in a set of good walking shoes or get it fixed soon.

There is a possibility that it is just the connector on the thing has gotten all crudded up if you drive in muck much, but they aren't that expensive so by the time you crawl under there to clean it, you could have installed a new one.

I suspect they are made by Lucas, judging from the ones on the old ZJs.

romac 07-11-2013 09:05 PM

Re: Fuel Pump Overheating??
 
First of all.........Thanks to all replies. Especially you Frank!
Wanted to give everyone the latest.
I did purchase a CPS today ($35 @ Advance Auto) and installed with ease.
I was pleasantly surprised how easy it was to replace.
Did key dance and no fault codes displayed.
I think I got!
Will test tomorrow by doing a few short distant drives locally in the hot Florida sun.

Thanks Again Fellas !!

Frango100 07-11-2013 09:33 PM

Re: Fuel Pump Overheating??
 
Ok, good to hear. Let us know after some test driving how it went.


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