2002 Express LT(5.7/4L60E) tricky problem stalling only on long duration trips
September 1st, 2017, 9:18 AM
#11
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Performed a leak down test. 60 psi or so with ignition on. 52 psi running and loses 5 psi in the first several minutes after cutting off. I let it idle for 4 hours with it 75° to attempt to duplicate syptoms and it runs perfectly. Has to be hot out and has to be driven apparently.
Last edited by brandonguinn; September 2nd, 2017 at 7:53 AM.
September 6th, 2017, 5:09 PM
#12
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Latest test of the pump directly at the filter is 75 psi. Still haven't found the problem but the only clue may be low fuel pressure at the rail. 51-52 idling and 59-60 at WOT. Never gets lower than 49 on downshifting to decelerate. All these numbers seem low? Not sure how it would only cause stalling on hot days and long trips.
September 13th, 2017, 1:44 PM
#13
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Blocked the fuel return and the rail pressure climbed into the 60s. Going to replace the fuel pressure regulator and upgrade the spider to the MFI system. Hopefully this solves it.
July 2nd, 2018, 3:02 PM
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I figured. I was stranded on the side of the road 5 hours from home with all my kids in the car. Pretty much at the mercy of a dealership that was nearby. I wanted to have some kind of grasp of the situation and avoid any “guessing” that’ll cost me $$$ without fixing the real issue (which would just leave me stuck again 2 hours down the road).
This mom (and her 4 kids stranded on their road trip) are very grateful to the posters in this thread who took the time to write. Sure helped me feel less desperate and clueless in the middle of a pretty unpleasant situation.
Hoping the dealer’s fix (new fuel pump) takes care of the issue and we will be on our way. *fingers crossed*
Thank you all!
This mom (and her 4 kids stranded on their road trip) are very grateful to the posters in this thread who took the time to write. Sure helped me feel less desperate and clueless in the middle of a pretty unpleasant situation.
Hoping the dealer’s fix (new fuel pump) takes care of the issue and we will be on our way. *fingers crossed*
Thank you all!
July 3rd, 2018, 7:10 AM
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I replaced the spider assembly and that wasnt the problem. I pulled the fuel pump. The fuel pump they used was from O'Reilly (looking it up from the numbers). Many have had oroblems with this, and all, non delco pumps. My guess is the pump didn't provide enough volume as I haven't had the symptom again. The real test will be in the next week, now that's it's hot, I'm going on the first real long drive.
July 3rd, 2018, 10:47 AM
#18
A fuel volume issue would only cause laggging on acceleration. Like when the secondaries open on a carb it bucks and when you back off on the throttle it smooths out. I had that once due to a bad fuel filter restricting fuel flow. Pressure was fine....
Bogging down and stalling outright is more of a fuel mixture issue. Its riching or leaning out.
That is hard to find without codes.
Did you replace that bad cat? The o2 sensors must be getting the right readings or fuel system issues follow. (o2 sensors need to working right as well)
Had held code readers dont always fine everything. Sometimes you need a big shop machine.
Being a Jasper engine, is there a factory sensor missing??
Bogging down and stalling outright is more of a fuel mixture issue. Its riching or leaning out.
That is hard to find without codes.
Did you replace that bad cat? The o2 sensors must be getting the right readings or fuel system issues follow. (o2 sensors need to working right as well)
Had held code readers dont always fine everything. Sometimes you need a big shop machine.
Being a Jasper engine, is there a factory sensor missing??