Mechanics

GMC JIMMY FUEL PUMP PROBLEM

1993 GMC Jimmy

My 1993 gmc jimmy, which has over 177,000 miles and is a 4wd with a 4.3 liter engine, has been, increasingly now, failing to start again after it has been driven recently. For example, I can go out in the a.M. And drive to work, but, if I should want to drive it again after a few minutes or even a couple of hours it will crank just fine but won't turn over. This would only occur once in a great while (once a month for example). However, it has now, as of recent, begun to stall and surge while driving.

I had this diagnosed by mechanics and they detected fuel leaking down onto the plennum cover which was resulting in a somewhat of a " flooding" manner and would then require time to " dry out" (approximately 24 hr.). I also heard from another mechanic about how the spider assembly - fuel-injection unit can begin to develop very fine hair-line cracks in the fuel injectors and this can result in a similar problem as the aforementioned suspected cause. In addition, another mechanic had suspected it may just be a bad fuel pump needing to be replaced. My dilemma of course is wanting to know what is the MOST likely cause of the symptoms I'm experiencing? Your input would be greatly appreciated!



Sincerely,

Kevin Neslund
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Kevinneslund
April 24, 2007.



Could be any of the above. But usually with the fuel regulator or injectors leaking you get rough running when it does start.I have seen the pulse dampener on the fuel pump do exactly what you are describing. It (dampener) is a black plastic piece inline betwwen the fuel pump and the assembly it mounts on. It was designed to calm the pulses created by the fuel pump, but over time causes hard starting, surging, and overall lack of performance. At the year and mileage of your truck I would do a fuel pump just to be safe. The A/C Delco pumps come with a piece of injection hose to eliminate the dampener

Tiny
Jack42
Apr 24, 2007.