Possible fuel pump going bad?
09-28-2009, 03:10 PM
#1
Possible fuel pump going bad? My car would start to stutter and pop every so often so I thought it was the opti at first. Then I was driving and about to take off and the car shut off. Tried to restart it and I couldn't hear the pump being primed like it used.
So I took another car, 3 hours later I go to start it again and I hear the pump prime and it fires right up...now did the pump overheat?
Should I just use this as an excuse like every other time to upgrade?
So I took another car, 3 hours later I go to start it again and I hear the pump prime and it fires right up...now did the pump overheat?
Should I just use this as an excuse like every other time to upgrade?
09-28-2009, 03:16 PM
#2
Before you start throwing parts at it, get a fuel pressure test gauge and verify you're getting good pressure. Should be a steady 43psi with the key on, engine off. A small amount of bleed-down is normal, but not more than one psi per minute. With the engine running it should drop and slowly increase with throttle position. Also check the FPR vacuum line. If there's fuel in it, the regulator diaphram is torn and the regulator will need to be replaced.
If the pump is bad, look into the Racetronix pump/harness kit. They are very much worth the $$$.
If the pump is bad, look into the Racetronix pump/harness kit. They are very much worth the $$$.
09-28-2009, 03:21 PM
#3
Im trying to get ahold of one. I checked the FPR and its ok, no fuel coming out of the vacuum line.
Would this be the pump:
http://www.racetronix.biz/itemdesc.a...PA-003&eq=&Tp=
And this the harness:
http://www.racetronix.biz/itemdesc.a...WH-003&eq=&Tp=
Would this be the pump:
http://www.racetronix.biz/itemdesc.a...PA-003&eq=&Tp=
And this the harness:
http://www.racetronix.biz/itemdesc.a...WH-003&eq=&Tp=
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09-28-2009, 05:50 PM
#8
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when my fuel pump went out it would stutter real bad and I would have to prime the car a few times to get it to start. It never pop'd or shut off on me those sound like ignition related to me. your fuel pressure seems fine.
09-28-2009, 05:52 PM
#9
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well your pump should put out 41-47 primed key on (not running) 38 is a little low
at idle it is anywhere from 3-10 psi less so really it can be anywhere between 31 and 44. at wot it should be 41-47, which is odd because to simulate wot you take the vac line off the regulator and you have enough fuel pressure... your pump did overheat since it shut off... i would venture to say it is on its way out, ive had nothing but problems with gm fuel pumps. unless your fuel filter is clogged or there is a very small leak somewhere its probably on its way out. the racetronix kit is a good one and i have heard nothing but good things about it on here and other sites and from people i know, it gives the pump more voltage and its a walbro and its rated at 255 lph. runs better and stronger.
obviously your reg is good cos its not leaking any fuel past.
if you are gonna cut an access panel it would be a perfect excuse, even if it doesnt fix it haha you can do 30 min fuel pump changes and youll have the bitchin racetronix kit for when you DO fix it.
stutter and pop could be either...did it throw any codes like random misfires and stuff? when you run out of fuel itll do that, but if you have a bad icm or something it would be able to do that too.
lol im an idiot 95ta told you all that
i say go for it no reason not to upgrade your fuel pump haha
since your psi dropped when you gave it throttle theres something wrong somewheres. maybe taking the vac line off the reg is a bad test because the engine isnt under a good amount of load and it merely simulates? hence why you tape a gauge to the windshield and pray that you can go out on the street to floor it haha
at idle it is anywhere from 3-10 psi less so really it can be anywhere between 31 and 44. at wot it should be 41-47, which is odd because to simulate wot you take the vac line off the regulator and you have enough fuel pressure... your pump did overheat since it shut off... i would venture to say it is on its way out, ive had nothing but problems with gm fuel pumps. unless your fuel filter is clogged or there is a very small leak somewhere its probably on its way out. the racetronix kit is a good one and i have heard nothing but good things about it on here and other sites and from people i know, it gives the pump more voltage and its a walbro and its rated at 255 lph. runs better and stronger.
obviously your reg is good cos its not leaking any fuel past.
if you are gonna cut an access panel it would be a perfect excuse, even if it doesnt fix it haha you can do 30 min fuel pump changes and youll have the bitchin racetronix kit for when you DO fix it.
stutter and pop could be either...did it throw any codes like random misfires and stuff? when you run out of fuel itll do that, but if you have a bad icm or something it would be able to do that too.
lol im an idiot 95ta told you all that
i say go for it no reason not to upgrade your fuel pump haha
since your psi dropped when you gave it throttle theres something wrong somewheres. maybe taking the vac line off the reg is a bad test because the engine isnt under a good amount of load and it merely simulates? hence why you tape a gauge to the windshield and pray that you can go out on the street to floor it haha
Last edited by trippinholyman; 09-28-2009 at 06:05 PM.
09-28-2009, 06:26 PM
#15
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That is exactly the symptoms mine was having when my walbro 255lph bit the dust. Cruise was set at 70 on the hwy everytime it had to go up a hill it would stumble and jerk. It did that for about 30 miles. Then the next city at a stop light it left me stranded in the middle of an intersection. I waited an hour and let the fuel pump cool off and off i went. Parked it and ordered a new walbro 255. By the way what does the pump sound like when you just turn the key on?
Try this... Turn key on letting it fully prime, shut it off wait 30 seconds then repeat this a handful of times. If the sound of the pump changes its your pump...
Try this... Turn key on letting it fully prime, shut it off wait 30 seconds then repeat this a handful of times. If the sound of the pump changes its your pump...
09-28-2009, 07:04 PM
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Hmmm... mine made a rough grinding noise when it hit the can. i doubt it is the fuel filter, but it is worth a try. Maybe you aren't getting the pump hot enough. When it "shuts off" how/when does it happen (after driving around for awhile or just at idle?