last time...is it the fuel pump?

[stone_mound_camaro]

ok...im about to maqke the fianl decision to get my fuel pump replaced, bu t i want to be completely sure its the pump...sypmtoms are jerky acceleration hesitation...generally running sluggish... when i first bought the car january of 06 it was mildly apparent. only happeneing interemittently while driving...now the problem has progressed to jerlking pretty much the whole time while accelerating.

also...when i prime he fuel pump and listen near the engine, it sounds like the pressure isnt constant.you can hear a sort of fizzing sound..now is this my pump?

fel filter just replaced, so thats not bad....also when i brought it in to a mechanic at first when the problem arose, he checked the spark plugs and said they were ok...so it probably isnt that. car is at 140,000. was at 120ish when i bought it and i beleive the pump was never replaced. car is also a 94 v6.

o yea..and i ran seafoam through it so its not te injectors.
so...... fuel pump?

[Mr. Azrael]

Originally Posted by stone_mound_camaro

ok...im about to maqke the fianl decision to get my fuel pump replaced, bu t i want to be completely sure its the pump...sypmtoms are jerky acceleration hesitation...generally running sluggish... when i first bought the car january of 06 it was mildly apparent. only happeneing interemittently while driving...now the problem has progressed to jerlking pretty much the whole time while accelerating.

also...when i prime he fuel pump and listen near the engine, it sounds like the pressure isnt constant.you can hear a sort of fizzing sound..now is this my pump?

fel filter just replaced, so thats not bad....also when i brought it in to a mechanic at first when the problem arose, he checked the spark plugs and said they were ok...so it probably isnt that. car is at 140,000. was at 120ish when i bought it and i beleive the pump was never replaced. car is also a 94 v6.

o yea..and i ran seafoam through it so its not te injectors.
so...... fuel pump?

Check the fuel pressure at the fuel rail to see where it is... While the symptoms could indicate a bad fuel pump it could also just be bad injectors. While I do like Seafoam that will not necessarily insure that you don't have an injector problem... At your mileage I would be interested in more information regarding what was done and when (plugs, wires, injectors, hoses, belts, etc) These symptoms could be just about anything related to the 4 stroke cycle (plugs, wires, ignition, fuel pump, fuel injectors, vacuum, etc)...

[stone_mound_camaro]

well the thing is...i previously owned a 94 v6 and had the same problem at about the same mileage;which was diagnosed as a fuel pump and ever since it started on this car i have thought "fuel pump". And the problem is i dont have the money to wast on a diagnosis and have the mechannic tell me what i already knew the problm was, you know?


what are the things i can check for myself with SIMPLE tools. and not having to buy anythig extra...ie gauges and so on.

[Mr. Azrael]

Originally Posted by stone_mound_camaro

well the thing is...i previously owned a 94 v6 and had the same problem at about the same mileage;which was diagnosed as a fuel pump and ever since it started on this car i have thought "fuel pump". And the problem is i dont have the money to wast on a diagnosis and have the mechannic tell me what i already knew the problm was, you know?


what are the things i can check for myself with SIMPLE tools. and not having to buy anythig extra...ie gauges and so on.

Well just do the simple diagnoses, check for air leaks, listen to the injectors (you should hear then ticking softly), check your plugs and wires. An ignition issue under load can cause the same symptoms and plugs, wires, etc are even less expensive than a fuel pump replacement.

Good luck!

[hotrod_chevyz]

"sypmtoms are jerky acceleration hesitation...generally running sluggish..."

Sounds tune-up related. The descripton of the problem doesnt sound like a typical fuel pump woe.

Ive seen partially plugged catalytic converters act like you have described, just to thow that up. 140K miles is a long road for converters, injectors, 02 sensors, pumps.

[stone_mound_camaro]

i knew putting "running sluggish" was gonna mess up my description...i was at work and writing it fast to decide whether to get the work done when i got off. a more accurate description of the problem is..



things that have been done/repaired...plugs, cat just replaced,injectors checked, fuel filter air filter.

the car idles fine...the problem only occurs while accelerating. When cruising, it runs smoothly with minor jerking every...hmm... i would say 30-60 seconds...the way it jerks is like you 're driving down the road and you run over a patch of glue. stutters for a quick second but resumes driving fine. i've stated the symptoms in at least two other threads in the past, but cant find them to link it.

but what makes me think its the pump are my past threads, and when i prime the pump, i hear the pressure fizzing(in the engine bay), like its inconsistent.

[wrightz28]

Originally Posted by stone_mound_camaro

what are the things i can check for myself with SIMPLE tools. and not having to buy anythig extra...ie gauges and so on.

If you think you're going to nail this, you need a fuel pressure gauge.

[stone_mound_camaro]

ok..im trying to search up a way to check fuel pressure on the internetz. cant seem to find it...is it easy to do? can you provide me a link to how to check it?

[wrightz28]

You screw the guage onto the fuel rails schrader vavle, done.

[stone_mound_camaro]

can you point me in the direction of said fuel rail, sir?

[marc-o-matic]

Top of engine,under upper intake manifold

[wrightz28]

Exactly! follow along the fuel lines to the manifold, and find what you seak.

[stone_mound_camaro]

thanks marc...and you as well wright....have you thought about opening a shop yet? you have all the answers...but anyway, one last question, what pressure range am i looking for...and am i looking for pressure in a certain range, or am i looking for the pressure to be stable/consistent (with keys in ACC position)

[wrightz28]

When running you want to be steady at about 45 PSI to 55 PSI, Anything lower than 40 is a problem for sure.

Now, the trick thing tho is that the pressure mey be an acceptable PSI but the rate of flow may not be, but you usually don't have to get into that.

So you want a running pressure test. As well as a static test (key on engine off, the pump will prime the system. It should hold pressure and slowly bleed off., rpid loss could spell out a regulator problem.

Open a shop? No, I only know what i do becasue I don't have the money to pay a shop, let alone open one

[marc-o-matic]

You'r welcome
I do run a repair shop.
The pressure should be 41-47psi. running