Fuel pump question

[Cammy98]

I have a quick question I want to make sure with you guys first though.

My 1998 Camaro hasn't been starting up lately and this point im pretty sure its a bad fuel pump. So my question is, even if I can hear the fuel pump prime when I turn on the car (not turn over) can it still be broken?

I dont wanna do any unnecessary surgery on her. Thanx for the help

[cam98aro]

Re: Fuel pump question

sounds like a bad fuel filter or a clogged sock for the fuel pump pickup

usually fuel pumps work, or they dont

[tkoforpresident]

Re: Fuel pump question

did you check fuel pressure?

[StrtRacer98]

Re: Fuel pump question

usually fuel pumps work, or they dont

Most common, but not always...

A fuel pump can still work, but not supply enough fuel pressure to the rail.

Check your fuel pressure.

[Cammy98]

Re: Fuel pump question

I changed the fuel filter already, still no start.

Im thinking its the pressure related. I dont have a fuel pressure gauge on me.

But I had a friend turn the key and try to turn the car over and I poked the valve and some gas came out but didn't shoot out.

[tkoforpresident]

Re: Fuel pump question

just hook up a gauge to the scraeder valve and check what the pressure is at key on/idle etc.

[Cammy98]

Re: Fuel pump question

Ok got a gauge today hooked it up

Turned the key to on position and I get about 52 psi and when the pump stops priming it goes down to about 46 or 45 psi.

[cam98aro]

Re: Fuel pump question

Ok got a gauge today hooked it up

Turned the key to on position and I get about 52 psi and when the pump stops priming it goes down to about 46 or 45 psi.

thats 100% normal, and your pressure is perfect

not a fuel problem

edit* what year is your car btw?

[Rob Bell]

Re: Fuel pump question

Check for spark and then start checking to see if the injectors are working. To check the injectors you need to get a test light (or maybe a voltmeter would work). You need to see if there is a pulse getting to the injectors

[firebirddrvr]

Re: Fuel pump question

how hard is it to check that? can a local auto parts store do that?

[Rob Bell]

Re: Fuel pump question

No, a parts store won't do it. For the spark, you can either stick a screwdriver into the plug boot and hold it near the engine, it should spark. Just don't shock yourself. Or, get a spark tester for $6 or so and use that. For the injector pulse, you need to unplug an injector and attach a test light or voltmeter to the wiring harness. Then when someone cranks the engine, the light should flash or the voltmeter will show voltage in pulses. I would test a few injectors that way to ensure a sample of them either works or doesn't. You'll probably find that either there is no spark or no injector pulse. Then go from there. If either of these tests passes, then your PCM is probably OK.

Also, before you do this, check the fuse for the PCM just to ensure it's not a simple fix.

[cam98aro]

Re: Fuel pump question

No, a parts store won't do it. For the spark, you can either stick a screwdriver into the plug boot and hold it near the engine, it should spark. Just don't shock yourself. Or, get a spark tester for $6 or so and use that. For the injector pulse, you need to unplug an injector and attach a test light or voltmeter to the wiring harness. Then when someone cranks the engine, the light should flash or the voltmeter will show voltage in pulses. I would test a few injectors that way to ensure a sample of them either works or doesn't. You'll probably find that either there is no spark or no injector pulse. Then go from there. If either of these tests passes, then your PCM is probably OK.

Also, before you do this, check the fuse for the PCM just to ensure it's not a simple fix.

its easier to just stick a spark plug in it and see if it is sparking

[Rob Bell]

Re: Fuel pump question

Yeah whatever works. You just need to know if there is a spark or not. We always used to do the screwdriver method.

[Cammy98]

Re: Fuel pump question

Alright I was actually going to check the spark plugs today hah.

And then I'll move on to the injectors (im thinking that may be the problem)

I checked all the fuses and everything is working fine on that end.

So if the fuel pressure is all gravy does that mean I should rule out the fuel pressure regulator?

Oh and I have a 1998 Camaro

[Rob Bell]

Re: Fuel pump question

I would say yes, rule it out. From your test earlier, the pressure was good and it held pressure after the pump stopped priming. Even if the regulator was "not good" vs totally dead, the car should still start. It may just run like crap. According to other posts, you can verify if the regulator is good by pulling the vacuum line. If gas comes out, it's bad. But since you have a no-start condition, it's got to be either missing fuel or missing spark.