97DerekTiburon

Should you be able to hear your fuel pump from inside a quiet car in a quiet neighborhood? It should start working as soon as the key is in the run position yet not in the "start" position correct?

I can hear it (humming) when I jump it from under the hood but not when I turn the key on.

Any ideas why this is?

(This problem seemed to be different enough from my previous post to start a new thread, sorry if I'm wrong about that.)

Dark Shark

You sure its your fuel pump? Try putting your hand on the IAC valve. This thing:


It vibrates/hums when you turn the key to "Accessories on". You're probably just hearing that, in which case that's normal. Could be wrong, but your description was a little hard to follow.

97DerekTiburon

Ya know, I need to go check out that IAC... I need someone out there with me to turn the key. I don't hear ANYTHING when I turn the key. I hear a hum when I jump the FP with a wire though. I can't hear (or didn't pay close enough attention to tell) where the sound is coming from though.

If I jump the FP and hear a hum, could that be the IAC if the FP is not functioning? Could I be hearing the IAC when I jump the FP?

OK, so I jumped the FP from under the hood, pulled out the back seat and stuck my head under there with almost total silence around me. I couldn't hear the FP under the seat at all, NOTHING. I jumped back out and heard that faint humming from I guess the IAC or close to it.

So do I now suspect the FP?

(this is now getting very close to my previous thread, sorry.)

Dark Shark

Ah, I hadn't read your other thread, so i didn't understand your situation. I've never tested the fuel pump, so I'll let someone else help you with that, just keep in mind that that IAC does make a humming noise with the key on, so that you don't mistake that for something else.

Blank_00Tib

I haven't read your other thread but I know your IAC makes more of a buzz then a hum and you'll hear your FP hum if you go put your ear near the gas cap.

Ericy321

TO test the fuel pump disconnect the return line or something. You should see fuel coming out.

Bullfrog

If you need to troubleshoot a noise in the engine and have an idea where its coming from but cant pinpoint it you can make a poor man mechanics stethoscope. Just use the long tube from a vacuum and place the tube on the the part you think is making the noise (in your case the IAC). This will help filter out other sounds around the area you are testing.
(good for testing if your valves are tapping or if your just hearing your injectors)

REDZMAN

If you jump your fuel pump the way I did the DIY for it, you'll hear it whirr. It's BEHIND you under the rear seat bottoms.

If you are in the car, turn the car over, and don't hear it, you are NOT getting a signal to it that your engine is turning.

My issue was my Crank Position Sensor, the bolt was loose and the sensor had backed out enough that it wasn't sending a signal to fire the pump. I cleaned it, replaced the O Ring, and tightened it, she started right up.

Bullfrog

This thread has a great picture of where the sensor is located.
http://www.rdtiburon.com/index.php?showtopic=26390&hl=

Also according to that thread, its a somewhat common issue by the lack of this sensor at junkyards.

97DerekTiburon

OK, jumping the fuel pump yields no sound from the backseat location. I took out the CPS and cleaned it. No change, just engine turning over.

I may be wrong but it looks like it's either CPS or Fuel Pump at this point. I have no problem replacing either but I'd rather replace the actual culprit!

If I was a gambling man, which one would I put my money on? Or is there a way to eliminate one using some logic I don't seem to posess at the moment?

BTW I still have no CEL therefore no P0335. Does this point the finger at the fuel pump even more?