Javier97Z28

In regards to my hard start problem:

http://web.camaross.com/forums/showthread.php?t=325195

I've now confirmed the car's problem is not the opti or ignition related.

Went outside with my borrowed fuel pressure gauge (Thanks Zmandan) and hooked it up. Had my wife put the car into the on position, guage read 41psi (close, ideal is 43.5).. dropped to just under 40psi within a minute (not supposed to happen so quickly as I understand). Had my wife crank the car up and it started right up, but only dropped 1psi, it's supposed to drop 3-10 psi at idle from what I've read. Turned off the car, released the pressure in the gauge.

Repeated the process, turned the car to on, this time, only got 20psi on the gauge. Hmmm I wonder... try to crank the car, started up, sure enough died immediately after the fuel pressure dropped to ZERO.

Released pressure in the gauge again, placed key in ON, 0 psi. No fuel pressure whatsoever. Car makes no effot to start (cranks).

So there you have it. I imagine it's the fuel pump, I can't imagine a filter would cause this much hassle (it's not even that old). I don't think the regulator would be at fault here either would it?

Gonna wait on some replies and hopefully I can order whatever I need this week from Thunder. If it's the fuel pump I'll be ordering a racetronix 255lph kit with upgraded harness.

Usually it starts after a while, but this time it's 100% deadl. Been about 15-20 minutes since the pressure died, and it hasn't come back up from 0 psi since and the car will not start. Thought it would take a while to diagnose, guess I got lucky.

Mtrhds94Z

You might want to check the fuel pump relay before you change the pump...

Javier97Z28

Would the relay cause problems even when the car is cold?

I just went outside and I guess it's probably well over an hour since I first posted. and the car started right up w/ the right pressure.

So it's still intermittent.

slopokrodrigez

To eliminate the relay, put 12 volts straight to the fuel pump prime connector. This will go straight to the pump bypassing the relay. I think your pump starts to crap out as soon as it warms up. Let the engine run for a little while and monitor the pressure. Try starting a few times while putting voltage to the prime connector.

BTW have you run real REAL low on fuel lately?

Dave

Javier97Z28

Yes.. and at the track at WOT no less a few months ago.. heh. Thought I had more gas than the gauge led me to believe. It sputtered and almost cut off, but I managed to bring it around before I ran out completely.

This is why I thought the problem was the fuel pump.

Spinner

Racetronix

Mtrhds94Z

IT probably is the fuel pump.. I just tossed the relay idea out there as it's a cheap easy fix, and your saying 0 pressure, intermittantly, it could be that..

Javier97Z28

This is true.. and since I can duplicate the problem pretty easily now (it seems as though you leave it sit for a long time and it will start.. let it idle for a minute and shut it off, then the pressure does the drop to 20, start, drop to 0 die, then won't start again) I can give it a shot.

Anyone have a part # for it? Or is it a common relay I can buy at an autoparts store?

slopokrodrigez

As Bill Invall would say, "Here's your sign"

It's not the relay, why don't you test it like I told you???????

Javier97Z28

b/c I'm smack in the middle of remodeling my kitchen, mounting cabinets and such

Every once in a while I'll run back and forth and fiddle with the car for a few minutes.

Is the test your telling me to do something that's real quick (ie, easy to access don't have to lift the car).. just wondering, if it is, I can test it out right now.. if it's not, i'll try it this week sometime. As far as testing it goes, where is the fuel pump prime connector? So I should basically just jump that with 12+ and then do all my tests again correct?

Z28whiteboy

Just out of curiousity, how many miles do you have on it? I recently hit 130k and my fuel pump has been the cause of many problems on my car. Starting being one. I just had to replace it and immediately it fixed my starting problem and i even feel a little more power. I'd say to be sure to check the fuel filter as well, i just found out you're supposed to check that out every 15,000 miles. Let us know what happens.

Javier97Z28

will do, i'm at approx 86k miles right now.

Will be changing the fuel filter as well for sure.

Javier97Z28

ttt for the day crew.

I haven't really tested anything else, but I'm just about ready to order the fuel pump. Any other input?

Javier97Z28

Guess I should just get it ordered huh?

Javier97Z28

Yeesh. not a single reply today :/

Oh well, I'm bringing a voltmeter home w/ me from work today to test the relay real quick, just want to eliminate that.