You'll need to check the fuel pressure, both turn-key, engine idling, and at part-throttle conditions.

Turn-key should be around 43.5psi.
Idling should drop 3 to 10psi from turn-key.
Part-throttle pressure should slowly increase with throttle pressure.

Also listen for the static whine of the pump when you turn the key to ON. It should stay loud, and not taper.

 

You know ive been trying to listen for my whine at start up lately and haven't heard a thing... hrm... my starts have been getting a bit longer lately too...

Would - engine reporting lean, stumble during partial accelleration in gear around 2000 rpm, fade of high end power around 4-5k rpm... etc all be symptoms of a pump not working like it should?

 

All those symptoms might be indicative of a failing pump, yes.

Then again...they could be from a bad opti too.

 

Tiz why i'm starting to hate my car... although its got a nice computer with all these sensors to tell me whats wrong, if the sensors aren't working right it messes up the whole analysis process! on top of all that we have this beatiful piece of machinery called the optispark which can misbehave 10 different ways when its going bad (from slowly fading out to just plain crapping out) to randomize everything.
I guess my best bet is to do a fuel pressure test as suggested.. thanks guys! Is this an easy enough thing that you can do at home? is a fuel PSI guage cheap and easy to use for the moderatly-retarded home mechanic?

Thnx for the info RamAir

 

When my pump was going south, scans showed that the car was leaning out badly in PE mode. Looking at the injector pulse widths and duty cycles showed that the computer was calling for as much fuel as could be delivered. Suspecting that the pump was weak, I did a pressure test to see if pressure dropped at WOT. I ran a guage to the windshield and taped it in place. It dropped to the low 30's to high 20's at high RPMs. A new Racetronix kit fixed that problem.

 

nateh - your my hero! Thats EXACTLY what my car's doing, i'm gona buy me a pressure guage and do what you did asap. Do you remember what cells were richening? mine were 14 and 15...

 

Cell 15 was where mine was when it was leaning out. I don't remember seeing it go to cell 14, but it could have I suppose. I do remember being alarmed at how quickly and badly it was going lean any time I got above 4000 or so in PE mode. I was worried about damage. Good luck!

 

I had this happen to me about 2 years ago. When I would try to crank the car, it would take 3-4x longer than usual. And it was getting worse. It started embarressing me. I thought it was an ignition problem.

I went to the dealership, b/c I had the warranty, and they did a simple test. They told me to turn the key to the ON position, then off. And repeat that about 3x. Then, on the 4th try to turn it all the way over and crank it. If it cranked right up, it was the fuel pump, and if it still made the stalling noise, it was related to something else.

It did, after the 4th try, it started right up, and they brought the fuel pressure gauge out there and tested it. Sure enough, it was the fuel pump. Try that, and see what happens.

But the longer starts are a good sign.

Good luck!

 

I had this happen to my winter car over the winter. The car started really hard for no reason. The next day I took it into the shop and my mechanic told me it was my fuel pump.

I had the same problems you had.

Anyways, it costed me $400 dollars. This was done on a 93 oldsmobile Bravada

 

I just bought one last week, $35 at Pep Boys, pretty nice gauge too. Pretty simple to use, just hook it up to the schraeder valve on the fuel rail. I have had a stumblimg problem that I was certain was fuel related lately. I'm pretty sure it was from the fuel pressure regulator, the pressure didn't move from turning the key on to starting the car. Installing a new one this week to see if that does it.

 

Is the fuel pressure regulator easier to get at then the fuel pump? About how much does one of those fellas cost?

 

Oh, I'd say it's about 100x easier to reach the regulator than the pump A good new aftermarket pump is only around $125 which I found is about the same price as a good aftermarket regulator, which seems strange to me.

It's the piece that the fuel supply line runs into (the fuel line farthest back, closest to the firewall). It's attached to the fuel rail in the back under the cowl. I removed the fuel rail to get to it, which is pretty simple. Just disconnect the two fuel lines and remove the four bolts holding the fuel rail down and remove. I think it could be removed without taking off the rail but the rail wasn't that hard to get out and it makes accessing the regulator much easier so I did it that way.

The fuel pump is inside the fuel tank. If you remove it the "correct" way it is fairly difficult. It involves removing the entire rear differential (which is a whole project in itself) , part of the exhaust and other items and dropping the tank. The "easy" way to do it is to cut an access panel in the flat storage area behind the back seat. If you need to change the fuel pump and your doing it yourself that's a good way to go imo. There are several good guides on it here if you search.

 

Go to Autozone and borrow a FP guage for free. Most people don't know that Autozone will lend out just about any uncommon tool you need. All they ask is for a deposit that you get back when you return the tool.

 

We dont have them autozone places up here in Canada BC eh I'll try lordco or mopac or something..