Chevy & GMC Vans

Hi... I just started using my astro after a year and a half stored. I had kept starting it and moved it back and forth in the garage where it was stored. I'm having some problems when passing other vehicles on the highway and when I stop it sometimes stumbles and dies... I had some codes on the scanner, Egr and an O2 sensor, cleaned the egr and changed the sensor... worked fine for an hour or so. Then started doing the problem again, but this time no codes...I have a fuel/air ratio gauge and when the engine dies or hesitates it goes all the way to "lean". I also find the fuel pump a bit noisy and the sound changes a bit when the engine is about to die... Haven't changed the filter nor the pump yet, just wanted to see if you guys had any ideas... Thanks...

Have you put fresh gas in it? I would change the fuel filter first. Then throw a pressure tester on the fuel rail and see what it does when it dies.

Well i did use the van for a couple of days... I have put gas 2 times already... The problem persists. I am planning on changing the filter and posibly drain most of the gas so when i put the new theres less chance of the gas being bad. Thanks, Lifted...

When I bought my '99 Astro 4 1/2 years ago, I noticed the fuel pump made a loud buzzing noise, but it ran OK so I decided to just drive it, and see if it had issues other than the noise. The van still runs fine, the fuel pump is still noisy. Just thought I would mention it, apparently some noisy fuel pumps still work fine.

VanGoGo wrote:When I bought my '99 Astro 4 1/2 years ago, I noticed the fuel pump made a loud buzzing noise, but it ran OK so I decided to just drive it, and see if it had issues other than the noise. The van still runs fine, the fuel pump is still noisy. Just thought I would mention it, apparently some noisy fuel pumps still work fine.

It seems with these fuel pumps the concern is a change in tone. Some are way louder than others, but even the loud ones run for miles and miles and miles.

Well, changed the fuel filter today... it was very dirty but the problem continues. When the van is idling it just suddenly dies. Fuel pump keeps working. A couple of times it started but idle was around 2500 rpm, and i hit the gas pedal and it didn't go lower, I've also noticed idle is a bit low, around 700rpm. No codes, I'm guessing it's an electrical fault... No clue...

Might check for a vacuum leak, sounds like one.

I'll do... thanks...

Well, I checked and removed the IAC valve, cleaned it, worked great for a couple of tries... Took the van out for a test, started stalling again. now it's worse, as soon as i come to a stop it just quits... Still no codes... This is annoying...

This van was in perfect working condition when I stored it... I've had it since 2001, wouldn't like to let it go... Man this is getting on my nerve.

As someone else said, a noisy pump does not mean it is bad or about to go bad. Had one that whined for about three years. The clue is the change in the sound of the pump. Generally, a good pump runs around 60 PSI. If I recall, the minimum starting pressure is 54 PSI and the minimum to keep the engine running is 40 PSI. If the pump is changing sound, it is changing RPM and that means thew pressure is changing, most likely.

If you have never replaced fuel pumps before in these vans, pretty much everyone will tell you, if you buy an aftermarket pump, it will fail within a year. They are much cheaper, but they do not last. You would be better off to get a salvage OEM pump than an after market pump.

When the pump gets noisy - or better yet, per recommended maintenance, change the fuel filter!
Quieted mine immediately.
Madmatt

Changed the IAC valve today... same thing, started fine up to 1800 rpm, then idled at 900-1000 rpm, ran for a couple of minutes. Turned the engine off and started it again, it idled low... around 700 rpm. Went to auto zone, bought a fuel pressure tester, throttle body cleaner and did some cleaning on the TB and then put the pressure tester on. Turned the switch on, 60 psi for a couple of seconds, then drops to 55 psi... engine running goes up to 60 when starting then down to 52 while running... noticed that when i accelerated the engine the pressure fluctuates a bit, goes 4 or 5 psi up then back to 52. I ran the engine for about 15 minutes and then it died, the pressure dropped to 40 something and the engine died. Pressure stayed at 40 something until i started the engine again(no leaks), then the same thing all over again, it just took a couple of minutes to do it again... I guess it's the pump, the sound was changing all the time...

Yup...time for a new pump!

Thanks...