Fuel pressure issue - 95 Astro - please help (2024 Update)

not directly, but here's a thought:

I get a LOT of GM trucks with a 'no 4th gear' complaint

if you drive it just right, it WILL go into 4th............but the problem is plugged fuel filter, thus more throttle pressure, thus ECM keeps it in third

SO:

do what I do to demonstrate to the customer where the problem is...............monitor O2 sensors + injector pulse width

if you see O2 going lean and at the same time the IPW is getting longer and longer, you have a fuel delivery problem.............filter or pump

just a thought

G
Reply to
TranSurgeon
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That's true enough Gary, but it still doesn't change the fact that Glickman is full of shit.... yet again.... The PCM doesn't have a clue what the fuel pressure is. It may think the engine is lean due to the feedback it gets from the O2 sensors and increase the fuel trim to compensate. But it still doesn't know if the problem is fuel pressure, a bad sensor, or something else. It just knows it is having to add fuel to get an O2 response and will set a code if it reaches a certain limit. Bob

Reply to
Bob

exaust/convert

Actually if your removing the tank one of the first things you do is disconnect the filler pipe. Then you siphon. It doesn't get any easier. As for running the engine till the last bit is out, a total waste of time.

Reply to
TaskMule

I tell ya, go back over what you've already done. You may have a bad part in the plenum area. Also, there is a strainer in the tank with the fuel 'assembly'. Is that replaced? That fuel assembly is best changed completely out and not piece-mealed.

Reply to
ed

No problem to siphon the fuel out of a TRUCK. haven't seen one that has anything to block the fill yet. Some AUTOS do have though.

Reply to
Steve W.

exaust/convert

oh, I know

I just thought it might help somebody else.........some one who's not suffering from 'cranio-rectitis'

Reply to
TranSurgeon

Who said anything about removing the tank? Hell, the whole idea that his fuel is contaminated was just someone's brain fart. It's time he quits throwing parts at it and listening to nitwits like glickman and starts doing some diagnosing. Bob

Reply to
Bob

snip

I couldn't agree more

Reply to
TaskMule

Foaming at the mouth again are we bobby socks? Whatever you've got, keep it to yourself. There isn't a vaccine presently on the market that could possibly deal with your disease.

I request to see your "credentials." Went to auto-shop at high school perhaps? Lincoln Technical Institute, or maybe you're just a hack car breaker who came up the hard way, breaking one car at a time along the way.

I imagine your career has peaked, and you're never going anywhere beyond where you are now, which is changing oil and topping up radiators. Must suck to be you, but then, you get what you deserve.

Lg

Changes tune midstream. Nitwits. Monitoring fuel pressure is a non issue. It is easy to do. You all try to make it sound like rocket science to boost your own egos, but there are many amateurs that know the magic secrets you pretend to have hoarded all to yourselves.

Lg

Reply to
Lawrence Glickman

Wrong on all counts numb nuts....

For once Larry you are right........ there ARE amateurs that know a lot about auto repair, you just aren't one of them. You are just here wasting peoples time and resources with your useless suggestions. Bob

Reply to
Bob

It is inescapable to the casual observer, that you NEVER ANSWER ANY QUESTIONS, but rather just spew vitriolic.

I asked you for Credentials, evidently you have none to present.

Nuff said.

Lg

Reply to
Lawrence Glickman

You said you could get fuel pressure readings from the data stream of a 95 Astro, and you have the nerve to ask ME for credentials? You're the one doing all the spewing.... all I did was point that fact out. Why don't you go ahead and explain just how you can get fuel pressure readings from the data stream.......... Bob

Reply to
Bob

It is inescapable to the casual observer, that you NEVER ANSWER ANY QUESTIONS, but rather just spew vitriolic.

I asked you for Credentials, evidently you have none to present.

Nuff said.

Lg

Reply to
Lawrence Glickman

Well gee Larry, the only road to my shop was closed for two months last summer. While there was access to my shop through a park many customers had a hard time finding me, taking a short cut through the park or across neighboring lawns. One week after the road reopened we were hit with the worst flood in this towns history (8ft deep in my shop). In spite of all that last year was my best ever. You want credentials? I could type a long list of them but what would be the point? The only thing that really matters is that my customers are happy and keep coming back. By the way I rarely work on cars any more, I have employees for that. Things are damn good and only getting better. I get paid for repairing cars, pointing out your stupidity I consider a public service. Of coarse if you were to quit flapping your gums when you don't know what you're talking about my service wouldn't be needed any more. Bob

Reply to
Bob

So you feel it is necessary to point out other people's stupidity to them, then you are going to be a VERY BUSY person. In fact, forget about taking time out to sleep or eat !

Lg

Reply to
Lawrence Glickman

I just test drove the van with the fuel gauge hooked up and the needle swept between 50psi and 70psi when I accelerated. The pressure never dropped below 50psi even while the van was running poorly.

I also drained the gas and re-changed the fuel filter and it did not help.

I will try and better explain how it is acting.

The van always starts and runs fine. It drives fine for a short distance then starts to run very bad, sometimes backfires, stalls, and completely dies.

It takes as much as 10 to 15 minutes of regular city driving to cause these symptoms or 2-3 minutes of driving under a load (when I hot rod it).

If the van completely dies, I can turn it off for 10 seconds then right back on and I can usually baby it home (1-2 miles). If I leave it off for 15 minutes it usually runs quite a bit better.

I have replaced: Leaky CPI (spider) Inlet outlet fuel lines (nut kit) Fuel Filter Fuel Pump and strainer Exhaust from O2 sensor back (waste of $$$... my dumb fault) Drained the gas

Is it time to take it to a mechanic? I am out of ideas and do not know what else to check. Is there a certain test that a shop could perform that would tell me what is wrong such as a general diagnostic or run it on a computer?

Does this still sound like a fuel delivery problem?

Reply to
daveg.01

Well you eliminated fuel problems. You say it only happens when the engine gets warm? Go to a local electronics place and get a can of "component cooler" (basically R-134A) Run the vehicle till it starts to act up. Then pop the hood and spray ONE sensor/part at a time. I would start with the ignition coil, then the base of the distributor. Then work your way around the engine compartment. After you spray a part run it some, when you find the bad part it should become obvious since the problem should go away. I would almost guess the coil is breaking down when it gets hot, but there are a LOT of sensors that can be affected by heat.

Reply to
Steve W.

take off the goddam EGR valve and make a plate to cover the opening, and re-test it

or take off the EGR, make sure it's fully closed, put it back on but DON'T hook it up, and go for a drive

if your brake pedal gets 'hard to push' when this happens, it's the EGR hanging open

Reply to
TranSurgeon

No it doesn't. Usually if you have a fuel problem the engine runs better, if anything, as the engine warms up. Initial pressure, key on, should be

60 - 65 psi
Reply to
Rich

I am going out on a limb here and make a guess, actually a couple. One this thing has a distributor. And as such it has a pick up coil, a magnet, and a module. I would want a good scope put on the rig and watch the wave patterns on the pick-up coil. while some of it sounds fuel related, the back fire doesn't. I have ran into the same general symptoms you describe in the past, except the time to restart was usually longer, but then by the time I got them they were pretty much undrivable they had gotten so bad.. At 105,000 miles the bushings in the distributor are probably worn as well. But I wouldn't change unless you can get a scope to verify which means getting it to act up while its hooked up. Whitelightning

Reply to
Whitelightning

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