1995 Chevy Astro sputtering when giving it the gas

Tiny
CABMAN86
  • MEMBER
  • 1995 CHEVROLET ASTRO
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 131,000 MILES
My astrovan is giving me fits. When driving at a normal speed it purrs like a kitten. When I give it gas to speed up it starts sputtering like its missing on a cylinder. This has been going on for a week now and I have done everything I know to do.

the diagnostic codes show it needed a IAT sensor. I replaced it today and to no avail. It still does the same thing.

When it is cold (first start up of the day) it runs great til it gets warm(about 2 miles). Then it starts. As I drive farther it also sputters on start and start.

i have checked the plugs, wires, cap and rotor and all are fine. It is getting great fire. I replaced the fuel filter thinking it may not be getting enough fuel. Didnt help. I replaced the IAT sensor and no help there either.

any help will be appreciated.

thanks
Roger
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Thursday, March 11th, 2010 AT 11:10 PM

13 Replies

Tiny
JACOBANDNICKOLAS
  • EXPERT
Have you actually checked the fuel pressure?
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Friday, March 12th, 2010 AT 10:07 AM
Tiny
CABMAN86
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I just had a fuel pump put on in october. Didnt think about the pressure.

It only does this after it gets warmed up and when giving it the gas. It doesnt sputter at all going straight and level
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Friday, March 12th, 2010 AT 3:54 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
I understand why you haven't checked pressure. However, it sounds when more of a demand is placed on the fuel pump, it may not produce. It could even be related to the fuel pressure regulator. A vacuum leak could be the problem or a partially plugged catylatic converter or EGR valve.

Here are the directions as to how to check fuel pressure and the regulator. Just for the heck of it, check it. It is easy to do. Also, you will need a fuel pressure gauge. Most parts stores will lend or rent them.

http://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

The directions include a video showing you how to do it.

I also recommend checking the EGR and for vacuum leaks.

Let me know what you find, Roger.

Joe
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Friday, March 12th, 2010 AT 7:33 PM
Tiny
CABMAN86
  • MEMBER
I had a new egr valve installed last week. That was when the problem I have now started. I was looking through the forums and saw that most have suggested a vacuum leak for my problem. When the weather clears here I will go out and check it. I watched the video and read the injector check. I have the spider injectors so thats another problem. Cant get to them. I never knew about the pressure regulator. Gotta check that too.

Dang rain here wont let ya do anything down here

thanks for the help
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Friday, March 12th, 2010 AT 7:53 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
If the problem started when you had the EGR replaced, then check for vacuum leaks there and make sure the valve is working properly. That is most likely where the vacuum leak is coming from.

Also, I don't know where you are, but you must be west of Pittsburgh. The rain here is to start tonight for the next several days plus we just had about 2 feet of snow melt. What a mess.

Let me know what you find. Something tells me the EGR is bad or leaking.

Joe
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Friday, March 12th, 2010 AT 8:14 PM
Tiny
CABMAN86
  • MEMBER
I am in NW Louisiana. Its been raining here off and on since monday night.

It was really sluggish before I replaced it and getting hard to start. It started the sputtering after it was replaced though. I will check there first thing in the morning. It hasnt rained since about 7 tonight so it might just be dry enough. Theres no rain til tuesday so the powers that be say.

I have had so many tell me so many different things but I never had someone tell me the new EGR could be bad. It was bought at auto zone so anything is possible.

Thanks again and I will let you know what happens tomorrow
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Friday, March 12th, 2010 AT 9:11 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi:
I was wondering if you had any luck. To me, if the problem got worse when the work was done (EGR), it seems like the problem has to be in that area.

I hope you find it and it's an easy fix.

Let me know.
Joe
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Saturday, March 13th, 2010 AT 11:58 AM
Tiny
CABMAN86
  • MEMBER
No luck so far today. It was a bright and sunny one too. I sprayed around the egr and no change in the idling. I did find a bad hose at the carbon canister and replaced those. Still no luck. I popped the distributer cap and it still looked new. I couldnt get to the vac hose under the intake tho. May be it. I dont know if I should even try to take the intake off to check. Way past my experience.

The computer still says the O2 sensor is bad. It has 2 of them but I cant find the upper one. Its supposed to be on the right exhaust manifold but I couldnt see it on either. Guess I will have to gat under it tomorrow to see if I can see it there.

When I had the carbon canister hose off it seemed to take alot longer to start sputtering. It wasnt as bad either. When I replaced the hoses it got kinda bad again.

Could it be the carbon canister is stopped up? I never heard of that going bad
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Saturday, March 13th, 2010 AT 7:41 PM
Tiny
JACOBANDNICKOLAS
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Let me know what you find. Also, is there any fuel coming from the canister? I've seen them get fuel in them from overfilling the fuel tank.
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Saturday, March 13th, 2010 AT 10:11 PM
Tiny
CABMAN86
  • MEMBER
Nope. Dry as a bone. I replaced t he hoses on it and did some checks. Couldnt find anymore leaks. Someone said the accelerator sensor could do that to it. I have no idea what that is or where. I miss my old 75 dodge pickup. It had 2 vacuum lines and pretty much nothing else. So easy to work on.

One thing. Does the egr valve have a vacuum line coming from it? Someone said to check that and I cant for the life of me see one or a place to put one. Its a tight fit so I just may not be seeing it.
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Saturday, March 13th, 2010 AT 11:42 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
I believe the EGR on yours should be electric. Also, (I can't remember) did I ask you to check the intake. They did have a problem with intake leaks.
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Sunday, March 14th, 2010 AT 4:28 PM
Tiny
CABMAN86
  • MEMBER
It is electric. I do hope its not the intake. Like I said, that is way past my experience. I couldnt get out there today. I got out of bed and broke my foot just by stepping off the bed. Wierd huh? Guess I am getting old. Hehe. Its a slight fracture though. Will be ok in about a month.

I am gonna get out there tomorrow though. Gonna take a stool out there with me.

Thanks
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+1
Sunday, March 14th, 2010 AT 9:34 PM
Tiny
JACOBANDNICKOLAS
  • EXPERT
First, take care of that foot. I don't know how old you are but moving the wrong way can hurt anyone. As far as the intake, if it is bad, I think you could do it. Basically it is just removing and replacing it with a new gasket. Of course, you need to drain the coolant first, but not rocket science.

You let me know what you find and I hope you feel better. The car can wait. Take care of yourself.

Joe
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Sunday, March 14th, 2010 AT 11:18 PM

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