86 Astrovan: Intermittent Hesitation


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Old 09-01-07, 07:40 PM
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86 Astrovan: Intermittent Hesitation

I have a six cylinder, fuel injected, '86 Astrovan that often tries to die and occasionally dies when accelerating from a stop such as a traffic light. Hard to describe but if I try to give it gas when it starts acting up it stumbles even worse so I have to back off and hope it recovers then I can give it gas. Sometimes I can drive a half hour or more without a problem. Sometimes it happens when the engine is cold and sometime when it is hot. There is no pattern.

The problem has been occurring for several months. I have taken it to my mechanic twice. Second time after two days he just gave up. Didn't even charge me. He said he had checked for vacuum leaks, fuel problems, timing, spaqk plugs, ran computer checks, everything he could think of.

I have replaced the injectors myself. At one point I thought it might be the MAP so I replaced that. The mechanic temporarily swapped out the oxygen sensor but that didn't help. Replaced the fuel filter and air filter a couple of times.

The mechanic said he didn't think it was in the computer and I hate to spend that kind of money if it isn't. I have considered maybe the fuel pump because it occasionally does it if the van idles too long at a light. On the other hand when pulling away it acts like it is getting to much gas and drowning the engine. I have no problem when actually driving, just at idle. When it dies at a light though it doesn't stumble. It just stops. Totally different from the way it acts when I give it gas to accelerate from a light. If it had a carburetor when accelerating I'd almost say it was flooding but of course it is injectors.

What ever it is has gotten progressively worse over the months. Use to go days without a problem but now it is every day. While the van is old the engine was replaced with a rebuilt engine about 4 years ago.

Any help or suggestions appreciated.
 
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Old 09-02-07, 03:41 PM
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There is a pressure regulator. If I were you I would idle the car a long time, just to see what the plug color looks like afterwards. Pull some plugs then. Make sure engine does not overheat from idling. Post back results please.
 
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Old 09-02-07, 05:00 PM
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Yes, I was thinking maybe the pressure regulator. I did rebuild it years a go. Can't remember my problem back them but I know it didn't fix the problem then which made me hesitant to try that. Thanks for the suggestion.
 
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Old 09-02-07, 06:28 PM
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I had a similar problem on my 86 Astro, it ended up being the fuel pump. Have a good one. Geo
 
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Old 09-02-07, 08:03 PM
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Almost did the fuel pump today but since it has been checked by a mechanic I've used for years and trust was hesitant to just start replacing parts. Did in the past have to replace the fuel tank because a loose baffle kept knocking the leads off the fuel pump.

Thanks to both posters for seconding what I was thinking. Good to have a sounding board for my thoughts. Will go at it with a bit more confidence I'm not wasting time and money. Also considering the fuel pump relay. Guess I need to go through all three.
 
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Old 09-03-07, 08:18 AM
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I would suggest going to your mechanic and have the fuel pressure checked before replacing the pump, it's in the tank and a pain. Have a good one. Geo
 
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Old 09-03-07, 08:40 AM
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Actually the fuel pump is no longer a pain to get to. Long ago I did what Chevy should have done and put an access panel in the floor of the van. <G> May change it just to eliminate the possibility.
 
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Old 09-03-07, 12:03 PM
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So then you don't have to lower tank, drain out gas, etc., to change it?
 
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Old 09-03-07, 07:35 PM
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Correct. Just remove the floor panel to access the tank and remove the fuel filter. No need to drain the tank or drop it. In fact of the things I will try it will be the easiest.
 
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Old 09-04-07, 06:02 PM
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Talking RE: Fuel Injected, '86 Astrovan

Hello :

Your Astrovan have Mass Air flow sensor ??

Try cleaning the Mass Air flow sensor with tuner cleaner ..

Check this article

http://forum.doityourself.com/showthread.php?p=1225162#post1225162
 
 

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