Mechanics

FUEL BURING OUT THE TAIL PIPE, 10MPG.

1990 Ford Aerostar

Engine Performance problem
1991 Ford Aerostar 6 cyl Two Wheel Drive Automatic

I just bought a used Aerostar van, and it is going through gas way too quickly. Me and my dad replaced the ancient spark plugs and cap/rotor, sprayed the thing out with carb cleaner, and gave it a burly gas treatment. Still getting 10 mpg, and I can see that its all flying out the tail pipe. Figure I will have to just start replacing things, but were should I start? What is most likely the big problem?
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Iroshiyan
August 6, 2009.




Does the engine have normal power? Has the check engine light come on? Have you checked to make sure the catylatic converter isn't plugged? Is the air filter clean?

It has fantastic power, it feels like it WANTS to go. In fact, it is accelerating on its own sometimes and I thought that was odd. Air filter is pristine, check engine light isn't on, and I'm not sure how to check if the cat. Converter is clogged up, I figured that the gas cleaner treatment would help that. I don't live in an area with smog checks, could I bypass the cat. Converter?

Tiny
Iroshiyan
Aug 6, 2009.
If you have a lot of power, the coverter is most likely fins. It sounds like you have gone over it really well. How many miles are on it?

It is reading 893,200 and I'm assuming that it has already went around once, considering that its a 1990. So that would make it almost 200k I think. All I know is that the tail pipe is covered in soot, it reeks of carbon, and you can see the fumes/smoke coming out of the pipe.
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Tiny
Iroshiyan
Aug 6, 2009.
It could have something to do with the temp sensor. It tells the computer how cold it is out then the computer determines how rich to make the fuel mixture.

Would that be the air temp sensor or the mass air flow sensor? I was also thinking that it could be the idle air control valve.

Tiny
Iroshiyan
Aug 7, 2009.
The temp sensor identifies engine temp, and the mass air flow (air intake) identifies the amount of air entering the engine.


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