GAS PIG - WHERE TO START?

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Ted S. Mruk

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Oct 29, 1996, 3:00:00 AM10/29/96
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We have a 1983 GMC 4X4, it has been babied since new and has low
mileage. It always was a bit of a gas guzzler but recently it has
just completely gone mad. It takes a tank of gas to go 120 km.

It has a 305 V8 in it and seems to be running just fine. Lots of
power, idles nice, starts fine but just uses fuel excessively. There
are no leaks that we can detect and the gas cap fits fine.

Where should we start looking for answers to the problem? Any advice
would be appreciated.

Thanks in advance.

Ted


Kirk McGraw

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Oct 29, 1996, 3:00:00 AM10/29/96
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Check to see if it is running rich. Pull the plugs and if they are
black and sooty instead of tan, you are running rich.

If you are too rich, check the temperature sending unit, choke
and the like.

Kirk McGraw

John Stone

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Oct 30, 1996, 3:00:00 AM10/30/96
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Ted S. Mruk (tsm...@elcocomp.com) wrote:
> We have a 1983 GMC 4X4, it has been babied since new and has low
> mileage. It always was a bit of a gas guzzler but recently it has
> just completely gone mad. It takes a tank of gas to go 120 km.

> It has a 305 V8 in it and seems to be running just fine. Lots of
> power, idles nice, starts fine but just uses fuel excessively. There
> are no leaks that we can detect and the gas cap fits fine.

> Where should we start looking for answers to the problem? Any advice
> would be appreciated.

I don't recall if this had one of their electric carbs on it or
not.(ie EFI engine;) If it is EFI, I would immediately replace
the o2 sensor even if the service engine light is not on. I
fought this problem during smog time for an 86' S10 Blzer...
no engine light, no codes, nothing... it just ran rich. Turns
out the o2 sensor got stuck open and the EMC doesn't read this
as being wrong.

Drew Clary

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Oct 30, 1996, 3:00:00 AM10/30/96
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Ted S. Mruk wrote:
>
> We have a 1983 GMC 4X4, it has been babied since new and has low
> mileage. It always was a bit of a gas guzzler but recently it has
> just completely gone mad. It takes a tank of gas to go 120 km.
>
> It has a 305 V8 in it and seems to be running just fine. Lots of
> power, idles nice, starts fine but just uses fuel excessively. There
> are no leaks that we can detect and the gas cap fits fine.
>
> Where should we start looking for answers to the problem? Any advice
> would be appreciated.
>
> Thanks in advance.
>
> Ted

Do you live in a Reformultaed Fuel state? Here in California, the new
fuel introduced earlier this year is responsible for decreased milage.
--

____________
/ || \\ Drew Clary
_______/[]___||______\\# 1973 Bronco
| ___ | =| o___o |# KD6VBM
[|_// \\|______|__// \\_|] Lathrop, Ca
( @ ) ( @ ) http://www.chevron.com
\_/ \_/ mailto:cl...@chevron.com

The opinions expressed are mine and are not
intended to represent those of Chevron Corp

Mark Wright

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Oct 30, 1996, 3:00:00 AM10/30/96
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k-mc...@cecer.army.mil (Kirk McGraw) wrote:
I had a similar experience with a 76 Ford F-250 with a 460. Thing ran
great but the milage took it in the shorts.

Turned out to be an obstruction in my exhaust system, a baffle had
come lose...

A new muffler brought my milage back to the previous 9-10 mpg!

>tsm...@elcocomp.com (Ted S. Mruk) wrote:

>>We have a 1983 GMC 4X4, it has been babied since new and has low
>>mileage. It always was a bit of a gas guzzler but recently it has
>>just completely gone mad. It takes a tank of gas to go 120 km.

>>It has a 305 V8 in it and seems to be running just fine. Lots of
>>power, idles nice, starts fine but just uses fuel excessively. There
>>are no leaks that we can detect and the gas cap fits fine.

>>Where should we start looking for answers to the problem? Any advice
>>would be appreciated.

>Check to see if it is running rich. Pull the plugs and if they are

jfo...@ionet.net

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Oct 31, 1996, 3:00:00 AM10/31/96
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how about some detail of the engine? EFI? Q-jet? or what

3000 mile screwdriver with no details

jim


cry...@aol.com

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Nov 12, 1996, 3:00:00 AM11/12/96
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Your first problem is the 305 , (no horsepower) take a cranking
compression check.If you don"t have at least 165lbs. you are not making
much power. Step up to a 350 with 10:1 and an rv camshaft
and you"ll be happy with the results. Good luck.

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