# dry carb



## 68GTO4004Spd (Jun 19, 2008)

Whenever I leave the car sit for a couple of days, I have to pour a little gas in the carb to get it running (as opposed to cranking and pumping the accelerator until it eventually starts, hard on the starter and batt.). I rebuilt the carberator (stock Q-jet) with all new gaskets, didn't fix the problem (runs better though). Any ideas on what this may be? Some direction would help.


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## freethinker (Nov 14, 2009)

68GTO4004Spd said:


> Whenever I leave the car sit for a couple of days, I have to pour a little gas in the carb to get it running (as opposed to cranking and pumping the accelerator until it eventually starts, hard on the starter and batt.). I rebuilt the carberator (stock Q-jet) with all new gaskets, didn't fix the problem (runs better though). Any ideas on what this may be? Some direction would help.


there are 2 little plugs under the carb base that were well known for leaking back in the day.


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## Jerry64 (Apr 20, 2010)

If you rebuilt it recently,the kit should have came with 2 rubber blocks.Those are to put in the cavity where the well plugs sit to seal them.......Gas evaporates out of a carb in a short time with the fuel standards of today.After it sits for a few days,pop the air cleaner and take a flashlight and look in the carb and see if gas squirts from the accel. pump before starting it.Also check the choke settings........JB.


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## geeteeohguy (Feb 2, 2008)

The above two posts hit the nail on the head. The well plugs will leak over time, and give you the problem you are experiencing. JB Weld is what I've always used. I didn 't even know about the rubber plug fix! Any Q jet will go dry after sitting more than a week or two with todays volatile fuels.


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## 68GTO4004Spd (Jun 19, 2008)

Hmmmm interesting, where are these plugs located? How big in diameter are they? Will I be able to reuse the base gasket if I take the carb off? Thanks for the replies.


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## Thumpin455 (Feb 17, 2010)

Well the right way to fix the plugs is to disassemble the carb, drill the plugs then use a bottom tap to put threads in the holes. Seal with with ultra black RTV on the threads, but not a glop of it in the well, it will plug the main jet passages. Blow all the chips out from tapping, and reassemble the carb.

An electric pump would allow you to prime the carb prior to cranking, thats what I use. All of mine sit for months at a time so even the Holleys go dry.

This is what we are talking about.










Here is the thread on another Oldsmobile forum that had the info.
Realoldspower.com :: View topic - quadrajet tuning questions


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## harp (Jun 22, 2009)

sounds a little like my 69 before i found the pin-hole leak in the steel gas line. patched it up and it starts every time, and doesn't cut out at higher rpms.


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## Richard Boneske (Jul 29, 2008)

All the GTO carbs, Tripower and Quadrajet, had the fuel bowl vented to atmosphere through the air horn casting. It takes only a few weeks for the fuel to evaporate from the bowl, so it takes a lot of cranking to start the engine. 

On your Quadrajet, the other posters are right on about the two wells leaking. Correcting that is an easy fix and really common on early Quadrajets. They're great carbs once this is fixed. 

The comment on today's fuel evaporating faster than "back in the day" has no validity. The volatility (evaporative properties) of today's gas, even if it's with 10% ethanol, is no different than it ever was. Gasoline is blended different in summer and winter, however. In winter, more volatile additives are used.


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## dimitri (Feb 13, 2009)

Sounds like the diaphram in your mechanical fuel pump is getting old. It will have presure while the engine is operating but when it is off, it is supposed to act like a check valve.

Dimitri


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## BillGTO (Oct 16, 2009)

Check that your rubber fuel hoses are 'nt dried up and brittle. They will also leak air and allow fuel to drain back to the tank.


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## dimitri (Feb 13, 2009)

BillGTO said:


> Check that your rubber fuel hoses are 'nt dried up and brittle. They will also leak air and allow fuel to drain back to the tank.


I was replacing my fuel lines every year. I am now using high pressure fuel line they sell at Napa in bulk. It is a little more expensive. It has a teflon liner that does not break down to oxiginated fuels. 

Dimitri


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## 68GTO4004Spd (Jun 19, 2008)

billGTO Yeah I replaced the fuel lines, they were brittle.
Dimitri, can the diaphrapm be replaced or do you have to replace the whole pump?
Thanks for all the replies, now I just got to get my lazy azz out there and work on it.


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## dimitri (Feb 13, 2009)

Pumps are not rebuildable. Make sure to use a 5/8" line wrench and a 3/4" open end wrench on the steel line fittings. The 3/4" is for the pump. Put a small amount of assembly lube, or white lithium grease, on the new pump arm where it rides on the eccentric. Make sure when you put the new pump in that the arm goes under the eccentic. This would be a good time for you to replace the fuel filter in your carb. 

Good luck,
Dimitri


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