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Old 05-21-2009, 08:43 AM   #1
jojo
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Truck starts right up but...

Ok so when I turn the key, the truck starts right up.

But in less than 10 seconds it dies out unless I give it some gas. But as soon as I stop reving it, it will die out again quickly.

Anybody know what's my problem?

I have only had the truck for about a week but, I know that the transmission has a bad leak and it appears that there is a seal for the carb that is leaking as well. Could either of these things be the problem?
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Old 05-21-2009, 08:55 AM   #2
68gmsee
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Re: Truck starts right up but...

Usually if it starts but doesn't continue running is caused by running out of fuel. Either leaking, clogged filters, float adjustment or not enough fuel going into the carb.

I'd start by making sure your filters are not clogged and then check to make sure the fuel pump is giving the carb enough fuel.

Disconnect the line going to the carb insert it into a plastic container and have someone crank the engine with the distributor disconnected. There should be a strong pulsing stream of fuel coming from the tank.

If all that looks good, then you need to check the carbs float adjustment and insuring it's clean inside. Lots of years can cause gunk to build up inside.
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Old 05-21-2009, 09:07 AM   #3
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Re: Truck starts right up but...

possibly water in the gas. I might try running a can of dry gas through it.
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Old 05-21-2009, 08:42 PM   #4
jojo
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Re: Truck starts right up but...

Some follow up,

I looked at the fuel filters (there's a big one inline between the fuel pump and the carb, and the one inside the carb) both were real bad. I guess there's 2 for a reason.

Replacing them fixed the problem. Tomorrow I'll see about the seal on the carb that's leaking.
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Old 05-21-2009, 09:59 PM   #5
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Re: Truck starts right up but...

Quote:
Originally Posted by jojo View Post
Some follow up,

I looked at the fuel filters (there's a big one inline between the fuel pump and the carb, and the one inside the carb) both were real bad. I guess there's 2 for a reason.

Replacing them fixed the problem. Tomorrow I'll see about the seal on the carb that's leaking.
You might need to get the gunk out of the tank. See how long the filters last before it starts running bad. If it's only a few days or weeks, you'll need to flush our your tank. I'm getting by on new filters, but once I move (finally, a garage!), I know I'm going to have to clean out or replace my gas tank. Good luck with the carb!!!
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Old 05-22-2009, 12:06 AM   #6
El Jay
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Re: Truck starts right up but...

My '72 sat for quite awhile before I bought.
It wasn't quite as bad as yours sounds, but I'd change the steel inline filter and it would run fine for a couple of day & then start to act up.

I took the inline filter off and turned it around backwards just to back flush it into a clear container. I couldn't believe the crud that came out of it.....installed another new filter.
I started adding Sea Foam at each fill up, for a couple of weeks, to clean stuff out and I tossed a couple of inline filters in the glove box with a cheap pair of pliers for the spring clamps.
Eventually the the filter changes became more infrequent and it's been doing okay for probably 1 1/2 years now.
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Old 05-22-2009, 12:15 AM   #7
440chevy
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Re: Truck starts right up but...

you have a vaccum leak somewhere, find that first so it will idle then fix whatever else is wrong with it
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Old 05-22-2009, 03:17 AM   #8
Sicmaro
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Re: Truck starts right up but...

your vacuum leak is probably the bad gasket on your carburetor.......
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Old 05-22-2009, 11:00 PM   #9
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Re: Truck starts right up but...

Could also just need the idle screw turned a little to give it more RPM.
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Old 05-22-2009, 11:05 PM   #10
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Re: Truck starts right up but...

To find a vacuum leak leave the air cleaner on the carb and spray carb cleaner around hoses, carb base and the intake. When it revs up a little you have found your leak.
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