carb problems

Hello, Ok In a nutshell i have a fairly high performance 383 stroker (505 HP) and this winter i pulled apart te motor and replaced all of the gaskets, I only drive it about 500 miles per year and have not really had to fix anything for the last 10 years. I put it back together and went for a test drive, the truck started sputtering and the stalled. I got it in the garage luckily and from that point foward it would not start, When I crank it over the carb (then a holley 750) started shoting fuel out of the overflow vents, I adjusted what I could and replaced the needles. This didnt fix the problem, I then changed the fuel pump to t a 5-7 psi 110gph, similar to what it had before. Still not the problem. I the replaced the carb with a new deamon 750 cfm and was sure that this was the problem but to my suprise on the first crank fuel came out the overflow tubes. So now im compleatly lost as to why im having this problem, Is there something im forgetting, or something ive may have screwed up putting the motor back together.Im truley at a loss right now and dont want to burn my house down, I shuld add that the fuel comes out of the overflow tubes about 3 inches high when i try and crank it over. Thanks, chris

Reply to
59Fleetside
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I'm no carb expert, but if it happened with two units, the likelyhood that it is a carb issue seems very low. Is it possible that engine valve timing is off in such a way that there is excessive pressure in the intake (verses the normal negative pressure pulsations that occur when valves open/close at the correct time)?

Does your fuel pump have a return fuel line to the tank that became pinched/crimped during engine installation? Too much fuel pressure could blow your needle off of it's seat.

Toyota MDT in MO

Reply to
Comboverfish

The overflowing carb is due to a malfunction float valve which is what keeps the fuel at a constant level. The float is either stuck or there is dirt or damage causing the needle to not seat properly and form a seal. Dirt in the gas lines seems like a likely cause if it is happening to 2 different carbs. But it could be gummed up float in both if both carbs were left to sit a very long time with gas in them.

-jim

Reply to
jim

That's why there's crap in your fuel. You could have rubber hoses deteriorating, metal lines rusting, whatever. You need to install an inline filter right at the car inlet. The problem is grit getting stuck between the needle(s) and seat(s) preventing the needle and seat valve(s) from closing.

Bet my shop on it.

Don

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Reply to
Don

Thanks don, I have a new in line filter all new fuel lines, dumped the tahk and put new gas in it already? During the rebuld that was all done.

Reply to
59Fleetside

Is the line AFTER the filter clean?

Don

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Reply to
Don

I find on old Jeeps the crud is in the gas line between the filter and carb. If this doesn't get cleaned well, the carbs have recurring float troubles like you describe.

The gas line on the Jeeps has a dip just before the carb. When the Jeep sits, the gas evaporates and all the crud collects in this dip. A ream out with a wire and rag soaked in carb cleaner something like a gun cleaner gets an amazing amount of junk out.

I also find the 'new' gas mixes are really really bad for leaving a varnish like crud which glues up the float needle and gums up it's seat so I have to take my float and needle out every year or so and clean the sucker or replace it.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06
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Reply to
Mike Romain

Reply to
59Fleetside

Sometimes Mud Daubers take up residence inside a roll of bulk fuel line. Seriously!

Don

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Reply to
Don

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