BUGA Community
Technical => Driveline => Topic started by: nathro V2.0 on January 12, 2009, 11:58:47 AM
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Hi All,
Have recently bolted on all the parts etc and bought a new quadrajet carb from a carby store. Have connected the vacuum advance to the dizzy and blocked off the rest of the ports.
The engine turns over fine and all of the plugs are firing etc.
I can get the engine to run when pouring fuel down the throat of the carby but i cant get it to run on its own. Fuel is being pumped (have taken hoses off and checked). We have adjusted the timing while the engine is running while pouring fuel down it so that is fine.
The only thing i can think of is that the fuel isnt going through the carby. We have adjsuted the two screw on the front of the carby base (which i believe are the mixture screws?) but have had no success.
Has anyone had this problem before or does anyone have any ideas how to resolve this (preferably without visiting a mechanic)?
Any help would be greatly appreciated!
Cheers, Nathan.
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Nathro make sure the filter in the Quadi is clean. It's where the fuel line goes into the carb. Is there fuel in the carb? If the fuel pump is working ok and there is no fuel then it has to be either the filter or the needle & seat or float set wrong.
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You can check the float level in a quadrajet while its running using a paddle pop stick, by sitting it down the slot on top of the float. i can't remember what measurement its supposed to sit at, but if you know someone who has another one you will be able to measure off theirs.
you bought a quadrajet new? im guessing its a recon one? they may have stuffed it up and used a wrong gasket (there are a few types of quadrajets and they have slightly different gaskets, which can cause problems.
the mixture screw will just affect the idle and low speed mixture, so it should still run open throttle no matter where the mixture screw is set.
if you cant see/ hear any fuel squirting down the barrels when you open the throttle up (while not running) it means the fuel bowl is likely to be empty, as the accellerator pump draws fuel direclty from the fuel bowl on a q'jet. in that case the float or needle may be stuck, and its possbile that it was assembled incorrectly. but give it a few solid taps with a screwdriver handle while turning over your engine. sometimes they stick when they're dry and just need a shock to free them up and get fuel in.
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so, my mate was tinkering with it last night and worked out the problem. fuel was being pumped but there was a blockage in the line right before the carby. so when we were taking off the rubber fuel hose to check there was plenty of fuel coming through but then getting blocked in the hose. Even a 100psi hit froom the air compressor wouldnt dislodge it.
after changing the pipe and reconnecting the fuel it ran first time. And it was loud. lol. I think we may need to change the exhuast on it.
THanks for your help guys. Nathan.