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Discussion Starter #1
A few days ago I started the 428 car. Once it fired it wasn't but about ten seconds until it started running rough and died. Upon checking the engine I noticed the carb had fuel coming from the rear bowl overflow and also the front hole in the metering blocks. I checked and cleaned the shutoffs and the problem is still there. I'm now wondering if the fuel pump which is stock and original is putting out too much pressure and forcing the seat valves open and causing the overflow. Also I checked the floats and they are OK. Not sure what regulates the pressure in these old mechanical fuel pumps but there has to be something. Anyone else had this issue and how did you solve it. I don't have a fuel pressure gauge but may be able to rig something up.
 

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It's possible, but if it was running fine last time and has been sitting it's more likely the needle and seat assembly if you have a Holley carb. It's usually not the needle itself but the o-ring around the assembly gets dried up and gas just runs past them. They will look flat rather than rounded. They can also be damaged when you install the assembly if you are not careful. The pump is regulated internally. Original pumps you can take apart and rebuild.
 

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+1 very similar to a toilet that keeps running.
 

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Thanks, I took the needles out and they appeared to be OK. Also took the bowls off to make sure there was no dirt in them, they was clean. I cleaned the needles with carb cleaner and used air to blow into the little ports, after that I blew into them to make sure they were sealing. They "appeared" to be OK. I'll order another set of them just to make sure. On the rebuilding the fuel pump, where can I get the kit. I have a "X" pump as well as the original on the 428 CJ I'd like to rebuild. OH, it's a Holley 4168 on my KR. Thanks.
 

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The fuel pump pressure is "regulated" by the float and valve in the carb. If there is fuel coming out the overflow ports, then the float/valve aren't shutting off the fuel (or the float setting is too high). Or the check valves in the fuel pump might be sticking. Check the deadhead pressure on your fuel pump to see if it's beyond specs.
 

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If you have the needle assembly out just replace the o-rings. I always get the ones rated for alcohol fuels they seem to last longer with the ethanol in the gas. New needles will be fine also, put a smear of Vaseline or o-ring lube (you can get that at hardware stores in the plumbing section) on the o-ring before putting the assembly in the bowl.


there are other places you can get a Carter rebuild kit but that one will have everything you need.
 
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