Need help fuel in oil

[dmanblazer]

My engine is full of fuel,and I think it did it overnight and I'm thinking it is a bad fuel cap. When I take off the fuel line to the carb, fuel just keeps pouring out of the line when I loosen the cap it will stop and there is always presure behind it. I've removed the charcoal cannister but still have my overfill hooked up to the tank.
When I first built the engine I tried to use a Qjet I had and it filled the engine then so I thought it was the carb being dirty so I got a new Edelbrock AFB and it didn't do it again, but now I tried to put a new reman Qjet on it and it filled it again. Whats up?

 

[78Suburban]

I'm no expert, but there are 2 possible causes I've heard on here. It could be a leaky fuel pump diaphram. It could also be fuel draining down from the carb if it has leaking internals (somebody put some technical wording to what I just said please)...

This may not help, but at least it sent your thread back To The Top
thanks,
James

 

[dmanblazer]

i put a new pump on it the first time it did this,the well plugs on the carb have been epoxied

 

[dmanblazer]

Thanks for sending my thread back to the top LOL

 

[86haubs]

I am no expert either, but the fuel pump is the only thing that makes sense to me also. The fuel from the fuel lines going into the carb only come from 1 place, the pump. It is an easy swap so I would give it a shot. I am not sure, but if that fuel is filling up your oil pan I would pay close attention to you valve guides/seals, they will get eaten up.

 

[1-ton]

If the fuel is coming from the carb, then it may be the float level is adjusted too high. If the float adjustment level is to high, then this will allow fuel to over fill the float bowl.

 

[dmanblazer]

On the bottom of my fuel pump is 2 connections, 1 is for the feedto the carb the other is for the overflow back to the tank ( I think ) so I have the 2nd one hooked to the fuel return is this right? So what I'm thinking is the tank is building pressure from the over flow and causing the needle to lift from the seat when the truck isn't running, that's why I think it is the cap isn't it suposed to vent

 

[hack500]

also if the oil gets diluted too much the oil will not do it's job of lubricating everything - 'specially bearings.

if you just have 2 connections on your fuel pump you don't have a return line.
is it a stock pump or a "high volume"? if the fuel pressure is too high for the Q-jet it will cause internal leaks. iirc, a Q-jet will only be happy at 5-7psi or less.

 

[dmanblazer]

let me clairify one from tank to pump, one from pump to carb and a 3rd fitting that I think is fuel return

 

[diesel4me]

plug it..

I'd remove the "3rd" return line hose,and cap the fitting on the fuel pump,if you ditched the vapor canister..you don't want to be pumping fuel back to the tank if it has nowhere to go..the vapor canister used to releive the excess vapors and pressure..
I assume the hose that went to the canister was plugged off when it was removed..now the gas has only one escape..thru the carb!..and you motor will not last long if you run it like that --it will "gas wash" the oil off the rings,and bearings will suffer too..change the oil right after you fix the pump..and the filter!..all kinds of slugde gets loosened up from the solvent action of the gas..not good!..

Leaving the gas cap loose might help,until you fix it right..but I wouldn't run it with diluted oil very long..

Maybe switching to a "normal" pump with just 2 lines,like a 40987 AC would be a good idea,just in case the diaprhram IS ruptured in your "3 hoser"..
I have one on my 305 with the return line blocked,it seems ok..but I have seen some Q-jets overflow when you do that..hasn't bothered my Edelbrock yet..

 

[dmanblazer]

Thanks for all the help guys, I figured it out.

 

[resurrected_jimmy]

I figured it out.

Now you have to share with the rest of the class

 

[dmanblazer]

Well I left the cap off and it hasn't done it yet, it also runs better, but I haven't gone to far yet if it does it again I'll reopen this thread let ya'll know?