I'm pulling my hair out over this one...

I've got a 390 with a 2 barrel intake and a holley model 0-4778 carb...
The carb is 6 months old....

Here's the full story...my gas gauge just stopped functioning last week...so I ran out of gas... since then things have been going down hill...

I've searched all the forums and checked the fuel pressure by putting a pressure gauge right before the carb, its reading a steady 6 psi so I don't think the fuel pump is the culprit...


The carb started leaking gas into the crankcase..I checked the float level, cleaned out the needle, and replaced the power valve in the carb...then drained the crap oil/gas and put in a new oil filter and oil...

Then started her up for 2 minutes and she does it again....all kinds of gas in the oil...f^&*ing pissing me off!! I've gone thru this about 3 or 4 times now and I've spent so much $$ on oil and oil filters trying to figure this bitch out...

I am now going to tear the entire carb apart and soak it in carb cleaner and if this doesn't work I'm switching over and buying a new Edelbrock...

Before I spend any undue cash, does anyone have any ideas or suggestions on why this carb is pissing into my oil?????

thanks guys

 

Change your fuel pump, sounds like the diaphram has a hole in it and its pumping into the crankcase as well as the carb. and put new filters in the line, one before the fuel pump and a new one before the carb, when you ran empty it probably picked up something from the tank and it would be best to keep it out of the carb if possible..

 

Your running a 700 double pumper on a 2bbl intake???

I agree with the fuel pump. The carb would have to be flooding terribly to to that.

 

X2 here;

That carb on that intake will NEVER work well.

But that is not the problem you are asking about. There is NO way for fuel from your carb to leak into the crankcase. It is the fuel pump, replace it, change your oil and you should be good. Except for the manifold anyway.

 

hey guys, thanks for the advice. I think I wrote the wrong carb model number...its a 2 barrel model 2300 carb, 500 cfm part number 0-4412C...heres the link to it Holley Performance Two Barrel Street Products, its not a double pumper...should this carb be allright?

It was running excellent before this...

Anyways, I spent the afternoon replacing the fuel pump as advised and now that I think about it, I'm almost certain that this is where the fuel was getting into the crankcase.

The reason I'm pretty sure of this is because I ran the truck for about 5 minutes and afterwards pulled the carb off and looked into the manifold and there wasn't any pools of gas like I'd have expected...

I got a quick rebuild kit for that carb just for good measure...I think I'm in the clear again, thanks for the help!

 

I've been reading on this site about priming the mech. fuel pump before installation.

It didn't mention the necessity for this in my haynes manual or in any instructions that came with the pump...and I couldn't figure out how to do it anyways...so I installed the new fuel pump without priming it..

After I reinstall the carb, if I pour some gas down the throat and try starting it, will the vacumm be enough to get that new fuel pump pumping???

 

Yes, the best thing to do is to pour a shot glass worth of fuel down the bowl vent to fill the bowl so it will run well enough, long enough to get things going.

 

The pump will draw fuel without priming. It is mostly gravity fed anyway.
So yes, pour a little down the carb and it should take off after a time or two.
The 4412 is a good carb. A good choice for your engine.

 

she started right up first crank! and no more gas in the oil, so it was the fuel pump leaking.

Got her all tuned up again and she's running like a champ! thanks for all the help
This website is an incredible resource to guys like me who are new to tinkering on these trucks! thanks for all the help

 

Good to hear!!! Merry Christmas

 

The inside of that engine ought to be REALLY nice and CLEAN!!!!

 

Glad to hear that! If you changed the oil when you were done all should be good for a long time now..

 

This is fords automatic crankcase flush.happens all the time,about only way to know the fuel pump is going.check that oil often,that thin overfill got to be hard on bearings,reg