ok had a 92 rs v6 pulled it out and out and put in a built sbc 406 carbbed and im using the factory fuel pump with a mallory return style regulator. if the car sits for than a day it will fill the cyl with fuel and eventually the pan to... im at a lose for waht todo... i thougth it may have been the carb so i rebuilt it and it still did it so i bought a new one and still having the issue... recently is back fired horribly when i turned the engine of and it blew the oil pan gasket out from between the pan and block so im kinda lost as to what it could be.... i figured it could be siphoning fuel from the tank but i dont see how it would push past the carb floats.... i have a fuel pressure guage on the dual feed for the carb and a autometer fuel guage offf the regulator and then i kill the key the pressure drops to 0 so i dont think it is residual pressure either... any had this issue or have any idea on what is goin on?

 

No1 has any input or ideas??? Idk what todo....

 

Fuel pump not shutting off? Did you run the relay jumper wire to run-hot only? Did you use the OPSU switch? What kind of FP are you seeing with it running? I assume you checked to make sure the return line bleeds off pressure well enough like in the instructions of the regulator.

 

Did you adjust the floats properly? Sounds to me like it's loading up way too much.

 

Are you using a mechanical pump as well?

 

I'm using the factory electric pump. With a Mallory return style reglator. The car runs and drives fine! It's not a carb issue. The pump isn't tuning it is word thru a relay and only has power with the key on. It won't do it if I pull the fuel line off the carb and let it sit.... No fuel will come out of the line and the ffuel bowls in the carb stay full. I have checked all the obvious things.... I thought about all day at work today... And I have only come up with one possible senerio... I think the fuel tank vent is clogged..... I think that in the heat the fuel vapors build and create pressure forcing fuel up the feed line over pressuring the floats forcing fuel into the cylinders. That would explain why It dosent flow fuel out of The feed line when I leave it off... It acts a tank vent... Sound plausable?

 

In that case wouldn't leaving the gas cap loose or switching to a vented cap be an easy way to check if it's due to the vent?

 

Indeed I plan on doin that asap. I have the oil pan off replacing the pan gasket I should have it togather hopfully tomorrow. And I will try it and post back results.

 

ok well i think removing the gas cap fixed my problem... so one down one togo... i have another question and i hope yall can help.... the car runs and drives fine but was back firing... and it didnt start doing it till i ran a pcv valve. so i removed the pcv valve and just ran 2 breathers and it stopped the back firing... but it blows oil out the breaters... any1 have any ideas?

 

A little smoke coming out of the breathers is normal IF there is no PCV value. Oil blowing out could mean excessive blowby on the rings. A compression check could troubleshoot that.

 

Was my first thought... The motor is pretty much new but I checked them anyway... They were all good... It blows no oil out when I run a single pcv valve but I causes bak firing.... So I'm insure what it could be.