Gas Tank Vent line

[MalibuRacing]

OK, I have a few questions.

First, do I need to run a special gas cap when doing the EFI conversion, or just the stock '79 gas cap?

Can you just plug the vent line or does it need to be allowed to "breathe"?

The reason I ask is that I tested the in-tank pump this weekend. Right now, I just have a piece of hose hanging down (temporary) for the vent line. When I turned on the pump, it started shooting fuel out of the vent tube. I'm 99% sure I have everything connected properly. The output (feed) line already had a special fitting on it to distinguish it from the return or vent lines. Any ideas why it would have shot fuel out of the vent line?

 

[Marco2]

From my research a vented gas cap and a small breather on a short line attached to the vent is all that is needed.

 

[MalibuRacing]

Wonder what could have caused fuel to shoot out of the vent hose? Is the stock '79 cap vented or not?

Here's my setup:
1979 Malibu
1987 Monte Carlo EFI tank
1987 Monte Carlo EFI sending unit and pump hanger
High pressure in-tank fuel pump

Picture of setup how I have plumbed:
Top is output line
Middle is return line
Bottom is vent line

 

[454RAT]

maybe the vent is supposed to be the supply and supply the vent?

N/M just seen the made in canada sticker, that explains it............................. jk

 

[StreetBu]

You have it set up correctly, the top is the pressure, bottom is the vent. I just went and looked at mine I have no idea why that would be happening. Is the tank sitting level(according to how it sits in the car), how much gas is in it? There shouldnt ever be gas as high as the vent when the tank is installed in the car, the filler pipe enters lower than the sender and allows for an air pocket at the top of the tank. Hence, air around the vent.

 

[455_82malibu]

you must be pressurizing the tank , try it without a gascap. I had to drill a 1/8" hole in my cap

Id cap off the vent and run a vented cap. All I have is an inlet and return and drilled cap

 

[MalibuRacing]

you must be pressurizing the tank , try it without a gascap. I had to drill a 1/8" hole in my cap

Id cap off the vent and run a vented cap. All I have is an inlet and return and drilled cap

Thanks. I believe that may have been the problem. I don't have a cap installed. I have a "plug" inserted in the filler neck that came with the tank when I bought it new, so that is most likely the culprit. It caused an air-tight seal of the filler neck. My old gas cap was mangled, so I need to get another one anyways.

 

[RatMalibu]

I'm curious about the blue AN adapter...is it a oring seal to AN adapter? AN6, and whats the part number and where'd ya get it? I'm getting ready to switch to electric and need to figure out the best way to hook it all up...

 

[MalibuRacing]

I'm curious about the blue AN adapter...is it a oring seal to AN adapter? AN6, and whats the part number and where'd ya get it? I'm getting ready to switch to electric and need to figure out the best way to hook it all up...

Yep, Earl's 9894DBJERL adapter, -6 AN Hose End to 16mm x 1.5 Female. Got it at SummitRacing. See here: http://store.summitracing.com/partdetail.asp?autofilter=1&part=EAR-9894DBJERL&N=700+115&autoview=sku

Here's the link to my swap that has the EFI fuel tank/sender information: http://www.maliburacing.com/forum/viewtopic.php?f=34&t=72148

 

[Doober]

I think I missed something about the fuel lines from the beginning... why did you need the adapters again? I'm going with a stock EFI tank/sender when I do mine, but I'm replacing all the hardlines with lines from Inline Tube.