Fuel line vapor lock!!

[baja_driver]

just put a new fuel pump on my 5/16 car...everytime I turn the car off and let it sit for a few minutes the fuel line gets a vapor lock...have to crack the fuel line near the pump and release pressure..then it starts and runs fine until I turn off again. bought new fuel pump to try this eve and have electric back up..but have to bypass mechanical pump to run electric..amyone ever see this probelm before??

[FullsizeFun]

I had a similar problem.
I tried to set up my car with 2 electric pumps inline with eachother. I figured i could run 1 at a time and 1 for backup. I thought that there should be no problem pushing/ pulling through another pump. But for whatever reason it didn't pump, I even turned them both on, still nothing. Then tried a big Holley Blue pump after both the other facet pumps, nothing. the fuel cell was full, and vented, I even tried to pressurize the fuel cell with a little compressed air, nothing. Finally i just ran one pump and it is fine.
??????????????

[baja_driver]

I have been running this setup for 3yrs...and had to replace the mechanical pump because a fitting was stripped. now I have the new style pump(brazilian) and have the problem....my engine builder has not heard of this problem before either.

[baja_driver]

looks like I found the answer...seems my oil lines and fuel lines run right next to each other...when the car is running the fuel is flowing and no problem..but when I turn it off...the oil might be heating the fuel in the line causing the vapor lock...will re route fuel line to previous and make sure they are seperated and see if this fixes problem. thanks Dan !

[KitRacer]

I'm not sure I know exactly what you are saying, but I still have a suggestion for you. ORW sells two kinds of mechanical fuel pumps. One you can blow through when it is not operating, and one you cant. Try getting a blow through mechanical pump, that could fix your problem

[Racbaja]

Here is another one for you. At the last coalition race I ran my electric pump as my primary and it took a dump, so I routed into my mechanical and everytime we stoped at a check point the car would load up and die. The problem was when I went directly into the mech pump I bypassed the fuel regulator and it was pumping with too much pressure (pump rod too long?). I am going to play with it a little and do a pressure check to see WTF.

[ntsqd]

I run an electric and a mechincal pump in series on my 'glas buggy. The Facet pump sits under the bug fuel tank in front. Neither has any trouble keeping the engine running. The mech. can pull thru the electric pump and the elec. can push thru the mechanical pump.

The only way that the mech should be a problem is if you plumbed it backwards. The check valves in it should allow the Facet pump to push fuel thru it. While possible, I can't say I've ever seen a mech pump that wouldn't allow this.

I dimly recall that some mech. pumps have their inlet on the bottom and some have their inlet on the top. Blow thru the pump. Which ever bung allows free flow is the inlet.

[baja_driver]

the two types of pumps , would they also be the generator type and the alternator type...the gen style is taller than the alt style but that was the only option they told me when I was there....pressure was fine when running.but also liike you said , my electric would have to bypass this mechanical pump if the mechanical failed...not a flow thru type...the old style pump I had , ,the rebuildable type was flow thru.

[powerbox_builder]

The flow through pump is #113 127 025D and must be Brosol brand. Not Bocar. It is a yellow box with a blue bottom. It takes a long push rod. If you use an electric pump also, then you should use this pump. You can run both at the same time but it is not necessary. The stock pump pulls better than a facet and will deliver plenty of fuel for most single Webber apps. Let alone a 30Pict.

[baja_driver]

I knew I could eventually get the answer I needed....not sure why the sell the other to race drivers , knowing that is the setup we use. got one on order and looking around town to see if anyone has it in stock.