No, install it in the supply line.

Yeah, I found some that have the return built in. I guess fuel pressure is supposed to be around 4 lbs, and my FSM says the stock pump (if that's what it still has) has an output of 2-8. That could be why its leaking inside when I shut it off maybe.

 

I'm going to order the weber redline regulator and install it inline with a gauge. Seems to be the best option I think.

Too much fuel supply isnt going to flood it when its off though. Unless its so bad that the carb is flooded all the time, on or off.

Id get a power valve too.

OK, small updates. I ordered a standard jet kit from redline as well as new intake manifold gaskets from Subaru (I am just not trusting the felpros that are on there now).

 

I also checked my fuel pressure and it is at 1.5-2 PSI. I am not sure if that is enough or if I need a fuel pump. I have read Webers like 2-4 PSI. I have the Holley fuel pressure regulator (not installed). Should I get the Redline fuel pump then use the regulator to send 3-3.5 PSI to the carb?

 

My power valve is brand new, but the full power valve it pushes has been ordered. I also read that the pump delivery valve that holds the accelerator pump jets can stick causing fuel to escape as well, so I ordered that too.

When all is considered the float operates the fuel cutoff in the needle and seat assembly purely from the pressure applied by fuel lifting the float up, Somehow I doubt the different carburetors all need a different fuel pressure what works for a Hitachi should be fine for a Weber or a Holley or any other type of carburetor.

 

The real problem requiring a Fuel Pressure control system for carburetors is that some pump manufacturers think you need or want more fuel pressure and make their pumps too powerful in that area, Why who knows if for instance you run a Big Horsepower V8 with twin four barrels that will not need more pressure from a pump , Maybe more volume but not pressure.

However one thing does apply lots of volume into a restriction can cause a rise in pressure hence why many factory systems do use a return line that allows excess volume to bleed off so keeping the pressure under control.

 

Note that Subaru themselves have that fuel return line for exactly that reason to allow excess fuel to bleed off and keep pressure at a controllable level that then stops the carburetor from flooding.

Edited February 28, 201511 yr by coxy

When all is considered the float operates the fuel cutoff in the needle and seat assembly purely from the pressure applied by fuel lifting the float up, Somehow I doubt the different carburetors all need a different fuel pressure what works for a Hitachi should be fine for a Weber or a Holley or any other type of carburetor.

 

The real problem requiring a Fuel Pressure control system for carburetors is that some pump manufacturers think you need or want more fuel pressure and make their pumps too powerful in that area, Why who knows if for instance you run a Big Horsepower V8 with twin four barrels that will not need more pressure from a pump , Maybe more volume but not pressure.

However one thing does apply lots of volume into a restriction can cause a rise in pressure hence why many factory systems do use a return line that allows excess volume to bleed off so keeping the pressure under control.

 

Note that Subaru themselves have that fuel return line for exactly that reason to allow excess fuel to bleed off and keep pressure at a controllable level that then stops the carburetor from flooding.

So the Subaru Carburetor has a pressure control valve (device) built into it if it has a fuel returning line, Correct?

So the Subaru Carburetor has a pressure control valve (device) built into it if it has a fuel returning line, Correct?

 

 

no, it has a standard float just like any other Carb. When the needle valve is closed, the fuel will just return to the tank, as the float drops opening the valve, the fuel flows back into the bowl to refill it.

Great, iluvdrt, thanks for the explaination.  I'm looking forward to your getting through this problem, did you get the Redline regulator installed yet?

 

"I'm going to order the weber redline regulator and install it inline with a gauge. Seems to be the best option I think."  (#27)

Great, iluvdrt, thanks for the explaination.  I'm looking forward to your getting through this problem, did you get the Redline regulator installed yet?

 

"I'm going to order the weber redline regulator and install it inline with a gauge. Seems to be the best option I think."  (#27)

 

I got the gauge and everything. I ended up going with a Holley regulator 1-4 PSI. After installing the gauge, I am only getting 1.5 PSI of fuel, so I ordered the Redline fuel pump. That hasnt arrived yet. 

 

So for the next week I am removing the intake manifold and porting it mildly to get better flow off of the adapter plate, checking all of the jets and tubes in the carb and setting it back to OE spec (mine is high altitude), using genuine Subaru gaskets, and installing the redline fuel pump with the holley regulator.

 

If that doesn't fix it, .....EJ22 swap lol

OK,

 

I took off the Carb and intake manifold last night. It looked like whoever rebuilt the Carb before me installed all of the jets and emulsion tubes like a DGAV, not a DFEV (which is a mirror opposite). So what that means is that basically everything was backwards. The jets were also considerably smaller than what the OE spec calls for. It had a 130 jet in the primary and a 137 in the secondary. The emulsion tubes were 160/155 and the idle jets were on the wrong sides although they were the correct size.

 

I installed a 150 jet in the primary and a 145 in the secondary, a 180 primary emulsion tube and a 170 in the secondary, a dual nozzel jet, and swapped the idle jets around to match the primary and secondary locations according to the weber listing for the DFEV Carb. I am still waiting on my needle valve for the power valve assy, as well as the banjo bolt for the jet nozzel (which did not have the check valve installed).

 

I should also be recieving my Redline fuel pump in a few days as well. I should have some results to post up by this weekend.

Well, its fixed and runs amazing! I ported the lip where the flange and adapter is to make it a smoother transition. Changed the needle valve the power valve operates, installed a dual nozzel jet with new banjo bolt, the main jets are 145/140 and the emulsion tubes are 165/160. I also pulled out all unused vacuum tubes from the manifold, drilled and tapped them out to fit 1/8 brass pipe plugs with JB weld. I made a EGR block off plate and installed it with JB Weld also. New Subaru intake manifold gaskets and that wrapped it up.

 

I'm still going to install the redline fuel pump, holley fuel regulator and fuel return valve this weekend, but for now she's running darn near perfect and not leaking fuel anymore.

 

Thanks for all of the help. I'll drop a line once the fuel pump is in with the regulator and return.

I went ahead and installed the Weber Redline fuel pump and Volley FPR. I cranked it to 3 PSI and things got even better. This is such an amazing set up, I can't thank everyone enough for the help. I'll post pics soon, my Brat is almost showroom quality lol. 99% rust free and just minor door ding dents a 33 year old car would have. That is for all of the help!

Edited April 23, 201510 yr by iluvdrt

Could you post part numbers for the Redline Fuel Pump you used and also for the Holley FPR?

Good deal, glad you got it running right

So, with some tuning I FINALLY got it running great. But whenever I make a hard right hand turn it wants to stall out. I am thinking its because the fuel pulls away from the jet. My float is at 42mm, and there is no way the redline pump is running out of steam. Fuel pressure is 3.5 PSI. 

 

Any ideas how to fix that?