Fuel Pressure Regulator (1 Viewer)

[Boaf 32]

LCer's

Posted some notes before and have plumed a Fuel Pressure regulator for my 72 LC with Weber Carb. I do not see any pressure on the gauge, and want to make sure the fuel input and output is installed correctly. According to the videos on youtube (ah Ha ha), the input is correct.

I blow a ton of black smoke out the exhaust and I can smell the fuel, in addition to the 8 - 10 MPG. Let me know what you think, thanks.

Thanks,

Boaf

 

[B y r o n]

I can't make out your fuel line routing from the photo. However, the line coming from the fuel pump should go to the regulator. Then to the pressure gauge and from the gauge to the carburetor. Is that how you routed yours?

 

[Solace in Solitude]

^x2^

I don’t think you have it routed correctly, but can’t tell for sure without seeing the rest of your fuel feed lines.

But, @B y r o n gave you the correct routing.

 

[Boaf 32]

Sorry, thought the picture helped but it doesn't. The line going into the regulator where the dial is (top of photo) is coming from the Fuel Pump. The line on the left of the photo is the return to the fuel tank. I switched them and still no fuel pressure monitor, but I do have fuel going to the return line. Hope that helps, thanks.

I will check vacuum next to make sure the gauge is working.

Boaf

 

[B y r o n]

I have never seen a carburetor setup plumbed with a return line to the fuel tank, only fuel injection setups. Try blocking off the return line and see if you get a pressure reading then.

The regulator is like a water spigot and controls the flow of fuel from the pump. The gauge positioned between the regulator and the carb will give you a reading of the fuel pressure between the two. Pressure will only build once the float has raised and closed the needle against the seat. In my short research it looks like Weber's only need 3 lbs. which isn't very much. With the regulator set correctly it will shut off the flow of fuel to the carburetor until the pressure drops. If you have a return line Tee'd into the line between the regulator and the carb there is no way any pressure will build because the fuel is simply allowed to return to the tank.

I hope this helps.

 

[Boaf 32]

I have never seen a carburetor setup plumbed with a return line to the fuel tank, only fuel injection setups. Try blocking off the return line and see if you get a pressure reading then.

The regulator is like a water spigot and controls the flow of fuel from the pump. The gauge positioned between the regulator and the carb will give you a reading of the fuel pressure between the two. Pressure will only build once the float has raised and closed the needle against the seat. In my short research it looks like Weber's only need 3 lbs. which isn't very much. With the regulator set correctly it will shut off the flow of fuel to the carburetor until the pressure drops. If you have a return line Tee'd into the line between the regulator and the carb there is no way any pressure will build because the fuel is simply allowed to return to the tank.

I hope this helps.

It does Byron, thanks. The pressure comes from turning the Allen wrench screw to a closed position to force fuel into the carb and allow the excess to pass back to the tank. I will update after I check the vacuum. I have a strong suspicion that the carb was jetted to allow more fuel. Will see, being methodical about it.

Boaf

 

[Dizzy]

You can have a T, but there should be a restriction (orifice) to the return. I don't know the size of the orifice. You have a capped float bowl vapor vent, however, that might be a way of addressing vapor lock if you score an appropriate charcoal canister.

 

[Steamer]

I've always found with most any kind of regulator that when the input pressure and the output pressure aren't far apart, the regulator is hard to control and the output is often erratic. When I first put on a Weber, I plumbed in a Holley regulator, a guage and no return. Should of known better but I tried it and it worked like crap. Took out the regulator, kept the gauge, and at idle it maintained about 5 lbs. Ran fine like that for years. I've heard several others here with Weber experience say "loose the regulator".

 

[brian]

I have never seen a carburetor setup plumbed with a return line to the fuel tank, only fuel injection setups. Try blocking off the return line and see if you get a pressure reading then.

.

almost every fj40 here in the states left japan with a fuel return circuit from the carb, with the fj60s return from the pump.

 

[brian]

LCer's

Posted some notes before and have plumed a Fuel Pressure regulator for my 72 LC with Weber Carb. I do not see any pressure on the gauge, and want to make sure the fuel input and output is installed correctly. According to the videos on youtube (ah Ha ha), the input is correct.

I blow a ton of black smoke out the exhaust and I can smell the fuel, in addition to the 8 - 10 MPG. Let me know what you think, thanks.

Thanks,

Boaf

with the tank return, you do not need a prv.

the rich condition/ black smoke and poorer mileage is coming straight from the carb...which should just be replaced.

 

[Boaf 32]

with the tank return, you do not need a prv.

the rich condition/ black smoke and poorer mileage is coming straight from the carb...which should just be replaced.

I like that thinking. It's just too much hassle with this pressure regulator, and the carb that I have no history with, I think the carb was jetted. It can be re-built but why?. So I may just replace the whole enchilada. I already have a plumb to the tank if I needed it. Still checking the vacuum before anything.

Boaf

 

[Boaf 32]

I like that thinking. It's just too much hassle with this pressure regulator, and the carb that I have no history with, I think the carb was jetted. It can be re-built but why?. So I may just replace the whole enchilada. I already have a plumb to the tank if I needed it. Still checking the vacuum before anything.

Boaf

with the tank return, you do not need a prv.

the rich condition/ black smoke and poorer mileage is coming straight from the carb...which should just be replaced.

So I believe my carb is a Weber 38/38. It has the gears for the Primary to Secondaries. As mentioned earlier, I have the fuel mixture closed and it still runs strong.

I would like to hear what other LCr's are choosing for their Webers, 32 / 36? My mileage really is bad. Thoughts from the crowd?

Thanks,

Boaf

 

[brian]

what is that rod fastened to the intake?

 

[Dizzy]

Don't you mean fuel mix screws? There are two of them.

The idle speed screw should be no more than 1/2 turn in from touching, otherwise you are not technically at idle.

 

[Boaf 32]

what is that rod fastened to the intake?

That mounts a power steering pump for pulley alignment.

 

[Boaf 32]

what is that rod fastened to the intake?

It is attached to a Power Steering pump. Keeps the pulley aligned.

 

[brian]

those two piece adapter never did anyone a favor. most times the fasteners for the top were too long by just a thread or two. they would bottom out in the blind holes of the lower plate, far enough in that everything looks tight, but would allow vacuum leaks between the two plates. the weber its self probably needs re-jetted, at least the two idle jets. they were sold in kit form, but they were far from just plug and play.

 

[Boaf 32]

those two piece adapter never did anyone a favor. most times the fasteners for the top were too long by just a thread or two. they would bottom out in the blind holes of the lower plate, far enough in that everything looks tight, but would allow vacuum leaks between the two plates. the weber its self probably needs re-jetted, at least the two idle jets. they were sold in kit form, but they were far from just plug and play.

Thanks Brian!