Weber 40 IDF is dripping Options

[malcolm2]

maybe the holes in the side of the valve body are an upgrade. I saw others like that when I was looking to buy.

[malcolm2]

I finally had time and the temp was good in the garage, to work on this.

Got the floats re-set and new top plate gaskets.... coated with some chap-stick. Took a drive around the neighborhood and it ran great....

Re-check for drips and pools in the barrels and saw none. Rechecked this morning, so more than 12 hours and no drips.

Viton did the trick.

[malcolm2]

new question here tho.....

anyone use a QFT pressure regulator?

This one is giving me trouble. At first I could not get it to go down...... Now I can't get it to go up.

Been trying to see how 2.5 psi does. 1.5 is about as high as I can get it. in the pix below, the engine is idling.

Any tips on what is going on? Is this a crappy regulator? What might be better? Does it take a long time for a SCREW turn to register on the gauge?

I think I will remove it and see what the electric pump puts out on it's own.

I can then maybe take it apart and see if there is something in it....

Other than that, I guess I need to try a better model.

[porschetub]

new question here tho.....

anyone use a QFT pressure regulator?

This one is giving me trouble. At first I could not get it to go down...... Now I can't get it to go up.

Been trying to see how 2.5 psi does. 1.5 is about as high as I can get it. in the pix below, the engine is idling.

Any tips on what is going on? Is this a crappy regulator? What might be better? Does it take a long time for a SCREW turn to register on the gauge?

I think I will remove it and see what the electric pump puts out on it's own.

I can then maybe take it apart and see if there is something in it....

Other than that, I guess I need to try a better model.

Looks like a knock off of the Holley LP one ?,with the adjuster set like that you will be getting full pump pressure , however it maybe ported in a differant way ,unlikely but what happens when you screw it out ? if no result just replacing it would be better ,the Holley 12-804 will suit your needs and a well proven unit , just make sure your pump pressure isn't exceeding the range of the regulator by too much ( 1-4psi ) , by all means remove the regulator as it will give you a better picture and also indicate your gauge is ok .
Good luck ,cheers.
Edit ...what is your pump pressure ?

[Superhawk996]

Viton did the trick.

(IMG:style_emoticons/default/smilie_pokal.gif)

Curious if these were Webers or are they EMPI knockoff?

I remember way back when I got my first IDFs for my original1.7L back in late 80s, they came with solid brass float needles. But subsequent rebuild kits always came with rubber tipped.

Somehow I thought Weber had probably migrated to rubber tips as original parts. Wondering if this is the case?

@malcolm2

[stownsen914]

Two questions:
1. What fuel pump are you using? It's possible it's output pressure is very low, and an inline regulator plumbed upstream from the carbs can only lower pressure from what the pump puts out, not raise it.
2. You don't have a return line plumbed, right?

[malcolm2]

Viton did the trick.

(IMG:style_emoticons/default/smilie_pokal.gif)

Curious if these were Webers or are they EMPI knockoff?

I remember way back when I got my first IDFs for my original1.7L back in late 80s, they came with solid brass float needles. But subsequent rebuild kits always came with rubber tipped.

Somehow I thought Weber had probably migrated to rubber tips as original parts. Wondering if this is the case?

@malcolm2

They are Webers.

[malcolm2]

Two questions:
1. What fuel pump are you using? It's possible it's output pressure is very low, and an inline regulator plumbed upstream from the carbs can only lower pressure from what the pump puts out, not raise it.
2. You don't have a return line plumbed, right?

Rotary Electric Fuel Pump, 3.25 psi

https://vwparts.aircooled.net/Rotary-Electr...ed-p/rotary.htm

no return line. Tank to pump. Pump to regulator, one side thru the gauge, last stop is to the webers.

[malcolm2]

Just sitting all week at the last regulator setting.... no other changes

I started it up last nite and the gauge hit the advertised PSI for the pump... 3.0+. Driver side carb was popping. I hope from too much FP.

I gave the regulator screw 2 full turns. Will re-start and see where the gauge goes.

UPDATE: Tinkered here and there with this regulator screw. It finally got to a point where I could see the needle move as I turned the screw.

So at about the 1/2 way point on the screw is where the action starts. I was able to set the PSI at about 2.5.

Started nicely, ran very smoothly, saw no leaks during the Engine OFF tinkering. I think I got it. Never ends tho.

[malcolm2]

This issue is never ending......

I took the regulator out of the fuel line. Left the gauge.

I started the engine and saw 2.5 psi. So I took it for a drive around the block.

Seemed to run fine. I did get one LEAN POP during that drive. I stopped a few times and checked the gauge. PSI was not staying at 2.5. By the time I got home it was less than 1.0 psi, again, with no regulator. I parked it and returned in about 10 minutes.

I could hear the fuel filling the carbs. Took the air cleaners off and YEP. Fuel running into all 4 carb ports.

Even with Viton tipped float valves, I am getting a siphoning action with the engine off. Tank is about half full. I pulled the hose from the Tee that is replacing the regulator and raised it above the tank and the flow stopped.

Sorry, but you may remember, this is a 72 bus with a 2.0 TIV. You guys seem to provide the best troubleshooting, so I come back here.

I think I have a Carter electric spare pump, I am gonna install that tonight. Should the pump allow fuel to pass thru it with the engine OFF?

[Superhawk996]

Post picture of where you have fuel pump mounted relative to the fuel tank.

If you are getting a siphoning effect, the pump needs to be mounted higher. Especially since the tank is located higher than the carb bowls and would be able to supply fuel pressure via gravity. Ideally pump would be at top of tank level to break any siphon effect.

@malcolm2

Full transparency - I don’t know (IMG:style_emoticons/default/stromberg.gif) about busses. Just giving you the theoretical answer of what needs to be done to break a siphon effect.

[malcolm2]

Had a similar thought. Run the hose, at least some of it, higher than the tank. Would be easy to try.

If I remember correctly, the pump will push the fuel. It does not do well pulling it from the tank. My old cabriolet MK1 had a pump in the tank and one under the tank.

Regardless, the damn viton tipped float valve should hold back fuel, right? Very low pressure if the pump is off, I would think.

They used L-jet FI in 73. Guess i need to study up on where those were and where the hose ran.

[Superhawk996]

Regardless, the damn viton tipped float valve should hold back fuel, right? Very low pressure if the pump is off, I would think.

I don’t think I’d agree.

When the gas tank is higher than a carb and can be gravity fed, it usually has a fuel shutoff valve. This is true with my 1948 Case tractor, lawnmowers, generators, etc.

However in all my experiences with hydraulics, it is always assumed an orifice will bleed down over time. This is true of hydraulics spool valves, solenoid valves,etc. Though they may leak down very slowly, they all leak down to some degree. This is also true of solenoid valves in ABS/ESC modules - the solenoid valves all have a degree of leakage over time if you attempt to use them as a long term line lock.

You could try adjusting float level to provide more sealing force but that may cause other issues (low fuel level in bowl) when running.

Picture I found of a bus and fuel pump

[malcolm2]

i have some feelers out to see what the OEM L-JET FI (1974 and up) fuel line diagram or pictures look like.

I might look into something similar to your picture. Also need to study up on if the electric pump is ok to SUCK fuel at a high point, similar to your pic.

[Superhawk996]

i have some feelers out to see what the OEM L-JET FI (1974 and up) fuel line diagram or pictures look like.

I might look into something similar to your picture. Also need to study up on if the electric pump is ok to SUCK fuel at a high point, similar to your pic.

Agree, it would be better to leave pump at low or mid point and have part of hose (pressure side) higher than tank.

Here’s another example with a Facet pump more at mid tank level


I’m not a fan of facet pumps due to their noise but they do have pumps available with an anti-siphon valve

https://www.pegasusautoracing.com/group.asp...ID=FACETSHUTOFF

[flipb]

i have some feelers out to see what the OEM L-JET FI (1974 and up) fuel line diagram or pictures look like.

I might look into something similar to your picture. Also need to study up on if the electric pump is ok to SUCK fuel at a high point, similar to your pic.

Agree, it would be better to leave pump at low or mid point and have part of hose (pressure side) higher than tank.

Here’s another example with a Facet pump more at mid tank level


I’m not a fan of facet pumps due to their noise but they do have pumps available with an anti-siphon valve

https://www.pegasusautoracing.com/group.asp...ID=FACETSHUTOFF

Ooooh, this is fascinating. I think my 2056 with EMPI IDF carbs has a similar problem. Facet pump relocated to the steering rack (from before I owned it). Strong gassy smell after driving and I've had issues with excess fuel getting into the cylinders, especially #3. Fouled a spark plug a while back. I wonder if the anti-siphon fuel pump would help.

[nditiz1]

Carbs will always have a gas smell when left to sit in a garage as they are an open system. Some run the bowls empty in the driveway and coast into the garage after it stalls.

The tank is about even with the carb inlet on your 914 so I'm not sure gravity pressure is the problem. The only time I have seen carbs drip extra fuel is when a problem with the float and needle is present. "Side load" is the term that is used when the float does not evenly press on the needle allowing fuel to continue to fill the bowl.

Maybe this was discussed, but where exactly is the drip coming from, aux venturi OR the accelerator tube? If auxiliary venturi then float overfill, if accelerator then the check valve has failed.

[malcolm2]

Carbs will always have a gas smell when left to sit in a garage as they are an open system. Some run the bowls empty in the driveway and coast into the garage after it stalls.

The tank is about even with the carb inlet on your 914 so I'm not sure gravity pressure is the problem. The only time I have seen carbs drip extra fuel is when a problem with the float and needle is present. "Side load" is the term that is used when the float does not evenly press on the needle allowing fuel to continue to fill the bowl.

Maybe this was discussed, but where exactly is the drip coming from, aux venturi OR the accelerator tube? If auxiliary venturi then float overfill, if accelerator then the check valve has failed.

I assume the float is over filling. Fuel spreads out on the gasket between the top plate and the main housing. Finding it's lowest point the fuel flows into the barrels. It also flows to the outside of the housing and flows down the carb.... makes it's way to the garage floor.

This time most of the fuel was going in the barrels. I disconnected the hose and raised it up... flow stopped. After the bowls evened out the flow stopped and I got some paper towels and stuck them in the barrels to absorb the fuel that was pooling on the throttle plate.

[malcolm2]

hose path today. yellow line comes out of the btm of the tank to the pump mounted on the side of the frame. Red line goes thru the firewall to the red box (a regulator and gauge). this picture has the removable firewall removed, which is where my regulator is mounted. Purple to the carbs.




Might try this.... run the white line up into the rear quarter panel cavity and back down to the regulator... which is now a BRASS TEE and the gauge.

[Superhawk996]

That’s a lot of hose (white path)

Could do this (green) - just get to top of tank and then back down to regulator ? Could do a sort of u-turn drip loop if line has to enter from bottom of regulator?



Another option; can you lower the regulator to get the distribution lines closer to height of carbs to reduce fuel in lines that can be gravity fed?