Weber 40 IDF is dripping Options

[malcolm2]

I like your idea. found a few decent pictures of the tank firewall and the tank. Notice the height of the red hose.... and then the height of the tank below. that would never siphon.

[nditiz1]

My feeling here is it's getting kind of crazy and off track.

If this were my bus I'm going back to basics - float level. Also if I purchased a rotary pump that is only producing 2.5 psi then I'm not running a regulator. I'll maybe run a fuel pressure gauge inline just for sanity, but have had similar setups and just ran pump to carbs.

If you really want to test a theory, put gas in a jug attach to a gauge cap the end and raise the jug. It will tell you how much pressure you have. My guess is less than 1 psi. You can also test your needle valve by hooking the jug up to your carb top. Rest the top on the bench so the float is closed all the way. It shouldn't leak. When you set the float level did you get it to 10mm with the gasket in place and the ball not depressed? This is very important.

[malcolm2]

AC.net is out of business, but bought the new idf 40s before they shut down. paid for the cleaning and set up per his recommendation.... 12mm on float level. not sure why it is different than the book, but it is. I re-checked the 12mm when I installed the viton needle valve.

Yes, I have lots of tests to try on this. I did remove the regulator and left the gauge. Really did not see any change to the gauge readings. I start the bus.... I see 2.5 psi, i take a drive. I stop and check the gauge, it is down to 1 or 1.5 psi.

So there are a couple things going on...... 1. the random siphon activity and 2. the low driving pressure.

This whole thing started with the siphon activity. I will re-route the hoses 1st. easy to try.

Then I will change the pump and see if my pressure holds. Might try a Facet pump as recommended above.

All test suggestions are welcome, as thing proceed, I will certainly try anything.

I might be one of the only people to remove carbs and go to L-Jet. (IMG:style_emoticons/default/headbang.gif)

[Superhawk996]

Just a side note on gauge vs pressure.

I wouldn’t trust that gauge as being highly accurate. It appears to be max at about 10 psi and you’re trying to measure down at 1- 2 psi. You can’t expect high accuracy when your nominal pressure and variances are only 10% of gauge and the gauge itself may only have an accuracy of plus or minus 2-5% at standard temperature (73.4 F) and atmospheric pressure (29.9 in Hg).

It may be reading 1 psi hot but it would be hard to tell if that pressure reduction is coming from the pump or the gauge getting hot in the engine compartment.

[nditiz1]

I do trust ACN as most of my carb knowledge came from John over several emails when I was just starting out learning them. 12mm is fine and if anything would shut the flow sooner, so not as filled.

Was the regulator always used with your setup?

[Superhawk996]

Random thought:

Is your tank vented properly? Pressure build up in tank so close to heat source could pressurize tank and fuel supply leading to the flooding of carbs / siphon behavior.

[malcolm2]

Random thought:

Is your tank vented properly? Pressure build up in tank so close to heat source could pressurize tank and fuel supply leading to the flooding of carbs / siphon behavior.

Tank is vented. Picture is not mine, but in the picture of the tank above you can see the yellow hoses they go from the top rear corners of the tank, into the engine compartment and up into the D-Pillars then back down into the charcoal can. There is a "bulb" in each line going up into the pillar, i assume it can assist in pressure and siphoning.

[malcolm2]

I do trust ACN as most of my carb knowledge came from John over several emails when I was just starting out learning them. 12mm is fine and if anything would shut the flow sooner, so not as filled.

Was the regulator always used with your setup?

Anyone know where John is now? Hated to lose Cap'n Krusty on here. John was a great resource on the Samba. Kinda Krusty too (IMG:style_emoticons/default/smile.gif)


Was not there when I ran the engine on the floor of my garage, but I added it as I installed. The low pressure pump is probably fine by itself. Don't see a benefit with it, as I have run with and without.

I guess it is a help if you have a higher PSI pump and need lower psi to run. I guess I listened to some of the inter-web garage hands that maybe only give their personal info and don't always have all the reasons why. Taught me something tho.

[Nogoodwithusernames]

You sure those venting lines are clear and not plugged up? It's pretty common on the T3 (not the van T3, the Squareback, Notchback, Fastback T3) for the fuel tank vent lines to get plugged up with rust and junk.

Also on Pg.1 you note that you have those two vent lines connected together which will effectively NOT vent the tank FYI. It's just a closed loop at that point.

I am not familiar with the bus evap system, but on the T3 the vent lines went back to the engine after the charcoal canister and it would pull those fumes into the intake system. I used a kit Jim Adney makes to bypass all that since it is more than likely plugged up anyways, so my tank is open to atmosphere now. The canister on the T3 also tends to collect crap from the road and cause rust under the fender so that was extra motivation.