weber question

[CzEcHy]

Ehh, weekly update..

Redid all Carb gaskets with new rtv, replaced brake booster hose. No other possible vaccum leaks besides intake gasket. Still bogs and dips.

Brand new spark plugs, still bogs and dips.

Repositioned throttle shaft via hit lightly with screw driver handle, still bogs. Removed linkage from carb completly and used finger to flick throttle, still bogs and dips

Unplugged vacuum advance completely, idle raised, still bogs and dips


My idle is virtually smooth as a new car so I rule out vacuum leak. My spark plugs come out after idle a nice tan color (not to rich or lean), so my mixture is spot on basically.


I'm at a loss now, maybe its flooding? Maybe the acceleration jet is to big? The car runs great except that bog, and I wanted this Carb for low end not high end, so that bog has got to go. I must say tho, a 50 to 80 pull takes mere seconds. Passing cars is easy easy, even at freeway speeds. Ill have to get a video sometime.

EDIT 12/30 - that needle idea didn't work either Guy, fuel was just spraying everywhere so can't remove needle. I think my float may be off some, I'm trying to find someone near me with Weber experience to look over things for me but I'm having no luck, guess everyone owns FI vehicles. Tired of standing outside for 1-2 hours a DAY trying to fix this bog.

Also, happy birthday Guy!

[2oodoor]

thanks,
I dont know where you got this needle idea from?
I look at the diagram now and it looks like you have some adjustment there with that, does it have to be screwed all the way in or can you leave it up some?

the kind of hesitation you are describing certainly sounds like an accel pump issue however it could be a transistion issue caused by float level or stopped up hole in the bowl.
You may get away with removing the accel pump diaphragm housing without damaging the pump diaphragm so I would look in there to make sure you dont have garbage in a hole or something. You say you have a good squrit wiht the pump but what is the duration of said squritage.. lol. could still be a bit on the lean side.
Exactly when is the pump lever contacting the pump from when you hit the throttle? is it possible that got bent at some time? you should see a steady stream of gas coming from the pump jet the second you even breath on the throttle, yes and that stream should continue a few seconds as you continue to press the throttle.
Ok , now on the over rich side, even if you got all the squirtage if you happen to be flooding for some reason during this time then you will get the same bog! you would be smelling gas a lot if that was the case, it would be a puddle of gas lying in the manifold just under the carb... waiting to get enough air to move it on into the combustion chamber.
The reminds me of this same issue which I had on a DGS where I goofed and put a DFAS pump jet on it. Guess what, they are backwards so I was not getting a squirt in the primary barrel at all since there was only one opening on the jet going into the wrong barrel.
word to the wise, keep the rtv the hell away from the carb above the mounting flange lol


something else to try for squirts and giggles is to turn both the idle mix screws in a half turn, ignor the idle change and drive it to see if you notice any improvement in bog.. if so then a lean best idle procedure needs the do over.

[TotaledTL]

Why are you using RTV? Don't the directions specify Gasgacinch? I used a spray copper shellac type of gasket coating since I couldn't find Gasgacinch.

Try looking for somebody who works on old VWs as they often used Webers. That's what I resorted to.

[2oodoor]

for those spacers I use permatex hitac , brush in the can type

[CzEcHy]

K..


Number 61 in the chart, the arm thing on the throttle. When connected is opening the butterfly in the barrel closest to the firewall (choke side). Which is causing the small holes in the barrel to be exposed. The enrichening holes I believe. So that barrel is always in the "transition stage" even at idle.

Is this my problem, or normal? The arm is to short so I tried everything to get the butterfly to close fully but as soon as you reconnect that arm it pulls the throttle open and shows an enriching hole but the other barrel is closed during idle completly.

I had the carb off and found this out.


FYI the holes being open indicate the same problem as having the idle speed screw past 1/2 turn Max (mine was completely backedcout when I noticed the number 61 arm thing). according to the booklet and various websites, it causes a rich condition at idle and a stumble off idle to 1800rpm.

I need a longer arm, like mere MM to correct it.

[2oodoor]

OK, if the choke is closed that rod is supposed to hold the throttle slightly open. That is what makes fast idle for warm up until the choke opens up. There also is an adjustment on the carb on the opposite side I think (without having the carb in front of me now) that you can adjust how open the throttle is at fast idle, hence fast idle speed adjustment.

If the choke is opened fully and that rod holds the thottle open still then something is bent or binding or the actural throttle stop screw is holding the throttle open some..

[TotaledTL]

Is the fast idle supposed to remain engaged until the choke heater has been on for a certain period, or is it normal for fast idle to disengage as soon as you blip the throttle?

[2oodoor]

all the ones ive had it disenguages too easy like you describe but the choke is still angled slightly closed to enrich. That said, weber doesnt have much of a step down cut into that cam thing that catches the throttle, usually on other carbs you will see a few knotches that step it down some as the choke opens.
The manual choke weber I had worked out better with that issue because I could gradually taper the choke angle and it worked better for those first few stoplights in the morning lol.

[2oodoor]

Here are some pics of my 38 with the top hat adapter and oem cable linkage tab bolted to the weber linkage tab...

[2oodoor]

never detailed engine compartment so excuse the lackluster but here is the larger air breather I was able to use after the adapter.