Weber Won't Idle

Hi guys,
Thought I'd try upgrading to the weber 32/36 carb.All installed and fits beautifully, but can't for the life of me get the thing to idle. This is on my 250 which was running fine with the monojet on it before. Carb was purchased used on ebay, rebuilt it with all new gaskets etc. Linkage is working properly, all jets and passage ways have been cleaned and blown out with compressed air. Float has been checked for leaks and set at proper levels. Fuel is flowing and I am getting proper fuel pressure. Choke has been converted to manual. I have also checked for vacuum leaks with carb spray and did not find any.

Idle speed and mixture have been set to weber initial settings. The van fires up with the choke on and will idle with the fast idle engaged…which is basically the same as giving it more gas and taking it off the idle circuit, correct? The second I try to turn the choke off, it dies.

It came with a 45 idle jet installed, so I thought maybe by upping the idle jet it would solve my problem. I got a jet kit designed for 6 cylinders, so I've got a range of jets to choose from. I've tried everything from a 60 to 90 primary idle jet, and no change.

I feel like I have checked everything multiple times and have ruled out every problem I've read about.

Does anyone have any ideas what the problem could be?? Could my used carb just be defective??

with choke on =u r cutting off air!
pulling more fuel =usually thru booster venturis. yet id guess  these possibilitys=??= idle circuit stipped up? Bad gasket covering an idle area up??  worng base gasket??Float lever??low!!  with choke closed it is pulling fuel =NOT!! thru the idle circuit!! Disassemble & look in all areas of idle circuit. Was carb new?? used?? sat long time??

Look into the gaskets used?? new kit = V/S the old gaskets =holes same & all appear to be correct??

Thanks so far. I actually just picked up the chem dip gallon to soak the carb in. It seems as though it he problem is narrowed down to the idle circuit since it runs otherwise. There's a chance there's something clogged down in there somewhere I can't get with just carb spray. I'm also going to take some old guitar strings and poke through some of the tiny passages just in case.

Im pretty sure I've got the correct base gasket but I've ordered some extra gaskets just in case. I'm also thinking about wet sanding the surface of the adapter plate I got on a flat surface. It's got some casting imperfections on the surface that can't be helping my cause.

To be continued...

watch the soaking !! dont put any parts that are =NOT!! METAL in that !!
eats them up steel & alu all ok. Be sure to blow out every hole & area with compressed air & after that use carb spray to verify all is open too,

Well good news, I got it to idle! Soaked the carb and all parts for a few hours, cleaned out with carb spray, then meticulously blew out all openings with compressed air.

Now that it idles I have to try to tune it. I can't seem to get the idle mixture screw to have any affect even after changing the idle jet. I have a 45 that came with the carb, then I have 75 through 90 in 5 size increments that I got with the jet kit. Idle speed screw is set to about 1.5-2 turns in.

Could it be the adjuster needle itself? It looked ok to me when I had it apart.

Scotty, I don't know anything about a Weber but I had a similar problem with a Monojet one year when Donivan was here. Turned out to be one of the gaskets flipped and blocking a passage.

if it doesnt idle adjust?? u still have something wrong!!
when i do carbs -i let them soak at least over night!! experience - i know! recheck all gaskets that came with it origionally again too. I will also add = as there are diff brands of spray carb cleaners!!= use only a name brand & usually the most costly one is the best too!! Chemicals inside differ fron 1 to another!

I still need to re-check for vacuum leaks since I reinstalled the carb. I'm also thinking maybe I have the speed screw too far in, taking it out of the idle circuit, rendering the mixture screw useless. The factory specs say no more than 1.5 turns in...I think I'm at 2 right now.

Failing that, I will try soaking again, overnight this time. All in all It's a lot better than where it was, so at least I know I'm headed in the right direction now.

Thanks guys!

Things are getting better. I found my problem was that the spring on the mixture screw was making it so tight, I couldn't screw it in far enough with my fingers to the right spot. I thought it was bottoming out before it actually was, to get the initial setting. Took the spring off temporarily to get my setting.

Backed speed screw out to about 1.25 turns and then adjusted mixture screw to best idle which was right at about 2 turns out with an 85 idle jet.

Took her for a little test drive down the street. Seems pretty smooth once I'm going, but I am experiencing some hesitation off idle unless I really give it gas gradually. Could this still be idle circuit problems (need bigger idle jet for smoother transition off idle)? Accelerator pump issues (it is visually working)?

On another note, should I be running a fuel pressure regulator? I got a cheapo inline one to test, but even set at full 5.5 psi I was only getting a reading of around 2.5psi. Took it off and now I get 3 psi at idle and moves up to around 5 with higher rpms.