Screwed up my timing...

[73citrus]

New exhaust

[73citrus]

I have not driven the bus with the new exhaust installed. So I don’t know if the whistle is still a thing.

[Wildthings]

Have someone else start the engine and keep it running as near idle spped as possible. Now with the air cleaner removed take your splayed fingers and lay them over the inlet to the carb and slowly bring them together. If the idle picks up at first you are likely running lean and if it just wants to die that much easier you are running rich.

You can also rev the engine with one hand and then use the other to block off the air flow and try to stall it out, do this a few times and see what happens. Just open the throttle wide and bring it down to a near stall with your other hand over the air horn.

Does the electric fuel cut off on the carb click as your turn the ignition switch on and off? It should.

[73citrus]

Electric cut off on the carb clicks when the key is turned.

Closing spayed fingers over the air intake makes the motor die right away, no pickup.

[busdaddy]

[73citrus]

When throttle screw and cam are in this position it ran unassisted, as it started stepping down the notches on the cam is when it wanted to cut out.

[Wildthings]

Is your idle jet screwed in all the way? Pull it and inspect it.

There will be an air correction jet for the idle system, if it is clogged the idle would be off the scale rich. Don't have a carb in hand to inspect to know exactly where the jet is. Solitary bees are known for clogging such things.

[73citrus]

Main jet size 130
Air correction jet size 70
Idle jet 55

Just took them out and they all looked clear, but I blew them out with carb cleaner and reassembled...

Any suggestions on the jet sizing?

[73citrus]

Let me know if I need to start a new thread since I’m now talking about my carb...

Changed the jets on the carb with what was in the carb when I first got it...

Main 127.5
Air correction 125
Idle Jet 65

I will say it ran smooth and idled for about a minute until the choke started to open back up, then the motor cut out.

I turned the throttle adjust screw in two more turns against the cam and turned the bypass screw to 3.5 complete turns and the volume 5 complete turns... still dies

Any advice?

[busdaddy]

[73citrus]

Turned it back as you suggested. I’m going to double check vacuum leaks at this point. Have decided to take the intake manifold off and change out the gaskets between the manifold and block

[SGKent]

will it run if the throttle is held open?

Have we confirmed the timing is correct?
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[73citrus]

It will run as long as I give it gas.

I am waiting on a timing scale to come in, but I set it 7.5degrees before tdc

[SGKent]

[73citrus]

Also changed the plugs, now she idles on her own.

Have you guys seen the bypass screw have a vacuum leak? I can here a hiss coming from the engine bay around the carb and the bypass screw is very cold. The base of the carb is also cold with condensation.

Drove around the block and if I barely give it throttle everything is fine but it I give it a lot of throttle engine boggs down.

I probably have a multitude of issues but you guys have got me running and idling so I figure if I let you know what’s going on y’all will keep dishing the helpful comments... it’s been much appreciated!

[busdaddy]

The screws have O rings on them that act as a seal as well as keeping them from self adjusting, screw it all the way in counting the turns, then unscrew it fully and pull it out (you may need tiny needlenose pliers or a pick) and look at the O ring for a split. Or just cap the end of the tube the screw is in with your finger to see if the idle changes.

If there's no aircleaner on it, or a crappy paper or chrome one you'll hear the idle system hissing, that's normal, are you positive the sound is coming from the outside?, what happens to the engine speed if you spray carb cleaner or propane (unlit torch) on the suspect area?

The base of the carb getting dewy or even a little frosty is also normal, the pressure drop and evaporation that happens in there is basically the same principle as what happens in your fridge or A/C machine. VW solved the problem by heating the manifold on single carb applications, you don't have that so you'll have to settle for the best idle and do some jetting and adjustment as well as distributor work to reduce that flat spot when you mash the gas pedal.
Deviating from a stock system has it's downfalls sometimes.
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[73citrus]

I do have the cheap chrome air cleaner so this is probably the hissing source, it certainly seems to be coming from there.

Checked the o ring and all is well, thank you for the condensation/cold carb run down. Spraying around the carb and intake with carb cleaner does not change the engine rpm. With you explanation of the air cleaner I believe at this point I can rule out vacuum leaks.

Now, ruling out vacuum leak I need to figure out the flat spot... I know it’s been brought up before that the 34pict3 isn’t typical on my engine so asking a general jetting question to the masses probably won’t get me anywhere but if you have any jetting size suggestions I will be open to it.

[busdaddy]

The best place to start is with the idle jets, bigger fuel or less air, but maybe play with the acellerator pump linkage first, there's an 8mm bolt head in a curved slot on the RH side of the throttle shaft, one end of the slot has a +, move the bolt head towards that a little and see how it behaves. Careful, it's easy to strip the threads on that bolt, tighten it gently.

That chrome air cleaner doesn't muffle intake noises so maybe that's what you are hearing. The 34PICT3 has a tiny second carburator of sorts built into it for the idle circuit (that's why the throttle has to be fully closed), it makes a sucking/hissing noise when operating, the stock air cleaner muffles the sound.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[Wildthings]

Most 34pict3 carbs were designed to work with dual vacuum distributors, on a 1600 engine if they are used without a working vacuum retard can, they will not idle down correctly and attempts to make them do so will cause an off idle lag. On a 1600 engine the trick is to close off the hole that is drilled in the throttle plate with a pop rivet and then tune the carb normally. I would presume on the two smaller sized Type 4 engines this same trick would work, while on the 2.0L it might not do as well.

If your carb has a hole in the throttle plate, then closing it off might well be a good first step.

[73citrus]

Realize the 34 pict-3 carb is not correct for my 1.7 l type 4 engine.

I want to put the correct setup and move forward, since it’s already setup to put a 32/36 Weber progressive I was leaning on that but I have the money to go with the dual Weber 40 idf so I was strongly considering just pulling the trigger with those. At this point I want to bus to run correctly and am willing to buy what it takes to get it there.

Any advice from you guys with years of experience would be appreciated (including who to buy from, cb performance?)