No Idle on 1600 Aircooled ct engine.

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totallyconfused
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No Idle on 1600 Aircooled ct engine.

Post by totallyconfused »

Hi, having a problem with my van. The engine starts and runs fine when the aitomatic choke is engaged. Once the choke warms up and goes to lower rev idle the van splutters and cuts out.

If I give it a little throttle it will run. Soon as you drop the revs it cuts out.

I have stripped the carb and cleaned all the jets. Wierdly, if I turn the idle adjuster screw it does nothing?!?. Should it be turn in to speed up, or out?

Cant see any obvious air leaks.

Disconected the idle stabiliser unit....this didn't seem to do anything.

Any ideas? Many thanks.

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1981 - Aircooled 1600 Fire Bus.

Not a camper, Not a pop top, Not Nato Green, its a German Firebus!

Becky's Dad
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Re: No Idle on 1600 Aircooled ct engine.

Post by Becky's Dad »

What carb(s) ?

If its the same as a 2.0 CU I'd tap the idle solenoid at the back of the LH carb to see if its sticking - mine used to.
Also if you've suffered any backfires I'd also check the welch plug at the rear of the carb as this can cause a big air leak if its missing and lead to rough running.
1982 Aircooled 2.0 Petrol - Autohomes Pop-Top

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totallyconfused
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Re: No Idle on 1600 Aircooled ct engine.

Post by totallyconfused »

Hi, its a solex pict 34 - 4 carb. Sorry, should of said that.

Really confused as to why turning the idle control screw does nothing. Could this mean there is an air leak thats over riding the screw?!?

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1981 - Aircooled 1600 Fire Bus.

Not a camper, Not a pop top, Not Nato Green, its a German Firebus!

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bigherb
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Re: No Idle on 1600 Aircooled ct engine.

Post by bigherb »

First, check the idle control solenoid on the side of the carburettor is working, with the ignition switched on, pull off the wire and reconnect the solenoid should make an audible click.
Image

Then check the idle jet is not blocked.
Image
1982 Camper 1970 1500 Beetle Various Skoda's, Ariel Arrow

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totallyconfused
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Re: No Idle on 1600 Aircooled ct engine.

Post by totallyconfused »

Will do. Many thanks for the help. [SMILING FACE WITH SMILING EYES]

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1981 - Aircooled 1600 Fire Bus.

Not a camper, Not a pop top, Not Nato Green, its a German Firebus!

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sarran1955
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Re: No Idle on 1600 Aircooled ct engine.

Post by sarran1955 »

Hello,

A video to help:

https://www.youtube.com/watch?v=Dctz_4dKoJo" onclick="window.open(this.href);return false;

As has been said above, make sure there are no inlet air leaks

If the idle air screw, (the big one) is making no difference, it may well be that its rubber sealing ring is broken,perished, or gone AWOL.

Hope this helps,

Cordialement,

:ok
Image

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totallyconfused
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Re: No Idle on 1600 Aircooled ct engine.

Post by totallyconfused »

How do, thanks a lot for the images...really helpful.

Cjecked the solenoid...thats fine. Nice loid click.

The idle jet should be fine, as have stripped down carb and cleaned jets. The jet is clear. So if I spray carb cleaner in hole where jet goes where should it squirt out??

Just wanna check the passage isn't blocked. Should it come out the grey tube in the centre of carb hole?

Thanks.


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1981 - Aircooled 1600 Fire Bus.

Not a camper, Not a pop top, Not Nato Green, its a German Firebus!

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totallyconfused
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Re: No Idle on 1600 Aircooled ct engine.

Post by totallyconfused »

Hello Sarran,

I used your video to strip down the carb. It was great.

The screws have rubber washers on, so they should be working.

I used a new gasket on the inlet when I put the carb back on. Could tighten that down more?

Do you mean a leak fron the rubber boot on the inlet mwnifold?

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1981 - Aircooled 1600 Fire Bus.

Not a camper, Not a pop top, Not Nato Green, its a German Firebus!

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totallyconfused
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Re: No Idle on 1600 Aircooled ct engine.

Post by totallyconfused »

Hello again.

I ended up swapping over the original carb for a spare one.

I have now got the van running at Idle. The tick over seems a little fast. (I am going by ear only, I dont have a tachometer).

I have tried turning the idle adjuster screw and again it doesn't seem to do anything. [ASTONISHED FACE]. I have driven the van and no more stalling. I have but new rubbers on both the co2 screw and the idle screw.

Not sure what to do as it now seems it is not possible to alter the carb settings?!?!.

Any ideas, thoughts will be greatly appreciated.


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1981 - Aircooled 1600 Fire Bus.

Not a camper, Not a pop top, Not Nato Green, its a German Firebus!

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sarran1955
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Re: No Idle on 1600 Aircooled ct engine.

Post by sarran1955 »

Hello,

If the idle screw makes no difference, then you should look at 2 things..

1 make sure that the bottom butterfly is set with the correct 0.8 to 1.00 mm gap at operating temp.

2 make sure that the throttle cable is correctly positioned and tensioned..not keeping the butterfly a bit open..

Hope this helps,

Cordialement,

:ok
Image

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totallyconfused
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Re: No Idle on 1600 Aircooled ct engine.

Post by totallyconfused »

Thanks a lot,

I am sure you are spot on. I looked at the carb with it off the vehicle and realised that the bottom butterfly was completely shut when the choke cam was not engaged. It was open when the choke cam was engaged.

That explains the engine cutting out as soon as the choke warmed up.

Apologies for wating your time!!!!

I am going to set it as per your video.

I also realised that I was meant to disconect and block all the vacuum pipes before setting the revs. Guessing this is why the screw was doing nothing. Sound about right?

I guess I am certainly living up to my sign on....DOH.

Many thanks.


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1981 - Aircooled 1600 Fire Bus.

Not a camper, Not a pop top, Not Nato Green, its a German Firebus!

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sarran1955
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Re: No Idle on 1600 Aircooled ct engine.

Post by sarran1955 »

Hello,

Not a problem, we all have to learn, and one day all this stuff will help you to get out of trouble with a breakdown..

...probably someone elses.. :roll:

totallyconfused wrote:
I also realised that I was meant to disconect and block all the vacuum pipes before setting the revs. Guessing this is why the screw was doing nothing. Sound about right?


I assume you have standard ignition set up..

In the video all the vacuum tubes are blocked off just for the idle and CO set up.

When you reconnect all the system of vacuum feed to the aircleaner and front of carb there should be no difference in engine speed, if there is then make sure that the
vacuum system, especially the sensor valve in the air cleaner, is working.

Air-Cooled Bliss.. 8)
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totallyconfused
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Re: No Idle on 1600 Aircooled ct engine.

Post by totallyconfused »

Hello Sarran,

I have a bosch distributor with electronic control. It has a vacuum bit on side though.

Having a lot of trouble finding a carb rebuild kit that has the right accelerator and choke diaphragm. The kits I have got seem to only fit upto a pict 34 - 3 carb, not a 34-4 carb. The diaphram bits are trianguler, not square, or square but too small. Any ideas where I can get the right kit from?





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1981 - Aircooled 1600 Fire Bus.

Not a camper, Not a pop top, Not Nato Green, its a German Firebus!

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sarran1955
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Re: No Idle on 1600 Aircooled ct engine.

Post by sarran1955 »

Hello,

Like this:
Image

From here:

https://www.serial-kombi.com/en-GB" onclick="window.open(this.href);return false;

Reference 070198537

I have never liked the DVDA electromechanical timing..
and so use either a points and condenser distributor, or a Powerspark,

Like this:

https://www.youtube.com/watch?v=WJPyPuJZkHU" onclick="window.open(this.href);return false;

Runs sweet.. 8)

Hope this helps.. :)

Cordialement,

:ok
Image

paperhouselad
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Re: No Idle on 1600 Aircooled ct engine.

Post by paperhouselad »

Hi, i can vouch for a powerspark set up, sarran guided me through converting from original set up to powerspark, big difference for the better. Although on 2 lt cu engine.

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