Carbs

[sarran1955]

Hi thanks for advice. I think the reading was just above 0.10. I can't remember all the other readings on the computer. Just the one at the top left of the analyser. My cousin altered a tapered screw which I think he said was supposed to be only about 2 and a half turns out but this was way more than that. He said the further out it went the more fuel it lets in and with this wound right out it didn't alter the reading at all. Could someone take a photo of the small vacuum pipes that come off the dizzy and two to air box. I have one that isn't connected and I can't for the life of me work out where it's supposed to go.i will check all your suggestions. My mate said there is something that wears inside the carb which allows more air in but I can't remember what this was.

Was this done on a garage or Mot type of analyser..

If so, where is the print out..

The test must be done properly..

Before you start twiddling the mixture screws and throttle stops..

This will show you where all the bits are, and how to set up the carbs..

https://www.youtube.com/watch?v=najLc9GlLJ0" onclick="window.open(this.href);return false;

I use 'Hawk' engine analysis equipment..

mixture analysers (13.4 parts air to 1 part petrol) can be bought from a well known auction site

Sort all those air leaks first, if need be change any tired looking hoses..

Aircooled bliss..

Cordialement,

[Pummer67]

Hi Mark

It sounds like they need resetting from scratch, and any other issues sorted - as I say, mine was 'orrible when I bought it, and now it's pretty good.

I wouldn't necessarily assume evaporation for the non-starting when hot - I think that it's making assumptions that often leads down blind alleys. If the idle mixture screw isn't making any difference, then there's probably a reason for that, and it's finding what it is, but getting a baseline (i.e. everything set as it should be, and the ignition setup correct and timed up properly) is important. There are plenty of places for air leaks on these engines, and one will definitely ruin the party!

It is, of course, possible that the carbs are worn out (and throttle spindle wear leading to an air leak is certainly a possibility), but before spending £££ (and having some downsides) I think it's worth a bash, particularly as there's no significant cost of getting everything set up properly, other than time.

This page is worth a read: http://itinerant-air-cooled.com/viewtopic.php?t=7767" onclick="window.open(this.href);return false;

On the vacuum pipes front, there is one off the vacuum RETARD which goes to the left-hand carb, IIRC - it should get vacuum only at idle, and it retards the ignition to give it later timing and much lower emissions. The other dizzy connection goes to two places (via a T-piece) - to the vacuum port on the airbox, and also to the link pipe at the back of the engine (towards the front of the van, if you know what I mean!). The second connection on the airbox connects to the flap on the inlet which selects hot or cold air.

Have a look here:

http://s106.photobucket.com/user/phade1 ... n.jpg.html" onclick="window.open(this.href);return false;

1 - connection at dizzy for advance
2 - t piece, connected to dizzy, airbox temp sensor and link pipe
3 - connection to LH carb
4 - connection to selector flap.

On mine, where the carbs were set up wrong (screws all fiddled with), the dizzy wasn't getting a vacuum signal at idle, and it turned out basically every setting had been messed with, so I took them off, did some research, cleaned them up and reset everything to factory. Took me about 2 hours, start to finish, and it was a world apart. The problem is (I think) that most mechanics now don't have to do stuff like this, so they just go "ah, Solex *$^%, put a Weber on it, it's knackered" and that's that.

Anyway, enjoy Wareham, hope it all works out. I can take a look at some point if you want? Problem is I'm not around until end of next week...

Darren

I might have to take u up on that offer if I struggle. I think I need to make sure those no air leaks first before spending out on new carbs or anything. My vacum tubes are not all connected. So should there be two connected to the distributor?

[Pummer67]

Hi thanks for advice. I think the reading was just above 0.10. I can't remember all the other readings on the computer. Just the one at the top left of the analyser. My cousin altered a tapered screw which I think he said was supposed to be only about 2 and a half turns out but this was way more than that. He said the further out it went the more fuel it lets in and with this wound right out it didn't alter the reading at all. Could someone take a photo of the small vacuum pipes that come off the dizzy and two to air box. I have one that isn't connected and I can't for the life of me work out where it's supposed to go.i will check all your suggestions. My mate said there is something that wears inside the carb which allows more air in but I can't remember what this was.

Was this done on a garage or Mot type of analyser..

If so, where is the print out..

The test must be done properly..

Before you start twiddling the mixture screws and throttle stops..

This will show you where all the bits are, and how to set up the carbs..

https://www.youtube.com/watch?v=najLc9GlLJ0" onclick="window.open(this.href);return false;

I use 'Hawk' engine analysis equipment..

mixture analysers (13.4 parts air to 1 part petrol) can be bought from a well known auction site

Sort all those air leaks first, if need be change any tired looking hoses..

Aircooled bliss..

Cordialement,

Brilliant. Thanks for all the videos. Yes it was done at a garage after hours on a mot type analyser. We didn't print it out. I think I need to have a good look through all the information your both giving me. Hopefully I find an air leak and that is the cause of my problem.

[ajsimmo]

There's some poor advice and incorrect info been offered in this thread, such as retard signal comes from left carb and other pipe goes to tpiece etc. Also the video shows a single vac dizzy with the retard (idle) signal port blanked. So ignore most of that.
If you have a dual vac dizzy (as you should) then the retard hose goes from port on idle circuit (behind air box) to t-piece then to retard side of dizzy can (inner one nearest dizzy body). Other one from T goes to airbox temp sensor and from there to air intake flap.
Advance hose goes between dizzy can outer and left hand carb (ported spigot - blocked at idle).
But none of that explains your original problem, which I suspect is the idle cut-off solenoid not opening, so the fuel screw back left will do nothing. With the L shaped hose pulled off the "third carb" inlet (back of left carb) you should hear the inlet sucking air at idle. If not its the solenoid plunger still closed, either lack of voltage to it, bad earth (eg someone taped the threads), faulty unit, or mechanically jammed closed.

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[Pummer67]

There's some poor advice and incorrect info been offered in this thread, such as retard signal comes from left carb and other pipe goes to tpiece etc. Also the video shows a single vac dizzy with the retard (idle) signal port blanked. So ignore most of that.
If you have a dual vac dizzy (as you should) then the retard hose goes from port on idle circuit (behind air box) to t-piece then to retard side of dizzy can (inner one nearest dizzy body). Other one from T goes to airbox temp sensor and from there to air intake flap.
Advance hose goes between dizzy can outer and left hand carb (ported spigot - blocked at idle).
But none of that explains your original problem, which I suspect is the idle cut-off solenoid not opening, so the fuel screw back left will do nothing. With the L shaped hose pulled off the "third carb" inlet (back of left carb) you should hear the inlet sucking air at idle. If not its the solenoid plunger still closed, either lack of voltage to it, bad earth (eg someone taped the threads), faulty unit, or mechanically jammed closed.

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My dizzy only has one vacum take off. I have a spare short length which is connected to air box and would reach the dizzy but no connection for it on the dizzy just one. Which dizzy should I have on this van?

[ajsimmo]

Should be this one.

[Pummer67]

This is mine. Only has 1 vac take off I think. I'm guna go have another look now though.

[Pummer67]

[Pummer67]

I definitely only have the one take off of the dizzy. And currently have that connected to the left hand carb. Could this be the whole cause of it all. The t piece one is connected to air box and round the back on the cross pipe and across to right hand side of engine bay. But is most definitely not connected to the distributor.

[ajsimmo]

Well that is definitely the wrong dizzy, so timing cannot be set the usual way (to 5° atdc with vac pipes connected, Idle stabiliser bypassed). It should be set with vac disconnected to 7° btdc (as retard would have been ~12°). Then check total advance at >3500 revs doesn't exceed 32° without vac and 42° with.
Also is that loose vac pipe blanked off? It mustn't be left open.
Have you had chance to check the idle circuit?

[Pummer67]

No it's not blanked off. And I haven't checked the idle unit. I noticed it was bypassed but have never actually tried plugging it back in. What dizzy should I have on this engine then? Maybe I need to replace that first and get the timing set correct. then try plugging unit back in.

[ajsimmo]

No leave the idle stabiliser bypassed for now, no need to think about that. I was referring to the idle air circuit - the third carb at rear left of engine with a rubber hose that connects it to the airbox. Have you checked that is actually sucking/hissing at idle?
The open vac pipe is bad news and must be blocked off. I've just reread through your posts and you repeatedly say that you must try to find any air leak. Err....that's an air leak!
Ok, now we've got that out the way you can probably ignore your mate...

My mate said there is something that wears inside the carb which allows more air in but I can't remember what this was.

(Tbh I am starting to wonder if this thread is a wind up...)
But no, I'm gonna persevere!
Next, I've previously posted a pic of the correct dizzy so you know what it looks like. It's not available new so best bet is a wanted ad on this forum (no, not right here, in the Wanted section!) I wonder if anyone else could step in and help from here. Looks like a tag team job.


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[ajsimmo]

It will probably run ok with the dizzy you have but the timing must be set as I've described. Has this been checked?

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[Pummer67]

Thanks for getting back to me. No I haven't checked if it's sucking. That's a job for tommorow. I didn't actually realise the importance of the vacum lines. Across the back there is also a section of hose pipe I spotted earlier. I will post a pic. So I need to fix that aswel. It fires up lovely from cold and with oil temp at about 110 it still fires. But anything around 120 it struggles. And I can drive the van for about an hour before temp is getting to high. I'm learning a lot about these engines quite quickly now. So if I blank off the spare pipe that should make a bit of difference? Can I not join it with the other vac pipe with another t piece as a temp solution or better to cap off?

[Pummer67]

Thanks for your help.