Hot idling issue

[chris86uk]

Hi everyone.

1600 TP 1977.

Firstly, apologies. I have ran a search and there seems to be quite a few people with similar problems but I'll explain.

I've had my bus two years now and worked on it EVERY day off I've had. Anyway finally got it all finished and I'm hoping to go camping next week.I took it for it's MOT (England) today and it PASSED! So up until that point I was having a great day and the camping trip was on!

I took it for a run (as it's been standing for two years) and all was going well. Took it down the motorway at 50mph and pulled off at the next junction. At the top of the slip road it stalled as the revs fell to idle, and continued to do this all the way home
What makes this worse is that I have a problem down shifting to 2nd, just refuses to select the gear, so combining the stalling problem with this makes the bus practically undriveable.

As I said, I know there are threads about this kind of problem but I was hoping maybe something specific would jump out at you guys and you'd be able to point me in the right direction, I'm working every day now until my planned trip so I haven't got much time to sort this at all.

[EDIT] Just noticed 2 things, firstly the exhaust tail pipes are sooted up quite badly and they weren't this morning (although it is new and only idled in the yard since I fitted it about a year ago) and secondly it won't idle even though it's been sitting for about 2 hours.

Thanks for ANY help/advice

Chris

[busdaddy]

Could be alot of things, extra black pipes isn't good and could point to a rich condition, that would also explain why it worked when cold but not when hot, try screwing the small screw on the left side of the carb in until the revs pick up, if it makes no change or makes it worse go back.

As for the shifting will it go into second OK when the engine is shut off?
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[SGKent]

[aeromech]

[grandpa pete]

there are several video's on u tube for adjusting the carb and/or you could read more at www.speedyjim.net
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[chris86uk]

It isn't old petrol, there was some old stuff in the tank but it ran fine on that, plus I put about 20 litres of fresh stuff in today.

I'll check those wires mentioned above, the choke and adjust the screw that busdaddy mentioned;

Is this the screw?

As for my 2nd gear issue, no, it only seems to do it when I'm driving, it doesn't when the engine is running but I'm stopped. Synchro?

Thanks for all your replies, very very helpful and noob-patient as always!! Sorry for my ignorance, I'm a fast learner though so I'll pick this all up in no time I promise!

[busdaddy]

Do check the electrical connections SG and AM mentioned.
The screw you want is the much smaller one just below the circled one, the circled one controls idle speed, not idle mixture.
If the shifting only does it running and only that gear it's very likely a syncho, try an oil change in the transmission for starters.

That rubber part on the vacuum advance line looks extremely old and dry, I'd change that as well as any others that look similar, could be contributing to the issues. That fuel line doesn't build confidence either, in the 21st century the safest line for a bus is J30R9 hose and lockwire around the casting on the carb to prevent the fitting from pulling out.

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[chris86uk]

Great, I'll have a go on Thursday after work.

Just to be clear...

Red Circle - This is the idle mixture screw
Green Circle - Vacuum Advance, change this and others in similar condition.
Blue Circle - Dodgy fuel line! ARGH!

You think I'd be better with this J30R9 than this;

http://www.justkampers.com/vw-t2-bay-window-parts/...-hose.html

Is 5 or 7mm the correct size? I'm finding both mentioned?

I noticed that the J30R9 doesn't have the fabric braiding on the outside, I assume that doesn't matter?

SO GLAD I POSTED THAT PIC NOW! Thanks again!!

[busdaddy]

Correct on all your coloured circles!

That JK stuff is only rated to R11 which is vent and vapour , it may be OK but I've had too much top notch German as well as other high end fuel line break down and start peeing fuel for no reason aside from fuel additives and in months instead of years too, so far the only line that resists is the R9. There is a guy selling it on EbayUK , you want the 5.6mm stuff, it's smooth on the outside and quite stiff and doesn't appear to have a liner like the Goodyear stuff but after a year it's been holding up for me, I plan on a major tune up in the next few days so if I find any issues with it during close inspection I'll let everyone know.
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[chris86uk]

Superb, thanks so much busdaddy!

I'll try to get hold of the Goodyear stuff I think, it's well worth it isnt it!!

Thanks again

[busdaddy]

It is, bus at least around here it only comes in 1/4" which is slightly too big for the fittings on the bus, you can squeeze it down with clamps but the 5.6mm is tight even before clamping.
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[busdaddy]

[chris86uk]

I could only get hold of the non Goodyear stuff so it'll do for now, fitted it today.

Right..... *holds head in hands*

Still hoping to go away on Thursday in the bus but I just can't get the damn thing running right.

After I'd changed the fuel lines and filter, I moved on to the suggestions everyone made the other day.

I replaced my vacuum advance lines and then moved on to adjusting the idle mixture. I tried adjusting it both ways but to no avail, just splutters and then cuts out.
I read that I should only make tiny adjustments, which I was doing, but it could be miles out for all I know. I'm sure I read somewhere that there was a 'base' setting, a certain number of turns out from fully 'in', does anyone know anything about that? I'm willing to try!

When it's spluttering, if I gently blip the throttle I can coax it into idling ok for ages sometimes but if I give it a rev and then let it fall back to idle, that's when the problems start.

I know this is probably so difficult to advise on when you can't physically see/hear/adjust in person but I really appreciate any pointers.

[chris86uk]

Also,

I think the choke is operating correctly, when I start from cold the pin is on the third step (red arrow) and it gradually moves to the first step (blue arrow), when it gets there though, it starts to splutter.

Which leads me back to the rich running doesn't it? Going round in circles.

[busdaddy]

If that photo was taken when it's fully warmed up it's wrong, it should be on the last long rounded step below the one your blue arrow is on and it shouldn't really touch that area more than very lightly.
Start by losening the 3 screws holding the choke heater (round disc on RH side of carb with wire attached) on and twist it ~1/8 turn clockwise when viewed from the RH side so that cam is just all the way up (retighten screws gently). The plate in the carb throat should be fully vertical when warm and ~3/4+ closed when cold (depends on ambient outside temp, if it's near 0c/32f it should be fully closed). Until that high idle screw is off the stepped plate and the throttle plate is fully closed idle mixture adjustments won't have any effect and it'll run crappy.

Don't lose too much sleep over the hose, keep an eye on it and try to find some better stuff in the meantime, you've got at least 8 months and likely more.
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[chris86uk]

Perfect, thanks!

It's bizarre how good it is to have something pointed out as wrong! I'm pretty sure it was completely hot when it was on 'blue arrow' step.

I'll check it out tonight!

[chris86uk]

Right!

Did what you said with the choke, twisted the round disc on the right hand side so that the choke is totally open, adjusted the high idle screw so it just touches the stepped plate very lightly and on the bottom long rounded step.

I played about with the mixture and the big idle speed screw and got it to run like this;

http://s10.photobucket.com/user/chris_86_uk/media/20130415_001.mp4.html

I actually filmed the video to show you how it cuts out when I rev it and then let it fall to idle, but as you can see, it kept running It is mis-firing though isn't it, hear it when I hold steady revs in the video? (21 to 26 seconds in)

BUT I think I've messed up the choke when I adjusted the round disc. After I filmed the video, I waited about an hour and then started it up again, Terrible idle, will only run if I constantly dab the throttle, and the stepped idle cam was still on the long rounded step.
The choke doesn't feel right now, like there's no tension in it. I did pull the round disc out and heard a spring noise, is that supposed to be connected to the disc, or does the disc just compress it?

At least there's a bit of progress anyway. I also sprayed around the inlet manifold boots with some Easy Start to see if there were any leaks but no change in engine note, so I think they're ok.

[busdaddy]

Sorry, the video does little for me through my crappy laptop speakers

When the engine's absolutely cold and the key hasn't been turned on for 1/2 hour + loosen up the choke and twist it so the plate just barely closes (hold the throttle open while twisting so the screw is off the cam), you may have to do a full turn so the hook on the spring can pick up the lever in there again since it went sproing in there.

A baseline for both the screws on the LH side of the carb is 2.5 turns, careful when bottoming them out as you can damage the seats if you torque the crap out of them, use a little screwdriver so you can't get too medieval with them.

Another trick to try is loosen the idle jet on the RH side of the carb 1/4 turn (it's the hex shaped brass plug ahead and below of the choke, careful retightening it too, be gentle), if there's crap in the carb or it's been overtigtened so bad the seat is squished sometimes the idle improves by loosening it, can't hurt to try.

Have we discussed how you are setting your timing and what distributor you have yet?
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[chris86uk]

Great, I'll try all that in the morning.

No, we haven't discussed timing, I haven't touched that yet. Or the distributor for that matter, I think it's a Bosch 009 but I'll have a look tomorrow.

Thanks!

[chris86uk]

Ok, just sorted the choke, that's working again now.

I removed the idle jet totally, cleaned it and replaced to the position it was in to begin with, no change. Turned it out 1/4 turn, still no change.

Cold idle is good now I've fixed the choke I messed up yesterday, but it still dies if you rev it and let it fall back to idle when it's warmed up.

My distributor is a Bosch 009 by the way.