Club 80-90 Forums

Yes good call big herb... Once this pull down unit has been replaced. A stiff bristle poked into the jet will do no harm... (Using a steel pin ot needle would, so don't)

The way this is going I would suggest that you get somebody who really understands these motors to check the problem out for you, before you start spending money on things that it may not be or tinkering in a way that makes the problem worse.

My local garage mechanic has saved me a furtune by ignoring my assumptions and solving the problem at minimal cost to me. Just a thought.
Patrick

PRD wrote:The way this is going I would suggest that you get somebody who really understands these motors to check the problem out for you, before you start spending money on things that it may not be or tinkering in a way that makes the problem worse.

OK dplum Better not buy that part then mate, Patrick seems to think I don't really understand these motors.
I should do as he says instead and get the part checked at a garage that knows these motors.
when you've done that you can fit it with confidence.

personally I would suggest it's a straightforward check, as published ..... "remove choke pull down unit hose from carb body and suck, if air can be contentiously be sucked then the unit has failed, with no repair possible."
from haynes.. "If there is no resistance to closing the choke valve the unit has failed or there is an air leak into the vacuum supply."

it goes on to list air leaks as a reason for stalling and poor idle

Hi just to ad to thread as this is exactly my problem with my Bus....
Many people have helped me on here and yes with some tinkering i found various problems 1 being Choke pull down unit all done working fine and replaced for £33 from Brickwerks (recomended by Kev ) after this being sorted and gasket and filter changes all helped and resolved my stalling issue.

However i have after 4 days of perfect running been having the same problem and i have removed Idle valve cleared it out aswell as the filter housed on the fuel inlet to carb .. all are clear and fine!

I do believe thou that many people seem to experience this problem with the T25's and there could be many reasons for the stalling/bad idle to occur (i have a Haynes Carb manual could be internal dirt blocking main jets intermittent stalling put down to this would require complete rebuild/cleaning whole carb ) But thankfully i will work through them until i sort it permanently before i opt for rebuild!

Im just thankful that the advise i have received on here has possibly saved me a fortune in mechanic costs that i could have incurred in the process of eliminating the possibilities as it is not a straight forward diagnosis ... next thing i will be checking out is the Part Load enrichment (power valve)...

Novice in need wrote:Hi just to ad to thread as this is exactly my problem with my Bus....
Many people have helped me on here and yes with some tinkering i found various problems 1 being Choke pull down unit all done working fine and replaced for £33 from Brickwerks (recomended by Kev ) after this being sorted and gasket and filter changes all helped and resolved my stalling issue.

This is the first time I have had a chance to look on the forum this week since the last few reply posts - well I have brought the choke pull down unit now anyway and was looking to fit it this weekend, so I will get on with it regardless!
Just wondered 'novice in need' (or anyone else) - can you tell me how you fitted the pull down unit? As usual the haynes manual is vague on the one thing i need It seems like it should be a fairly simple removal and replacement, but the last thing i want to do is make the stalling worse!

If its a no go, then i think it will definitely be a trip down the mechanics, but i think its always good to have a go and try and save some cash first! especially with all the excellent help given on here - thanks guys!

Hi dplum
The choke pull down unit isnt bad to replace, i done it with the carb fully taken out, however it can be done whilst it is in situ after taking the pancake duct off .

Theres a pin you need to knock out (i used a small steel rod) at the front of the carb right handside which holds the choke pull down unit in place, check pictures Kev put up its visible next to the choke pull down unit itself.

Then you need to remove the Bi metal housing on the right of the carb fixed on with 3 screws (make note of the markings on housing for when you put it back together) you will see scored lines. after this the actual choke housing comes off but just enough to get at the choke pull down unit. Basically the whole unit on the right of the carb needs to com off with the water pipes going to it, check pic.

Then you have to look at it from the side and should see at the back a star clip retaining the diaphram arm, this carefully pull off with thin nosed pliers as i did, there you go you can remove choke pull down unit, i ensured that the screw in the old one which adjusts it (at the back) i replicated the depth on the new one i was fitting.

It really isnt that complicated as it sounds, hope this helps.

I unfortunatelly still have the stalling problem thou even after ..
solenoid check and wires
Choke pull down unit replaced
Filters changed, both which did help for a while!
All vacum hoses changed
Manifold gasket changed
servo brakehose checked and is fine
Power valve seems ok too, diaphram looks ok too but i may change if i cant find anything else it could be
idle jet checked and ok
So im still hoping it isnt a block main fuel jet as this will defo mean a rebuild... if you can keep us upto date with your progress id appreciate it ......

Hi just to keep you informed so that you can thoroughly check your solenoid switch wirering ... i found today that the plug part which pushes into the solenoid is rather worn and hence the bad connection which after replacing has resolved my intermittent stalling probs.... hope this helps dplun

O cost minimal .... satisfaction that i sorted it PRICELESS !!!

Well i guess i hav been hasty as my stalling is still evident after a couple of days good running, iv decided tha it may be a defective solenoid cut off valve, so here goes another attempt

Hi Dplum ... whilst i noted that you havent been back as yet, i thought id just leave this so that if you do come back it may help.
After Chokepull down replacement, manifold gasket replaced, spark plugs, vacum hoses and fuel filters also spade connectors to fuel cut off valve i believe the problem is finally resolved - it appears that the connection on the dizzy underneath the distributor cap which clips on was loose, since re attaching and making sure its tight as the metal clip seems a little worn i have had no stalling all day, hope this basic check helps!

'Novice in need' thanks for all your help and suggestions. I must admit I haven't had a chance to finish off even fitting the choke pull down unit yet - I got halfway last wekeend then had to go out, its bloody dark everyday by the time i get home from work and we are busy again this wekeend, so it will probably be next wekeend before i get a chance - grrr...... I can't wait til summer and those long light evenings!

I have printed off the long list of suggestions from everyone and will work my way through them one by one.

Glad to hear your's is up and running ok again - I know how you feel when you think you've solved something and then 3 days later the old problem comes back!

anyway thanks for all your help, and I will keep informed when i finally get to have another crack at it.
cheers

finally had a chance to fit new choke pull down unit now and check other aspects, but lo and behold its still not ticking over and is needing a good load of revs to keep it from dying and on start up.
so far I have:

checked pilot jet - ok
changed fuel filter underneath van and cleaned filer in the carb
fitted a new choke pull down unit
air filter is fairly new and clean
new spark plugs
brake servo hose replaced and new jubilee clips keeping all air tight
all hoses checked and fine
fuel cut off valve appears fine

is there anything to check, especially with the carb?

thanks

Is the tick over screw in contact with the throttle stop?

try turning it in until the engine ticks over

I see it is recommended to detach the choke housing prior to replacing the choke pull down unit. Does require the coolant system to be drained?

Cheers,
Tim

actually, you dont need to take it off at all - with the air intake off, there's plenty of room to get it in next to the fast idle cam.