2.1 Auto stalling

Post by **john davis** » 15 Aug 2008, 21:32

Hi

My 1990 Auto 2.1 petrol injected (DJ Digijet) has started stalling from time to time when pulling up at junctions etc. Doesn't do it all the time but it seems to me that the idle speed is a bit low. It was time for a service anyway so changed the plugs and had a good look round. Nothing obvious except a lot of gunge on the throttle valve spring which I cleaned up. Did notice that the throttle valve adjustment plate was cacked up so cleaned it and noticed that the adjustment screw seemed to be loose and wasn't any sort I'd seen before, nothing I have fits it, could be messed up....the securing screw was a simple Allen. I'm wondering if the adjustment screw should have been/once was similar?

I'm at a bit of a loss and did wonder whether to tweak the throttle valve basic setting screw to get a bit faster idle that way? Haynes manual says don't touch it (in bold letters!)...what does anyone think? If it was a manual I could drop the clutch and stop the stall from happening...obviously can't do it with an auto. Anyone else had this sort of problem? Solution?

Thanks

John

Post by **funbus3** » 17 Aug 2008, 19:02

Our stalling/idleing problems were caused by the idle switch on the throttle body being full of gunk and not properly ajusted.

Both the securing and ajusting screws are both standard allen type, a quick clean & tweak a la Mr Haynes and she runs like a dream!

Post by **ELVIS** » 17 Aug 2008, 19:32

Take off idle stablisation valve ( right on top in middle of engine , is tube shaped and about 1" thick and about 5" long. has a small electrical plug on one end that pulls off and a hose on the other end that pulls off easy aswell). get a can of carb cleaner and really give it a good clean out- you will be surprised at the gunk that comes out.
Take the airbox off and take the whole throttle body off. (crosshead bold/screw at 3 and 9 o'clock. is a bit tight but comes off easy. dont forget to disconnect various hoses/plugs from airbox to make removal easy). Give inside the throttle body a good ole clean with carb cleaner aswell.
on the side of the throttle body nearest the front of the bus , there is a small grub screw (the head of it is accessed from drivers side) it should not have been tampered with from the factory , if it has - use a piece of paper (normal writing paper worked for me) and slide this between the bottom of the grub screw and the part of the throttle body it touches /rests against and use this as a feeler guage . this is near as damn it same as factory setting.(cant finder feeler guage size, sorry) .
Idle is adjusted by the flat head screw on front of throttle body (recessed screw head size of a penny) . On the airflow meter there SHOULD be a cap the size of a penny , if this is missing you will see a recessed allen head screw. DONT touch this , its the CO2 screw.

Post by **john davis** » 18 Aug 2008, 09:55

Hi Funbus and Elvis...

Funbus...I think the adjusting allen screw on the idle switch has been knackered at some point, for a start it's just like a very small piece of loose drinking straw, ie circular inside. As I said before, the securing screw is fine. Not sure what to do about that; will take the throttle body off and see what's what.

Elvis...couldn't see (or didn't notice!) that penny-sized flat recessed screw on the throttle body; will have another look when the weather improves. I'm assuming that the throttle body you refer to after removing the air filter and air flow meter is the same as the throttle valve/idle switch assembly that Funbus is referring to? If that's the case and that recessed penny-sized screw is there..what's the relationship between the idle switch adjustment and the idle screw adjustment? Which should be done first?

Sorry Elvis to sound ignorant but I couldn't find the idle screw adjustment point shown on fig 8.14 on page 1.10 of Haynes. From that line drawing, it looks to be different from the idle switch adjustment screw? Am I right in that? My van is one of the very last to be made and I've discovered a number of things that don't match up with the Haynes.

Will report back when I can get onto it again.

Thanks for your suggestions

John

Post by **ELVIS** » 18 Aug 2008, 13:38

just in middle of decorating - will nip out early tonite and take some pics for you

Post by **john davis** » 20 Aug 2008, 19:18

Hi Funbus & Elvis

I think/hope/pray that I've got the stalling and idle speed sorted out...so far so good. Thanks for your help.

Can I beg your indulgence once more. Please can you tell me what is the function of the long spring connected to the top of the throttle valve. It doesn't seem to perform any function, unless it's to return the throttle cable to idle perhaps? I was wondering whether I could leave it off as it makes the throttle peddle a bit smoother to operate.

[img:320:240]http://www.jdavis.org.uk/spring.jpg[/img]

Cheers

John

Post by **kevtherev** » 20 Aug 2008, 19:23

John
you have to host your picture on the internet.
www.photobucket.com is free to join
upload your picture to them and use the [img] code they give you, and paste it in the reply box

Post by **john davis** » 20 Aug 2008, 19:30

Hi Kev

Sorry about that...it's on my own webspace but I forgot to put the jpg suffix in my post!

Cheers

John

Post by **ELVIS** » 20 Aug 2008, 20:26

soz bout pics , was decorating til gone 9 last night.
If you ever find out what its for let me know . phoned up VW yesterday as my spring appears VERY loose/saggy/stretched/dead - it is now obsolete!
im guessing its something to do with smoothing the closure action of the throttle body so it dosnt snap shut . Only a stab in the dark though!
what was the problem with the idle etc in the end ? what cured it?

Post by **john davis** » 21 Aug 2008, 08:04

Hi Elvis

No problem. What I did was take off the idle stabilisation valve and clean it through with carb cleaner, shake out the air filter element and adjust the throttle valve switch as best as I could a la Haynes....the adjusting screw is really tatty. Then it was a case of smoothing out the idle speed with that biggish screw in the centre of the pic. I didn't knew it was the idle speed screw, on all my other vehicles it has been tiny...I thought it was a mounting bolt!! Anyway, all seems well now.

Like you, no real idea what that long spring's for though...it doesn't seem to make any difference to the running.

Thanks again

John