D.I.S.??

Hi,
The DIS box on my car appears to be missing?!
The wires are there, but joined together just like in the picture in the Haynes manual on how to tune the engine.
Is this why my idle is so bad on starting from cold? Or is that more likely to be the warmup regulator thingy?

My car is a 1983 1.8 dx non campaign gti
Should this have a dis box? Or am i just wrong!?

Are they still available?

My 83 GTI is the same. It has the connectors but no DIS unit. It idles fine so I think you probably have a fault somewhere else :?.

The Digital Idle Stabilisation box basically keeps the idle stable if there is a heavy load placed on the electrical system, like if you were to use your rear window demister, full beam etc. Not something you are really going to notice much so I guess VW decided not to fit them in the end :dontknow: Maybe both our cars have them missing! :dontknow:

Damn it! So its gonna be the ?165 jobbie from gfs then?! :x

Liam said

Damn it! So its gonna be the ?165 jobbie from gfs then?! :x

??

So whats wrong with your idle? are the revs too low? Could it be the Aux Air Valve at the back of the inlet manifold? Have you done the fault finding in the haynes?

Very very very low on cold starting for about 2 mins.
Checked the aux air valve and this seems to be working ok.
Altered the isle speed, but this only helps slighty - when warm it idles at aprrox 1250 revs, when i tuned it up i set it to 900 revs, but when it was cold again it would stall constantly!
So i assume it's the warm up reg if the dis wouldn't solve the problem?

?165 from gsf  8O  i bought one from vw 3 years ago and it was only just over ?100, got a few spare btw  :wink:

Hmm, so you squeezed the tube from the AAV and the revs dropped even further?

I'm not brilliant at diagnosing fuel inj problems but i'd have another look at this maybe? Is there voltage to it etc?

You could always borrow some parts from crazyquiff or someone to diagnose the problem

Sounds very much like the auxiliary air valve to me, warm the car up, make sure its been run for 10 minutes, now pinch tight the hose leading from the auxiliary air valve to the inlet manifold, if the idle drops it meens that the valve isnt working, next stage is to check that the valve is getting a voltage, if it is then its the valve, if its not trace the wiring back to the fusebox, i did have one car where it was disconected, shall assume by mistake whilst working behind the fusebox

storm 81, if the car has run for 10min and you pinch the hose the idle should NOT drop as the auxiliary valve is supposed to be closed already.
At least in this warm weather!

You should test if the valve is working properly when the engine is cold, if you then pinch the hose the idle should drop.

greets yal

I tested it earlier this year, in the colder months!
I took the big plastic intake off from the air filter to the throttle body, and covered the aav tube with my thumb, the car then stalled. Repeated this several times. This led me to belive that the valve was working ok?

You don't need to remove anything to check it. Just pinch shut the tube that runs over the top of the inlet manifold by the cold start valve.

yal said

storm 81, if the car has run for 10min and you pinch the hose the idle should NOT drop as the auxiliary valve is supposed to be closed already.
At least in this warm weather!

You should test if the valve is working properly when the engine is cold, if you then pinch the hose the idle should drop.

greets yal

Actualy mate the valve is fully open from cold and if working properly will close over 5 minutes, if its not working then the idle will drop when the hose is pinched as the valve will be fully open even when the car is fully warmed up, testing when cold meens nothing as the valve is always open when cold as its closed by a bi metalic strip

testing when cold meens nothing as the valve is always open when cold as its closed by a bi metalic strip

Unless of course it is stuck shut! I think this is a common fault with an AAV is it not?

Ross, thats what I was thinking! Twice I had one that was stuck shut and therefore I had no idle when cold.

greets yal

I have yet to come accross one that has been stuck shut, most common problem i come accross is they are stuck open which gives you normal idle when cold but a high idle once warm

So I guess the best way to problem solve it might be to just follow the test procedure in the Haynes!