High Revs now won't idle 2.1 DJ Injection

[rustyrat]

Hi all,

Just got back from Kent VW festival & literally as I pull up outside my house my van just started revving up to 3500rpm, first though maybe the throttle cable/throttle butterfly had got jammed quickly unpacked everything out the back & checked but all was moving freely. Tried to restart & found that the engine will no longer idle, it will run if I give it a little throttle, but as soon as pedal released engine cuts out again no idle.

I've read a few posts re: vangon syndrome & problems with this injection set up cutting out when driving, but I've not found another post with these exact symptoms. So was wondering if anyone had any pointers before I head out with me spanners & multimeter

I'm thinking possible idle control unit, throttle switch, elec connections or worse case the AFM

It's 1990 bus fitted with late 2.1 DJ engine (twin oil pressure sensor) running standard digijet injection.

Any suggestion greatly appreciated

[rustyrat]

Ok after having a quick play this morning tested idle control valve resistance it was spot on, checked throttle switch operation this is fine too, checked wiring from both of these to idle stabilization control unit ok also checked all resistances on the AFM which are within spec according to haynes manual. removed the ISCU and noticed it seems to been opened up before. So I've opened it up again to look inside & found one of the square resistor in side burnt out see pics sorry bit blurry Im no photographer .

So just got to source a new one now or get this repaired.

part number on mine is : VW - 251 907 393A or VDO - 412.202/015/003

If anyone has a good one kicking about they would like to sell please pm me or post message cheers

Hope this post maybe of some help to anyone with same problem.

[rustyrat]

Last update, just fitted second hand idle control unit. Started first time ticks over great no other adjustments needed even thou fitted later model part ending in C.

Back on the road again.

[REGGAJ]

Nice 1