1981 VW caddy high idle.

[Danny]

I think my aar may be stuck open.

[Ryann]

Easy test. Let the engine warm up, then completely pinch off the rubber line between the valve and the intake manifold.

[Danny]

It doesn't really warm up though, and when I do pinch the line, nothing happens.

[der affe]

you might want to invest in a narrow band gauge also. that way you can get an idea of what you are ending up with when you adjust the screw.

before you go messing with the idle speed screw, check the injector cup seals and put new injector seal o rings on them ( the injector o rings are super cheap) and pull the injector bosses out and check the flat o ring seals (they are always over looked when new o rings are put on the injectors)
you will need a large allen wrench to unscrew them.

maek 100% sure you have no intake leaks, before you go adjusting the idle speed and idle mixtures as it will just need you to adjust again after you fix the leaks.

[Ryann]

before you go messing with the idle speed screw, check the injector cup seals and put new injector seal o rings on them ( the injector o rings are super cheap) and pull the injector bosses out and check the flat o ring seals (they are always over looked when new o rings are put on the injectors)
you will need a large allen wrench to unscrew them.

Every Rabbit I've owned needed this when I bought it.

[delatlanta1281]

Every Rabbit I've owned needed this when I bought it.

Truth.

[Danny]

I am getting seriously frustrated, nothing I do changes anything. I have basically deleted the AAR valve and have taken out and cleaned the injectors and siliconed around the o-rings (which were in like new condition) and the God damned idle just stays at 2000 rpms. No switch whatsoever.

I have no idea what to do next. Any help?

[Eecen]

Engine swap?

[Danny]

Nay, I just want it to be running right.

[Massive Lee]

Did you set the fuel mixture yet with the 3mm Allen rod?

[Danny]

I can't it is unpossible. The screw is way too stripped.

[Ryann]

Undo the clamp around the rubber intake boot, loosen and remove the banjo bolts/crush washers at all the fuel connections, disconnect the electrical connector from the white plastic valve between the fender and the injection unit, then remove the injection unit/airbox from the car. Separate the upper aluminum portion from the lower plastic portion. Is there a fuel stain on the air filter below the distributor? Carefully flip it over and remove the aluminum arm and plate assembly. Pull the plunger from the center of the distributor and look at it. Did it slide right out? Does it have ridges or sludge on it? Clean everything completely. Reassemble and flip back over. Does the plate/arm assy. move smoothly and freely? Does it drop all the way down?

[Massive Lee]

K Jetronic uses a heated bi-wire idle valve that adds air when wire is cold. Normal position is open (allowing extra air in). Then the valve shuts down as the wire expands from being heated by the car's 12v. Is the valve still working? Could it be staying open?

[Ryann]

K Jetronic uses a heated bi-wire idle valve that adds air when wire is cold. Normal position is open (allowing extra air in). Then the valve shuts down as the wire expands from being heated by the car's 12v. Is the valve still working? Could it be staying open?

Yeah, that's the aux. air valve. he removed and plugged up that system completely. There's another bi-metal device on the front side of the block that uses fuel pressure to make it easier for the plate in the injection unit to move with airflow- might be stuck in warm-up mode.

[Danny]

How far down is the plate supposed to drop? It sits right at the bottom of the cone but if I push on it it goes down farther.