Idle problems

[Germain]

Hello all, I have a 73 2.0L d-jet system. I've tried the idle screw, I've checked that F.I. components, and everything seams to be working correctly. Seams being the key word, the car idles at 2500 rpms. Warm or cold. (The cold start valve does not work). Anyone have any ideas? Thanks.

[Steve M]

Plug the cold start vavle and use the accelerator pedal to keep the car from dying when its cold. Thats what I do.

[Germain]

Brian, I have removed the hose from the auz air valve, and plugged it. It causes the engine to die. Any ideas?

[John Rogers]

Sounds like the aux air valve was stuck open. There should be an electrical connection to it to cause it to heat up fairly quickly and if that didn't work, engine heat will cause it to close off, but much slower. Since the engine dies now with it plugged, you can adjust the idle with the adjusting screw to get a nice 900 RPM idle. You might want to take the aux air valve out and soak it in WD40 or some other oil to see if it frees up and then try heating it with a hair dryer or put 12 volts to the lead and watch it close off. It it won't work, good luck finding one since I don't think they are made anymore? althoug I bough one for a later model Vanagon and it works okay. Ours took three days of soaking before it started to work.

[agent914]

I had the close to the same problem with my '72. At first It would idlw @ 2k - 2.5k. Then it progressively got worse. (4,000)
-Vacuum leaks were the root of the problem.
The hoses from the air intake manifold to the runners. ---Agent 914---

[Germain]

john rogers, just to get this right... When I plugged the aux air valve and the engine died you think it might be because the idle screw is wrong?
Also, does anyone have the ability to explain what the aux air valve is for, what it does? I am bound and determined to get this D-Jet F.I. system working correctly, however I have only a month of experiance with it. I refuse to go to carbs with my engine being %100 stock and original.

[Pritchard]

Germain-

Don't feel bad about not knowing all there is to know about the D-Jet system. I've been learning about it for 8 years now. I still don't know all there is to know. Most everything I have learned has come from this website. Thanks PP!

The Aux. Air Valve allows "extra" air to enter the air distributor while the engine is warming up. As the AAV heats up (the red wire coming off the bottom powers an internal heater), it will gradually close off the "extra" air being supplied.

If you haven't read Kjell Nellin's D-Jet article, you should! Go to the 914 links page on this site and look for 914 Fan Web Page. The article is in the Tech Reference section. I printed out this article and keep it in the shop/garage for easy reference.

Pritchard

[This message has been edited by Pritchard (edited 11-16-1999).]

[John Rogers]

Pritchard has it right. Probably what you did was to screw in the idle adjusting screw to try to make it idle slower? To prevent vac leaks, I cut off about 1/2 inch from each hose every spring to insure I always have snug hose joints. Good luck.