Date:         Mon, 22 Apr 2002 14:42:55 -0500
Reply-To:     John Rodgers <jhrodgers@MINDSPRING.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         John Rodgers <jhrodgers@MINDSPRING.COM>
Subject:      Re: More idle questions (no pun intended)...
Comments: To: WVVW <wvveedub@NETSCAPE.NET>
Content-Type: text/plain; charset=us-ascii

WVVW wrote:

> Additionally, when the engine is cold, it idles beautifully for about 5 seconds, then drops down to around 250 RPM, chug-chugs for about 2 - 3 seconds before dying all together.  If I try to tap the accellerator to bring it back up when it is chugging, it quits.  However, I found that if I can catch it while it is running good, or just starting to die, I can hold it at about 1200 - 1500 RPM until it starts to warm up, then start off. Whether the idle stabilizer is bypassed or not, the engine runs the same.
>
> When the engine is only 'luke warm', it idles erratically, but when it is at operating temperature, it idles rather nicely.
>
> To date, here is what I have fixed / replaced:
>
> Air flow meter (new)
> Distributor (rebuilt bosch)
> Cap and rotor (bosch)
> plug wires (OEM with shield)
> plugs (bosch platinum)
> vacuum lines
>

I take it your van has a WBX engine. If so, you need to do a set-up of the basic idle speed of the engine. Do this with a thoroughly warm engine, idle speed stabilizer disconnedted. Adjust your idle speed screw right or left until the idle speed is stable about 850-900 rpm. shut the engine off, reconnect the stabilizer. Start up and check performance. Then stop the engine, let it cool, then make a cold start and check performance. Gotta have that idle speed right in for the controls for the power steering
pump, AC and cold idle to work properly. The AC when turned on utilizes the ISV to ramp up the engine rpm to prevent the engine from stalling under compressor load. The switch on the power steering utilizes the ISV to increase rpm when the limits of turning are reached and the pump loads up, and finally, but porbably first, the ISV functions to set up rpm so engine won't stall on a cold start. Once the engine is warm, the temp II sensor tells the ECU the engine is warm, and to cut the ISV out of the circuit.

You did not mention the Temp II sensor in your list of replacements. I would be suspect of a faulty senaor. Cheap, easy to replace, an extra should always be in the spare parts box on trips. They do act up and also will quit sotne cold dead.

Good luck on your hunt.

John Rodgers
88 GL Driver