Re: [T3] idle problems

["Jim Adney" <jadney@vwtype3.org>]

On 5 Mar 00, at 21:05, Seldom wrote:

> The vehicle:
> 70 Fastback 85K original miles, AT, F/I

> The status:
> Replacing the voltage regulator made a huge difference
> with the richness problem so now the car runs well
> under load, but the hunting remains.

> The details:
> - Fuel pressure is at 30 PSI
> - I've adjusted the throttle valve, and it seems to be
> functioning properly 
> - resistance for temperature sensor I & II seem to be
> within specs, both when warm and cold
> - auxiliary air regulator seems to be working OK
> although there is a very slight vacuum, even when the
> car is fully warmed up. 

These all sound perfectly normal.

> - The idle adjustment screw has no apparent affect
> (vacuum leak I thought!) but
> - Hoses seem to be in OK shape - I'll replace them
> next.  In any case, I haven't been able to find any
> obvious vacuum leaks.

Places to check: intake manifold gaskets, pressure sensor 
diaphram. One way to check is with a propane torch (unlit); when 
the engine sucks in propane instead of air, the richness changes 
and you can note the change in the engine.

Having changed the VR you should also change the oil now, and 
just getting it running and warm will often have good effects. Make 
sure that the thermostat is connected and operating correctly. If 
the engine can't warm up, it can't burn off all the carbon that has 
accumulated.
 
-
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054

-------------------------------------------------------------------
List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org