I sure wouldn't call 3K rpm 'runnaway' ..though it does sound really
dramtic to discribe it that way.
if it was really runnaway ..
it would be screaming at 6,000rpm or so.

I wouldn't think that the TPS telling the ecu that your at full throttle
would do this.
I believe all that does is bypass 02 input at WOT.

And ..I have seen the electronic control unit and/or idle air valve
cause this.
I've had a vanagon sitting in a bay of my shop idling ..
suddenly jump to very high rpm all by itself.

Unplug the Idle Air Valve right there on top of the engine.
ISV valve sometimes called too. Idle Stabilizer Valve.

Scott

On 10/10/2013 9:44 AM, John Meeks wrote:
> Yesterday I was in a 2 mile stop and go traffic jam. About 3/4 of the way
> the low speed fan came on as expected. A minute later the engine revved up
> tp 3K rpm and stayed there. The gas pedal was all the way up. Couldn't get
> off the road so I turned off the engine when there was a stop situation.
> Turning it back on the engine revved right up to 3K again.
>
> Finally pulled into a parking lot and waited about 15 minutes. Started
> normally with no recurrence the rest of the way home.
>
> I had this same problem about a year ago (intermittant) and 'fixed' it with
> a new throttle cable and cleaning out the rust and dirt from the pedal to
> cable housing. Now it's back!
>
> Side note  just put the engine in after head gaskets and ring replacment
> and It was running great for the past week.
>
> Could the TPS be the culprit if it made the ECU see full throttle and ECU
> then enriched the mixture?
>
> Any ideas are welcome.
>
> John Meeks
> '91 Vanagon MV Phoenix
> Stock 2.1 250K miles
> Northern Michigan
>
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>