Air metering valve - MC-2

[isham-research.freeserve.co.uk at pop.pol.net.uk]

>>>  One of the many outstanding jobs on Puff the Magic
>>>  Wagon is the
>>>  replacement of the fuel metering head.  I've had the
>>>  typical symptoms
>>>  of upper O-ring failure for some time.

>> What are they?

> Phil, posted this to the list, but didn't get a real conclusive
> response. I too am interested in what the symptoms of upper o-ring
> failure are. The symptyms of my car are detailed below.

> I'm wondering this as well, as I'm suffering some symptoms that seem
> to be metering head related on my 1987 5kcstq.

> Symptoms are: Occasional miss at idle (maybe not related to the other
> problem), and (seemingly) a miss at >3000 rpm under higher throttle
> settings. Sometimes it pulls beautifully from idle to 6500, and
> sometimes it hits a wall at 3000-4000. Other times it's less severe,
> manifesting itself as a weakness in the upper rpm range. The miss
> isn't like a bad plug wire, where you have a regular sharp kind of
> vibration, but rather a sort of random misfire. Fuel pump and
> injectors are recent.

Sounds a reasonable fit.  Metering heads are expensive - do you have  a
local rebuilder/refurbisher?  Around here it costs about GBP200 to have
a metering head rebuilt.  I would think it's about time for the job to
be done on a 1987 car.

--
 Phil Payne
 http://www.isham-research.freeserve.co.uk/quattro
 Phone +44 7785 302803   Fax: +44 7785 309674