MB owners - a question

[Phil@isham-research.demon.co.uk (Phil Payne)]

In message <34062AC7.7002@mail.steelcity.net> turbo@mail.steelcity.net writes:

> > (We're still trying to debug John Robinson's problems.)

> E-mail me with more info I have Audi literature at my disposal.I need
> vin# and also I missed the original problem you were having let me know
> what it is maybe I can help.

The problem is aggressive leaning-out at high power - it starts at 4500
rpm and the engine won't reach redline in fourth on the flat.  It will
cheerfully pull hard to redline in first and second, but in third it
starts to get reluctant.  The engine has done 160k, and was rebuilt by
BR Motorsport about five months ago.  Some gas-flowing was done, and a
smaller (RS2) turbo fitted.  John and I have stripped and rebuilt the
fuel metering system, and it passes all of the documented tests as
regards pressures and flows.

We have the factory microfiche for the ur-quattro, but the MB engine is
not completely documented.  Yesterday I stripped out, desoldered, tested
and cleaned the inlet air temperature sensor, which is mounted on the
intercooler on the MB.  One of the leads broke off very readily, so I'm
hoping it was presenting too high a resistance to the ECU.  Off the car,
it was 498 ohms - well within the 400 to 700 ohm specs.

(BTW - brake pipe clamps are _ideal_ for holding back the yellow cable
 shrounds when you're soldering.)

I think I'll rig my hoses as his are done, and see if that gives me the
same problem.  We're not seeing any boost problems, though.  He has a
calibrated boost gauge mounted on the dash, and I've checked it against
my hand-held 8" dial instrument.

It's nice having two virtually identical cars to play with - we can
swap parts from one to the other.  Yesterday, we swapped his idle
controller into my car and discovered that the 'rolling high idle'
function _is_ there with his controller.  He doesn't have the function
when it's in his car, so we have at least one wiring delta to check
alongside the hose delta.

--
 Phil Payne
 phil@isham-research.demon.co.uk
 Phone: +44 385302803  Fax: +44 1536723021  CIS: 100012,1660