high rpm + high boost = stumble

[Martin Pajak]

Recently we had two instances of Fuel Distributors failing to provide enough
fuel under high boost/rpm
Anything above 6psi and 4k rpm the engine would go lean (fuel/air ratio
gauges) and a stumble could be felt.
Good used Fuel Distributors fixed both cases.
If you have an Ari/Fuel gauge you will be able to spot it right away.

Hope this helps.
Martin Pajak

http://www.quattro.ca

1983 Audi Ur-quattro (265,000 km) Winter car
1985 Audi Ur-quattro (141,000 km) Euro spec. import ;o)
1986 Audi 4000 S Quattro (442,000 km) with 5 bolt pattern RIP

> >My 5ktq is experiencing a stumble or mis-fire at high boost and high
> >rpms.
> >I would dearly love some advice as to how to best diagnose this
> >problem, and
> >ideas as to what the problem might be.
> >
> >High boost is 1.6 - 1.7 bar, I am running a 1.7 bar spring and no WGFV
> >input
> >to the WG.  ECU is good to 2.2 bar.
> >
> >At any rpm, under low load and low boost, the car seems fine.
> >At low rpm and high boost, that is 5th at 3000 rpm, 1.7 bar, car seems
> >to
> >run fine.
> >At high rpm, high boost, that is 3rd, 4000-6500 rpm, 1.6-1.7 bar, the
> >car
> >stumbles or mis-fires.  It's not a subtile stumble, either.
> >
> >The car is an '88 5ktq.  It has a new turbo, and the intercooler has
> >been
> >converted to single pass.  I have great confidence that there are no
> >leaks
> >in the air induction path from air cleaner to TB.  I do believe I have
> >a
> >small leak somewhere in the manifold (a hose) as my idle is now at
> >1000 or
> >so.
> >
> >What the problem is likely not:
> >I just replaced the wires, plugs and cap with new.  Plugs are: W7DTC
> >0.8mm
> >Rotor and distributor are 3 months old.
> >BOV has been removed and there are currently 2 pieces of 1" dowel in
> >place
> >of the BOV.
> >
> >I just replaced the turbo( IA RS2), timing belt and WP.  I also put in
> >new
> >injectors -- everything beyond the flare-nut fitting is new.
> >
> >The car ran fine at >1.7 bar at any rpm before I did the turbo and
> >belt and
> >injectors.
> >
> >Any thoughts are welcome and appreciated.
> >
> >Best,
> >
> >Bernard Littau
> >Woodinville, WA
> >'88 5ktq
> >
> >
> >
>