re. need help setting up Blaufergnugen 272 cam in 86 4000Q

[Huw Powell]

> I found once I set the cam advance to where I thought it should be -
> depending upon whether I wanted to pass emissions or go fast, that
> I'd have to play with the timing to get the engine marginally happy.

That reminds me, you should start this playing with the timing set 
closer to stock, I think.  Once you get a better idle and low rpm 
performance ("acceptable" might be all you get), then see what you can 
get by turning the distributor.

I suspect that overlap issue Ben mentioned might also affect the vacuum 
advance system, so you never know, you might get better on-throttle 
action with even more static advance - as long as you can keep an idle 
of some sort.

> You may also want to check all of your idle stabilization gadgets,
> including the throttle adjustment screw, throttle body and plate for
> sticking, the funky hose that looks like an intestinal tract, the
> switches as well as the ISV - should not pass air AFAIK when not
> energized (different than the 3 wire NG ISV).  Any of those can cause
> the problems you describe as well.

Agreed - it sounds as though you've been giving the engine a fairly 
thorough "going over," but it's easy to neglect some of the little 
hoses, which are all designed to leak in invisible places when they go bad.

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/