cold start problem

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

In message <19971110174552.AAA22104@LOCALNAME> Vincent Mak writes:

> My 87 5000CST developed a cold start problem recently.  The car would start
> up fine if the outdoor temperature is approx. above 60F. but won't start if
> it is chilly outside.

Just debugged one of these on Roger Galvin's Coupe quattro.

Dead warm-up regulator (a.k.a. control pressure regulator).

I put the fuel pressure gauge on and started the fuel pump with a jumper from 
the battery.  Control pressure was 0.5 bar at first, _very_ gradually 
increasing to around 3 bar.  Once the warm-up regulator was warm, the engine 
started first time, every time.  I can imagine that this problem is very 
sensitive to ambient temperatures.

-- 
 Phil Payne
 Committee Member, UK Audi [ur-]quattro Owners Club