cold start weirdness

[Huw Powell]

>  I dont understand why leaky injectors would cause this problem. Are you
> saying that residual fuel pressure is the problem . .the injectors bleed off
> the pressure over time?

Yes.

> If you turn ignition on, but dont start the engine. Does'nt the fuel pump
> pressurize the system?

No... although, yes, the fuel pump typically kicks on with these cars 
for a second or so, it is *not* a feature, it is a bug.  As Ti, I think, 
pointed out a few months ago, it's a by-product of the coil connection 
to the FPR telling it to run/not run depending on whether the engine is 
still turning and firing.  There tends to be a pulse from the coil at 
turn on (and off), resulting in a short burst of fuel pump operation.

It's not enough to pressurize the entire system if all the residual 
pressure has bled off via leaky injectors (or a flaky check valve).

At the same time as wiring that temporary CSV controller, it would make 
sense to monitor the fuel pump operation with a small light, and also to 
add a bypass switch to try running it for longer, say 10-20 seconds, to 
see if that relieves the problem a bit.  Then properly fix whatever 
makes that a temporary "fix."

-- 
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/