feul injectors

[quk@sievers.com (Phil Payne)]

In message <199706040203.MAA10351@morden.netpci.com> "Mark&Michelle Sousa" writes:

> 1. How can you isolate a faulty fuel injector?

The factory microfiche describes pulling the injectors out, inserting them into
five plastic measuring cylinders held in a special frame, and triggering the 
fuel pump.  There should be a "ball like" spray pattern, and the amount 
dispensed by each should be roughly the same.  I only have the actual figures 
for the UK ur-quattro engines.
 
If there is a marked discrepancy, the microfiche says to swap the lowest and 
highest delivering injectors so as to check if the problem is in the injector 
or in the fuel line to it.

There is a volume test using a service tool or a depth gauge to move the air 
mass sensor a specific distance and look for the higher volume that should 
result.

> 2. How do you know if your cold start valve is bad?

Pull it, and actuate it into a glass.  There's a discrepancy of opinion here - 
the factory documentation says that the spray pattern is critical, and many 
experienced list members say it doesn't matter a damn.

> 1. Hesitating startup.
> 
> 2. Carbon fouled plugs
> 
> 3. Heavy black soot build-up on exhaust

General health.  Start by looking for air leaks - clamp the breathers, etc., 
and then put a gauge on the warm-up regulator and check for proper operation.
 
It sounds like the car has been set over-rich at idle to compensate for 
something that really should have been addressed properly.

--
 Phil Payne
 phil@sievers.com
 Committee Member, UK Audi [ur-]quattro Owners Club