Hi,

I have an 1989 Audi 500 (South African name for the Audi 100 with 5cyl
2.2 engine), . Recently, someone checked out the fuel injection
system. He said, the pressure of the warm-up regulator was about 0.5
bar too high (4.2 bar instead of 3.6 to 3.8, iirc). He said this would
make the fuel mixture too lean, but a replacement regulator would cost
a lot. He then adjusted CO at idle and just said that's the best he
could do.

My questions:

- Is there any way that we could adjust the pressure on this warm-up
regulator?

- How big is the effect of a too high pressure, and what are the
consequences?

He said the the performance would be a bit lower than originally, but
insisted that the fuel consumption should be lower as well, if
anything. That doesn't sound right to me. With a 120 km/h general
speed limit, I will not go full speed anyway. If I want to go at a
certain speed (like 120 km/h), I would obviously press the acelorator
to the required level to maintain this speed. I would assume that the
fuel consumption is only optimum, when the mixture is optimum.

Any other effects, or should I not bother about it?

Thanks for your help,

Christoph