Re: Idle Control

[knut.s.grimsrud@xxxx]

You didn't mention in your post that you were actually experiencing 
any idle control problems with your car, so I'm wondering what the 
actual problem you are trying to solve is.

It is true that when cold the DeLorean idle has a tendency to 
oscillate/surge. This is fairly typical for the car(although neither 
of my cars oscillate like this as this tendency can be tuned out). 
This is actually not due to the idle speed control system at all, but 
due to the lambda mixture enrichment system oscillating at cool 
temperatures. The response time of the oxygen sensor in the exhaust 
system is a bit slow when the sensor is cold and the result is that 
the mixture control system has a tendency to oscillate between lean 
and rich because the sensor is not responding well. Once the system 
warms up a bit the oscillation tendency usually goes away.

Although the surging at low temperatures might be a little annoying, 
it does not have any real adverse impact and should only last a few 
minutes during warmup. I'm not aware of any real deficiency in the 
Bosch idle speed control system and have never heard of this as being 
a high failure rate item (DMC Joe seems to have failure rate data on 
all the components in the car). The only common problem that I recall 
being covered on the list have to do with corrosion of the 
connections to the idle speed regulator -- something I'm sure a 
Japanese unit is not immune to.

Knut


--- In dmcnews@xxxx, wmack <wmack@xxxx> wrote:
<snip>

> about it. However, he did tell me that he was a little concerned 
with the way 
> the car was idling. He began to give me his two cents on the 
subject, and 
> told me that european car manufacturers can't seem to make a good 
idle control 
> system.