Re: Rich Fuel mix with High Idle

[dherv10@xxxx]

Rustproof, How many miles are on the car. Cat's will stop up and 
restrict flow. When this happens it will also beging to glow. If the 
Air flow and or gas mixture hasn't been kept up correct, then the 
cat's can be stopped up. If you do mechanic work, you may want to 
pull off the throttle boby and clean out all the gunk that will build 
up inside. If the butterflies in the throttle body don't close all 
way that too will cause an improper air mixture. David is right about 
the Air Flow Meter and it's adjustments. You have to keep these cars 
tuned. Theres no one computer to do it. When was the last time the 02 
sensor was changed and you say the Lambda System working. Put a can 
of Berrymans B12 in the gas and go drive the car. If there is any 
varnish in the system, it will desolve it. 
John Hervey
http://specialtauto.com/

--- In dmcnews@xxxx, "Rustproof" <Rustproof@xxxx> wrote:
> I am having some trouble locating the cause of a high idle 
condition (2000 rpm) and an extremely rich fuel mixture. The mixture 
is so rich that the catalytic converter will begin to glow. I have 
checked the ECU and O2 sensor with an o-scope and find that the 
signal and duty cycle are within normal operating parameters. The 
frequency valve seems to be operating normaly as well. All of the 
extra adjustment screws are seated to allow for the ECU to do its 
job. The Idle control air valve seems to be operating OK and is not 
sticking. No leaks at the cold start valve. The idle switch is is OK 
too. The fuel injectors are all operating with a good spray pattern 
and have been checked for equal fuel distribution. I am running out 
of ideas. Has anyone run into this sort of thing before? Thanks in 
advance for any suggestions you guys may have.....
> Rustproof
> Vin #1559
> 
> 
> [Non-text portions of this message have been removed]