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V8 3.9 Idle mixture 1998
Posted: Thu May 13, 2004 2:51 pm
by bazzle
Has any one adj this sucessfully?
What size allen key, in or out for leaner?
Steps?
Bazzle
Posted: Thu May 13, 2004 3:08 pm
by GRIMACE
I have sucessfully adjusted this on my 89 RR but unfortunately cant help you as i can tremember which way (clockwise or anti clockwise) was richer.... nor did i even take note of the allen key size (which could be different on your vehicle)
Sorry
i couldnt help
Anthony
Posted: Thu May 13, 2004 4:02 pm
by carmino
The mixture screw on a 98 disco is in the airflow metre under the little rubber plug. DONT TOUCH IT. It cannot be adjusted without haveing the car on an engine analyser, without one you will damage the airflow metre and they are about $1000 to replace. Ask me how I know.
The allen key screw near the throttle linkage is for adjusting the idle speed and there is a special way of adjusting it also.
Posted: Thu May 13, 2004 7:19 pm
by Rovernaut
carmino wrote:The mixture screw on a 98 disco is in the airflow metre under the little rubber plug. DONT TOUCH IT. It cannot be adjusted without haveing the car on an engine analyser, without one you will damage the airflow metre and they are about $1000 to replace. Ask me how I know.
The allen key screw near the throttle linkage is for adjusting the idle speed and there is a special way of adjusting it also.
What Carmino is descibing is the Base Idle screw setting near the throttle linkage.
Only adjust it if absolutel necessary.
!st you remove the hose at the rear of the plenum chamber to IAC ( stepper motor housing.
It helps it you have to pieces of hose with one blocked off end on each to the re fit to the plenum chamber and the other to the stepper motor housing.
Next start the engine, it will want to stall, try light throttle to keep it running. Once it runs by itself, then use the Allen key to turn the adjustment screw till you get the base idle to specs.
When it is set , stop engine refit the original hose back.
Posted: Fri May 14, 2004 8:52 am
by bazzle
Thanks fellaa. Base idle easy.
Ill prob need a CO meter to check mixture on Airflow meter.
Bazzle
Posted: Sat May 15, 2004 8:59 pm
by mickrangie
Hey,
with the base Idle the easy way is to clamp the the 3/4" hose at the rear of the motor.... set it so it idles at about 500 rpm then relase the hose
you can factory reset yr airflow meter by using an ohm meter on 1st and last pins factory spec is 100ohm...
IMHO if you are going to play with the airflow meter test the ohm's before you start so you know where to put it back to if you fark it up..... and if the ohms don't change it means the ait flow meter is farked.... and you can buy mine
hth
Mick