M

mad-mac

New Member

• May 26, 2010

• #1

My K reg RRC 3.9 has started over eevving, have checked for air leaks but nothing apparent, tried turning down base idle, but it just climbs back up to around 2,500, it does settle down after about 10 mins, sometimes hahaha :doh:

 

classic kev

Well-Known Member

• May 27, 2010

• #2

Try cleaning your stepper motor.

 

M

mad-mac

New Member

• May 27, 2010

• #3

thanks, have tried cleaning stepper motor but still the same, what exactly does the stepper motor do?

Rob

 

classic kev

Well-Known Member

• May 28, 2010

• #4

The stepper motor is perhaps more correctly known as the idle air bypass valve (aka idle stabilisation valve) what it does is alter the amount of air that bypasses the throttle disc when it is closed. The ecu winds the valve in or out to achieve a stable idle speed of 725RPM +/- 25RPM.

If you remove the stepper motor and fire up the engine it will run at about 2500rpm as air rushes in through the hole it sits in. Although you say you have cleaned the stepper are you sure it is actually working?

 

jai_landrover

Well-Known Member

• May 28, 2010

• #5

cold start valve or idle control valve back of the engine has a couple of wires going to it stuck valve try remove and try and free it if not replace common problem

 

fett

Well-Known Member

• May 29, 2010

• #6

Could also be the AFM , I am having to have a play with mine today if it stops raining because of a similar problem although not at idle.

 

M

mad-mac

New Member

• May 29, 2010

• #7

thanks everyone, will get to play with it in the morning

 

vougese39

Well-Known Member

• May 30, 2010

• #8

get the ecu fault read will help rather than just guessing how did you set the base idle? coolant temp sensor failed dodgy connection poor earth but all gueses