Wots the fix for a fast idle?

**gmzez** · 21-10-2005, 10:59

I?ve scanned the old posts looking at high idle speed faults.. It seems that a typical fault that the Cos Sierra suffers from is a tick over that fluctuates between 1000 and 2500 rpm. Another fault includes hunting between these revs.

However, I?m unable to locate feedback from these posts after owners have fixed the fault.

1) tickover at a steady 2500rpm
2) Hunting between 1000 and 1500

Anyone out there fixed this problem? Many thanks guys?

**nickmk11** · 21-10-2005, 22:51

check your idle control valve ,they do get shitted up with oil etc ,give it a clean and a bit of thin oil to lub it up

**tarmac terriost** · 22-10-2005, 18:41

like nick said check and clean your idle valve
also check ht leads,spark plugs, dizzy cap ,and rotor arm ,if not electronic
also check breather pipes and vaccum too
make sure air filter is clean too

**gasant** · 23-10-2005, 09:53

hi this may sound a bit silly but have you got the correct plug gap ? as i have found that by having the wrong plug gap my engine would not idle smoothly and slighty hunts.
i didnt think that it would be so crittical but through experimenting with the gaps i have made the engine run more smoothly.
ps. the gaps are different between 2wd & 4wd.
hope this helps.!

**tarmac terriost** · 23-10-2005, 18:41

wots the difference between the 2wd and the 4x4 gap wise

**gasant** · 24-10-2005, 20:24

hi if you are using a 2wd head then plug gap should be .75mm
if you are using a 4wd head then plug gap should be 1.00mm.

this may not sound like it would make much difference but i found out the hard way,through experimenting with the gaps, get it wrong and you get uneven idle.