scottydouk

iTrader: (3)

as title really, come to junction dip clutch and engine speed hunts and sometimes cuts out. once stationary after about 10 seconds idles as should do and smooth.
no fault codes logged and no air leaks.
is this more likely to be a idle speed valve fault?
cheers

adzer

iTrader: (13)

i had this problem

it just went away lol.

fygtbug

do you have a vent to air dump valve by any chance? if so its the spring thats not stiff enough (problem with cheap ones) and its leaking metered air under vacuum causes idle hunt and possible stall but does even out once ecu mates up with Idle control valve

that would be my guess....

scottydouk

iTrader: (3)

yeh just a vent to atmosphere dump valve. if i just disconnect vac pipe to it and try will this be ok? obvisouly not booting it.

fygtbug

yes you can try that, but do not boost it, just drive around to get it warm as the idle control valve will stop most of the problem on startup as the engine warms up, then just come to a stop and see what it does. should idle fine if it is the dump valve.

if its this and its one you can unscrew or take out screws to get to the spring, you can get stiffer springs or pack them with washers to get the right stiffness to hold it closed under light vacuum which is when your having the issue.... dont pack it too tight still needs to vent with ease shouldn't flutter as you let off boost

scottydouk

iTrader: (3)

disconnected vac pipe to dump valve and fault cured! spot on 'fygtbug' nice one! much appreciated! have adjusted tension on spring and is all good!