idling problems when warm

[chillipepper]

just had my evo 4 RS serviced but i am still having problems with the revs dropping when idling especially after driving it on a motorway (at speeds above a 100) (not that i ever do that of course)!!! it has new HKS iridium plugs fitted which has made a slight improvement. . . .

Any ideas would be appreciated

 

[MR.LANCER]

does the problem occur also when cold or only at warm '

Idle air control valve located under throttle body unit.
this would also occur when cold too.

 

[chillipepper]

no ticks over perfectly cold, just when you give it some then say idle at a junction????

 

[ElDopesta]

Check all of your vacuum pipes buddy. What dump valve do you have at the moment???
It may well be leaking.

El

 

[sponners]

no ticks over perfectly cold, just when you give it some then say idle at a junction????

are you running a vta dump valve? the above quote sounds like common symptoms of running a vta.

 

[ElDopesta]

are you running a vta dump valve? the above quote sounds like common symptoms of running a vta.

That is exactly what I think too.

El

 

[chillipepper]

dump valve is completely standard

silly question but what is vta????

 

[sponners]

idle control valve may need cleaning? worth a try

leaks in boost pipework anywhere?

 

[chillipepper]

PROBLEM SORTED!!!!

bought a blitz dump valve off a mate originally made for a skyline, modified it to fit the evo
and JOB DONE, idles bang on 900!!!!

Cheers for the help peeps!!!!

 

[steveo]

Hi Mate,

I've just noticed that i am experiencing the very same thing . How could i check which part is faulty? Does anyone have pics or methods to test??

Thanks
Steve

 

[chillipepper]

If you have any mates with a dump valve that will fit you could borrow it to see if it sorts it, apparently it is common for them to cause this problem

 

[steveo]

Would a DV off of an 2005 Impreza fit??

 

[ElDopesta]

There is quite a simple test to determine if there is a leak in your dump valve:

Take it off and press the piston from the underside, once it is fully pressed, cover/hold the vacuum inlet on the top with pressure (the small nipple that the vacuum pipe goes into). If the piston shoots back down, then there is a leak. If the valve is good then it will shoot down only when you let go of the nipple.

Give it a try.

It is also worth remembering that whenever there is and idle/hunting issue, it is wise to check all pipes/connections. I have said it time and time again for a reason.

El