Porsche Enthusiasts Club Forum

Hi, my S2 is ticking over at about 1400 rpm all the time since the engine was rebuilt
I have tried spraying all of the vac pipes but makes no difference to the revs
Today i tried clamping the hose from the inlet boot to the isv,this made the revs drop right down.
I have had the isv off before and noticed when not connected it sits not completely shut.
I have a spare isv that also looks like this.

Should the isv be completely closed when no power is going to it?

Also have you any other suggestions what it may be if it is not the isv?

This is all that is keeping me off the road.
thanks,Tim

Hi Tim

I cleaned my ICV by taking it off completely and soaking it in carb cleaner, as my car s2 had erratic idle issues after a few starts during the same day.

I did note at the time that the valve was not completely closed with no power on it.

The clean did cure the idle issue though.

Mark

I would still be tempted to say a vacuum hose of sorts. The offending article can be awkward to find though!

Failing that, I know that on the turbo cars there is a master method of resetting the throttle (assuming everything is working fine). I guess you could give that a go if it is applicable to the S2.

This is an unlikely culprit but have you checked the resistance of your temperature sensor. Is your idle always at 1400rpm even with the engine being started from cold?

If you get massively stuck I would be willing to have a look at it (2 heads are hopefully better than one!) for a few beers .

Thankyou for the replies.
I have allready cleaned the isv.
I think the idle might be slightly higher when cold,but i will re-check
I have not checked the temp sensor resistance,do you know what it should be?
Im sure i have a used spare one though.

Thanks again

I've found the values on Clarks,will test when i get a chance cheers

you could try my isv or other bits, if you don't mind driving to Leighton Buzzard.

Hopefully solved......
I couldnt hear the TPS clicking when throttle released so i adjusted it to click
I then tested the resistances to find it does not work on the idle setting(ok on full throttle)
Luckily i have a spare,which i have fitted.
Started up from cold and it sits just above 1000rpm.
I need to move some stuff before i can get it out of the garage and warm it up.(stinks the house out otherwise)

Fingers crossed

Thanks again for your assistance,Tim

I took my old TPS apart to have a look.
The micro switch is working but the connection between switch and the plug pins is faulty.

The micro-switch is made in England! (Bosch part)