Bad Idle

[cj_wig 0]

Hey Guys,

Looking for some advice. I bought a VR6 converted Ibiza yesterday that has an idle problem. The engine is a OBD 1 from a 1992 Golf. When it's idling it's reving up a little and then dropping down a little, so it's going between 800-1k. I was told that it's been fitted with a 2.9 TB, so there is something on the top of the engine that isn't plugged in. He said that if you plug it in the car cuts out. IT looks like an idle valve to me, but i don't really know much about these engines.

Any help would be great

Thanks

[russj249 2]

Idle control valve on an OBD1 is just to the right of the throttle body. There's a pipe going in from the plastic inlet to it, and a pipe going to the inlet manifold.

It should be plugged in really otherwise it will hunt. I would try and get a standard throttle body just to test, plug idle valve in and go from there. They are fairly common to play up.

[cj_wig 0]

This is what is uplugged:-

Also i found these around the throttle body:-

I plugged the top one back in, but when the car started it run out straight away :/

[russj249 2]

First pic is idle control valve, which should definitely be plugged in. My guess is he has adjusted the screw on the throttle body to raise the idle that way instead, which is ok when its warm but won't idle from cold.

Second pic is a blanked off vacuum home that should go to a plastic PCV valve, which is missing on yours and has been fitted with a bit of rubber hose instead. Lots of problems on these so google search for vr6 PCV valve and you'll see what its meant to look like.

Third pic isn't an issue as the plastic plug is only for US cars for emissions related stuff.. if you look in the connector you'll see there isn't any pins for it to plug into.

[russj249 2]

Also, there is a bit of loom that has been re-taped up for some reason, this is the loom for the throttle position sensor. Just make sure this is all working. Ideally you could do with putting it on vag-com and check throttle position percentage values.

[cj_wig 0]

so doea that mean i need to fit a PCV? also any idea how i can stop the car cutting out with the idle valve plugged in?

[russj249 2]

Erm, in theory as long as the vacuum is fully blanked off, you should be able to get away with not having a PCV valve, however there will be a blue valve on the left hand side somewhere probably just left loose. This is for fuel tank vapours to be recirculated into the engine.. the ecu will count for this so it needs to be going into the inlet somehow.

Also it may just be a faulty idle control valve. Ideally you need to get it on vag-com and see the values for it.

[filtee 0]

Maybe clean it then plug it in?!

[cj_wig 0]

I'll have a look for that tomorrow, i didn't have a proper look when i took the pictures.

I was thinking that it might be stopping it. Would it work with it being a OBD1? most of the cables i've seen are fore OBD2

[cj_wig 0]

Better picture of the throttle body

There is a blue pipe near the front side of the inlet if that is it

[filtee 0]

Id just try the free fix i mentioned earlier. Take the isv off and clean it with carb cleaner. Theres a how to on this forum. (you need to become a premium member to view it). Once youve cleaned it, ditch the little black filter above it as its not really needed. You can use one of the original pipes to route back to the throttle body. Do all that and then plug the wiring back in and see what its like. May sound a bit long winded but takes no more than half hour and is free. Youll need 3 jubilee clips though.