ZS 180 High Idle Revs and running rough

[s1nn0n]

Hi,
I had a knocking noise coming from the inlet manifold, so I removed the manifold and stripped out the butterfly valves in the manifold, resealed the manifold and refitted. I am pretty sure the manifold is air tight. Now I have a problem in which I didn't have before(but the knocking noise has now gone :cool2:), the car will idle at about 2krpm, and drives quite rough, the car still seems to pull and rev when you don't have your foot on the accelerator. I have made sure that the throttle cable is routed correctly.

One thing I have done, is remove the valve(flap) out from the top left of the manifold where the other VIS motor is situated. Could this cause the problem? What exactly does this thing do? Do the cars normally run ok with the VIS valves disconnected?

Thanks.

[s1nn0n]

Anyone any ideas please? The revs will increase even further when the car is moving when the clutch isn't engaged or not in gear! This didn't happen at all before the inlet mod, so it has to be something related.

[Dan1971]

You need to speak to "Kitch". He's done the same thing and has the same issues on tickover I think.

As far as I know, he's the only guy running the KV6 without the valves, which accounts for the lack of responses I imagine mate ....

[thered180]

My vis valves are currently unplugged, and i have no running issues at all. However I have not modified my manifold in any way.

[grimmy]

Sounds to me like there is air being drawn in through the manifold.I would check that for leaks

[petet16]

Sounds to me like there is air being drawn in through the manifold.I would check that for leaks

I'd go with this as well, the high idle has all the symptoms of an air leak.

[Skillen]

Seen a few posts on .org that mention using butane around the edges to check for leaks.
Dunno if this is sound advice but I guess it would work.

[redzed]

Pretty sure this happened to kitch and he did something with blue tak on the idle valve I think, might have completely wrong end of the stick tho

[Nor]

When you put the VIS motors back in, did they definitely have the rubber gaskets on?

One other time I had this, it was a faulty potentiometer (iirc).

[Dan1971]

Pretty sure this happened to kitch and he did something with blue tak on the idle valve I think, might have completely wrong end of the stick tho

There was something in there .....

[s1nn0n]

When you put the VIS motors back in, did they definitely have the rubber gaskets on?

One other time I had this, it was a faulty potentiometer (iirc).

The balance valve vis did not have a gasket on it when I removed it. Maybe this is where its sucking the air from, the power valve did and does have the gasket on.

[s1nn0n]

Just been out and cleaned all the sensors around the throttle body, the car also 'hunts' for revs around the 2krpm mark, but sometimes strangely it will idly somewhat normally at 1100rpm. There is a sensor, right on top of the inlet manifold just before the throttle body, that when unplugged the revs drop and it stops hunting for revs, but the engine is nearly stalling with it unplugged.

[petet16]

it's the map sensor.

[s1nn0n]

Bought a new manifold with new vis motors, hope that will cure it!

[s1nn0n]

New inlet manifold cured it!

[M17TT180]

Handy to know, how much out of intrest?

[s1nn0n]

Handy to know, how much out of intrest?

£130 second hand with VIS motors from a 48k mile car.

[James Raby]

you only needed the gaskets that sit inside the motors

gutting