black smoke

[Hars]

I had the exact same thing happen with my engine and this is what I found. In the air intake piping, where the EGR pipe meets the turbo air, just before the intake manifold, there is a flap-type valve (God knows why it it there) that can completely block the air from the turbo. It is operated by a 2" vacuum solenoid immediately in front of it. When your engine starts going up and down at idle check and see if this valve is cycling open/closed. If so, there are two vacuum lines going to the actuator. Disconnecting the lower vacuum line should keep the valve open all the time. I see no reason why you would want to block air from your turbo so I just plugged the vacuum hose and left it off. Haven't had a problem since.

Good Luck,

Paul
Just saw this on another thread,may be simillar?

My Surf has two flaps in the position you describe. A big one operated by the throttle cable and a smaller one operated by the vacuum. The smaller one controls intake air over the heater during idling. Does yours also have two ? If not, then this one valve operated by vacuum which controls all air could be the culprit ???

[brian gillies]

My Surf has two flaps in the position you describe. A big one operated by the throttle cable and a smaller one operated by the vacuum. The smaller one controls intake air over the heater during idling. Does yours also have two ? If not, then this one valve operated by vacuum which controls all air could be the culprit ???

There is also 2 flaps in the throttle body 1 controled by vacuum.
I disconected the bottom pipe but it made no difference. I have been told it is valve clearence that is the problem . I have a mechanic coming on teusday to replace the shims.

[brian gillies]

There is also 2 flaps in the throttle body 1 controled by vacuum.
I disconected the bottom pipe but it made no difference. I have been told it is valve clearence that is the problem . I have a mechanic coming on teusday to replace the shims.

Just to let you all know the surf is finally fixed. The problem was valve clearance believe it or not. The mechanic says the valves were cut to short and the shim were to big. When the engine heated up under load the valves were not shutting right. So thank you very much everone for all your help.

Many Thank

Brian

[BUSHWHACKER]

Hurrah! I can sleep now!