What does this switch do?

[3vilc]

Hi all,
Just wondering exactly what this switch does or is meant to do..
On a 3.1TD. Looks like a 'check engine' symbol with a coil in the middle (same as glow plug symbol). Presumably it is some form of engine heat or preheat as it only functions under 8deg ambient temp but how exactly does it work?
When on, I can see the manifold pressure drop to a vacuum and back to 0 in a cyclic action. I have seen while under the truck some sort of device in the exhaust pipe controlled by an actuator, is this something to do with it? like the exhaust brake on a heavy vehicle which can also be used to speed engine warmup time.

Thanks,
Clive

[geeves]

the exhaust brake that isnt. This is a fast warm up device. Therory is that it restricts exhaust flow keeping more heat in the engine for faster warm up. Thats all it is Dont know how well it works Ive never used mine.

[mbw13]

I don't own one of these, but I'm pretty sure it's a quick warm up system which closes off a valve on the exhaust or partially closes the valve in order to recirculate warm exhaust and/or makes the engine work harder to warm up quicker. Although I've heard of cases where this valve can stick closed if not been used every now and again causing loss of power and apparently grey smoke. Also this device only works under 5c give or take.

Edit: Just noticed somebody pipped me at the post ;D

[James W]

It also advances the timming slighty, don't drive with this on, it produces a jerky behaviour and is hard on the engine.

[JustinW]

Slightly off topic, but my 3.1 Wizard has one of these buttons but no manual fast idle knob. Has anyone tried retrofitting one? I could really use one when winching and using the compressor.

[geeves]

Shouldnt be hard but youed have to look at a vehical that has it very closly to see how it works I think its conected to the accelerator pedal somehow as theres no second cable under the bonnet

[3vilc]

On my bighorn it is connected to the throttle pedal so I assume a wizzard would be the same. Hard to see exactly how its connected without taking the dash apart tho.

[Harry]

Depends on whether the Wizard has it's own pedal or Isuzu is using up millions of left over MU and Bighorn ones.
Harry.

[wizbru]

My wizard has a cable connected to the pedal - Just about wrecked it first time I pulled the dash apart.

[Harry]

There should be 2 cables from the pedal.One goes through the firewall to the squirter pump.The other goes up to the knob on the dash.
Harry.

[draganlada]

Since we are talking of cables and pedals,I have a question: does your accelerator pedal have a free play ? Actualy,my accelerator cable is about 10 mm to long at accelerator pedal side so pedal has a free travel.Tomorow I'm going to fit some kind of spacer in there to eliminate free travel what should resoult with much beter pedal response ( I guess).