White smoke at startup 300hp 1992

[doghouse]

Is it normal to have quite a bit of white smoke comming out of exhust at startup?
It discontinues after about five minutes of running.
Thanks
Scotty

[doghouse]

Is it normal to have quite a bit of white smoke comming out of exhust at startup?
It discontinues after about five minutes of running.
Thanks
Scotty

[RustyJC]

It is in cold weather if you don't wait for the intake grid heaters to run through a full cycle. It's unburned fuel due to cold intake air.

Rusty

[Mike Canter]

When that happens on our diesel truck it means there is water in the fuel separator and it needs to be drained. Unburned diesel fuel is dark gray to black in color. Burned oil is blue in color.

[RustyJC]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mike Canter:
When that happens on our diesel truck it means there is water in the fuel separator and it needs to be drained. Unburned diesel fuel is dark gray to black in color. Burned oil is blue in color. </div></BLOCKQUOTE>
Partially burned fuel is dark grey to black in color - the soot (black) that pours out when the fuel comes in ahead of the turbo boost is generated when fuel is burned with insufficient oxygen present. Fuel that is injected with insufficient air temperature to initiate good combustion will generate a white "mist" with a heavy diesel fuel smell. Low fuel pressure (a plugged fuel filter or a bad lift pump) can cause this as well.


Rusty

[Mike Canter]

Rusty I understand what you are talking about but he said on startup and there would be little to no turbo boost. A plugged fuel filter or a bad lift pump would have unburned fuel all the time and not go away.

[doghouse]

Thanks Rusty
I am still trying to locate the grid intake heater to see if it is working. Do you know where I can find a picture of one? Is it located before the turbo?

[Mike Canter]

Also, I don't think a 1992 Cummins has a intake grid heater.

[doghouse]

Thanks Mike

Right you are, the 1992 did not come with a grid heater, at least not mine. I did find the plug in block heater. If I plug it in 1 hour prior to starting, she will start on first crank with very little smoke. I don't see a "wait to start" light on my dash, but I do have a mystery switch (rectangle with zig-zag line in center) located on dash pod. Could this be block heater control?

Thanks

Scotty

[Mike Canter]

Normally block heaters are just a plug into 110V with no switch. Does the zig zag switch light up when turned on?

Have you opened up the water drains on both the fuel filters yet. You should have one small one on the top passenger side of the block on the injector pump side which may or may not have a water drain in the bottom and you should have another large fuel filter with a water separator on the botton that has a drain on it. This maybe located in a compartment that is accessed from outside the mh

[doghouse]

The block heater is a 110V plug with no switch. It leads to the block, but two other wires also lead to ports in the block on the same side of the engine. I am trying to figure them out. The zig-zag switch does not light up when turned on. Maybe a blub. I changed the large water/fuel separator and drained the smaller one under the pump last night

[Mike Canter]

Scotty, is that switch with the zig zag marking a spring loaded push and hold or is it a rocker switch with two positions?

[doghouse]

Rocker switch with two positions

[Mike Canter]

Do you think that there is a possibility that is a outside rearview mirror heater switch? Do you have one labeled as such?