APD

On cold mornings (<20*F) my truck will run very rough and wont idle at first start up.

My solution is this: if it idles rough, I take a heat gun and warm up the filter for a minute. I then open the filter drain. Nothing comes out. I then hit the fuel prime lever once or twice, and a bit of liquid shoots out. I close the drain, start her up, and all is good. It will idle and run smooth. One time I had to do this twice.

Here is the catch:
Once the truck is warmed up, the problem disappears and I can drive all day. And the problem only occurs on really cold days.
The filter is brand new, Fuel has been treated with "diesel 911". I fueled up from the same gas station in my VW diesel and my Kubota diesel tractor. Neither of the other two engines have this problem.


All I can think of is that there is water in the tank, getting in from the filler neck or something. Is the cummins super-sensitive to gelled fuel? Any ideas?

Geico266

Do you add any Power Service (or similar) to your fuel to prevent gelling?

If the heat gun helps you must have restriction at the fuel filter. Have you changed it lately?

If you had a fuel pressure guage to monitor fuel pressure after the filter you would know for sure.

chuxtruk

Wouldn't it be easier just to plug the truck in??? If you don't want to pay for the constant use of 750 watts/6.5 amps of power, put it on a timer for 4 hours which will warm it up fine and watch your problems go away....
But a heat gun??? Anyways, soon as it's running there's a 12 volt warmer on the fuel filter housing anyway that's supposed to help keep the fuel from gelling. These trucks ALL came with a plug in block heater as original equipment and something like this is EXACTLY why you plug it in. If it's not there or is not working, a new cord and heater will run about $75 from the dealer and is cheaper yet should you have the good fortune to live near a Cummins dealer. They're even cheaper on Ebay but they're not genuine Cummins parts there either but I have seen them there too. Fwiw. Good luck
Chuck

APD

A previous owner removed the block heater. Why? I have no idea.

MJDiesel

Maybe try a Case IH tractor dealer if there is one close to you. Some of the older tractors had a 5.9. It might be cheaper yet, but then again, maybe not. Just a suggestion.

G1625S

Just to clarify, if it's a warm morning, it'll start right up, even if it's been sitting overnight?

rebal

may be the KSB not woking?

wannadiesel

When it's cold (below 40 degrees or so), unplug the fuel heater and check for continuity. I don't know the exact spec, but it should be somewhere between 10 and 50 ohms.

You should have 12 volts across the plug with the key on, no matter what the temp is. The temp switch is built into the heater.

APD

Yes, on a warm morning it starts and runs fine.

I originally suspected the KSB also, but after heating up the fuel filter, it seems to run fine. I dont know, maybe my fuel filter heating procedure is a red herring and not really doing anything?

When I open the filter drain plug nothing immediately comes out, I push the primer lever once to squirt stuff out.

My VW has a water separator/drain at the tank and the filter, I wish the dodge did.

wannadiesel

Could very well be a bad lift pump. The VE will pull fuel through the lift pump as long as it doesn't lose prime. Check the pressure, or just throw a new one at it for grins.

bgilbert

Fuel heater plugged in?