Archived Subzero - starts, but little or no power, and no wait to start light

[TomW]

2006 Dodge 2500 Cummins in Minnesota. The truck is parked outside, and the block heater is plugged in when parked.

Here's a brief history up to this point.

A couple weeks ago, the wait to start light quit working. Since I plug the block heater in at night, and it started normally, I decided to wait for warmer weather to chase it down. No codes at this point. One morning I had the engine lose power and throw a code, about a mile from the house. I limped back home at low speed, and added a winter fuel treatment. I let the truck idle for 20 minutes for the treatment to mix with the fuel. The next day I got 12 miles farther before having the same problem again. Added a second winterizing agent, and let it idle for 30 minutes. Yesterday was even colder, and I didn't make it out of the neighborhood.

I have a Scan Gauge and I added the codes to read the high pressure fuel pressure. The pressure drops to 1-3k psi when the truck loses power, and throws a code. Normal pressure is around 7k at idle to 28k at full throttle. I'm still having fuel gelling issues, but I no longer think it's just the fuel.

There is no code that the wait to start light is burned out. The only code is low fuel pressure. If I leave the truck unplugged and let it cool down, I no longer hear the relay for the grid heater.

I did some research and dug thru the parts diagrams, and I have a few questions.

1. Is there a way to test if the factory fuel heater and thermostat in the fuel bowl is working?

2. One reference I found stated that if the intake air temperature sensor wasn't working, the wait to start light and grid heater won't function. Is that accurate?

It's 1 degree above zero and breezy outside, so the fewest/easiest things to check and/or replace is really appreciated!

Thanks for the help!

 

[Loren]

TomW,

Sorry, I can't help you with troubleshooting the fuel heater or the thermostat. I have a few thoughts though.

I don't think that the low power condition and the wait-to-start light failure are related. I'm sure you know that if you plug the truck in the grid heaters and the wait-to-start light will not operate. The engine should already be warm enough to start immediately. I don't remember trying this at sub-zero temperatures, but every time I've plugged my truck in it's started right away.

I agree that the low power condition is almost certainly from fuel gelling. I've never used additives in my fuel so I can't recommend any. When I did have this problem (-15 degrees) my tank was only about half full. I drove to a popular truck stop (that pumps a lot of diesel) and topped off the tank with good fuel. That solved my problem. If you have room in your tank and can get to a truck stop it may help you too.

Good luck,
-- Loren

 

[JR]

If your adding a basic anti gel additive it won't help your situation once the fuel is gelled. It is a preventative but once the fuel has turned you Need to buy something like the power service 911. Its a hotter formula designed to break up the wax parrafin in gelled fuel. You should also change your fuel filters but if you don't have any and need to be back up and running at a minimum take them inside to some heat to thaw them out and reinstall.

 

[ofelas]

My summer fuel (full tank) filled up in August 2017 gelled up on me during a hard 3 day freeze of -41, haven't used the vehicle since August LOL.

Added a quart of Diesel 911 to the tank & let it sit overnight.

Set the Webasto timer to 120 minutes with its exhaust pointed at the filter canister, and it fired up. Ran the old girl on the highway till almost empty, and refilled with fresh winter blend diesel + a dose of Amsoil all weather antigel additive.

So - you could try the 911 red bottle + point an electric heater at the fuel filter for an hour or two, dont crank/run the truck out of fuel before you thaw out the filter, or you'll be bleeding your fuel system to start up after the system is thawed.

Good luck!

 

[AH64ID]

Use the scan gauge to look at engine coolant temp and intake air temp. They should be similar on a col motor. With the block heater the coolant should be a little warmer than the intake.

If the intake is above 66° you won’t see a WTS light, on stock tuning.

You don’t need to leave it plugged in all the time. 90 minutes gets you 90% of overnight tempsvat a fraction of the cost. Any old 15a outdoor timer should work.


On a side note, the rail pressure sensor shouldn’t read above 26K and the OEM pressure peaks at 23K. Are you programmed?