Cougar,

Pull your iat sensor out, only takes a couple minutes, and have a look at it. It's probably dirty. Spray it with a non residue contact cleaner, pop it back in, and see what it does.

Dirty iat sensors are a common problem on exhaust brake equipped trucks. They can play havoc with everything from cold starts and high idle, to fuel economy.

 

I have a new one to put in along with a grid heater and relays.

 

Got them all swapped out. That IAT was a pain. It didn't look terribly bad, but when I tested it on the bench it was quite a bit off. Grid heater looked okay, replaced it anyway sense I had a new one. Went over the fuel lines. The clamps on the hose between the tank and the lift pump were a little loose so I tightened them. Cleaned the return line be hind the engine and used a spray developer that leaves behind a white powder to check it for leaks. Nothing showed up after driving it a while. So now it's going to be a wait and see if I made any improvement.

 

Keep the thread posted.

 

I will, but of course it has turned hot again around here so I can't give it a good check out under the same cold weather conditions.

 

Been warm so haven't had a chance to properly check it out. This morning it was 20° and the truck sat sense Wednesday night. Crank-crank and it was running. Shortly after the idle came up. Need a morning that's around 0° to know if that fixed the problem or not.

 

1/3/15 9:30AM AK time. Outside temperature in and around my truck according to my IR thermometer is -4° to -9°. Took a few more cranks, but it started. After about 30 seconds the idle came up and it went into 3 cylinder mode. Boy that sounds weird.
I feel a lot better about it now. So now back to my normal routine, plug at 20°.

 

-15°. Had it plugged in for 2 hours. Cranked over slowly, but still started. I need to put some synthetic oil in it and up the timer to 4 hours. Thinking of adding an oil pan heater.

 

A circulating block heater works well, battery blankets, a oil pan heater i have seen them go south and cook the oil you would be better off useing a pan blanket and even a belly tarp ?

 

I've used aircraft pan heaters with excellent results in the past. Never heard of a belly tarp. I have used a quilt over the hood, but that only works when it's dry. I need some kind of shelter to block the wind at least.

 

You run a heavy tarp from the rad back to the transmission to keep the heat in, use to do that when it was passed -40

 

Seriously?..... -40? No thank you.

 

I've never belly tarped the 01. Furthest I have gone is canvas over the front bumper holes, starting at the rad support, and wrapping around, tied off at the sway bar. That, coupled with a clip in winter front, does the job nicely. It's amazing how much air those bumper holes let by.

 

ha ha -40, just like the original title of this post STRANGE BEHAVIOR.

at this Temp I would have "Strange Behavior"
well I would not be driving and I would stay home. I have plenty of sick leave.

plug it in for 3-4 hours. and I would look at a oil pan heater. I would think the oil pan heater wouldn't need to be on that long. Do they make oil pan plugs that have a heat element built into? I know of some aftermarket pans that have a element built in as an option.

synthetic would help.
so Im assuming this parks outside in the elements.

even tho i have a smarty I cannot trigger the high idle on demand. but I'm not super cold here. But I'm looking at the High idle set up/Gauge from Moparman.
I know Diesel performance parts. Cummins, Duramax, Powerstroke. now sells them.

 

That's the problem with heating elements in oil pans they relied on a thermostat in witch I have seen to many fail and cook the oil even on low wattage one's