After I start the engine idles at 1k until I touch the brakes then it goes down to 600. I have not done any mods. Is this normal?

 

Yup that's normal in cold weather

 

do a search for high idle mod. Many of us put the high idle on a switch to purposely make it idle high.

 

Hey caprang can u help me I did the high idle mod and it doesn't work

Connected yellow w/green tracer to brown with grey tracer together and nothin even with in P and e-brake on

 

What's the purpose of the high idle mod when it high idles normally in cold weather?

 

Well it only does it when the oil is below a certain temp after that any idle and ur wet stacking

 

Just pop off the plastic cover under the steering wheel, find the green/yellow wire in the large bundle of wires just above the Ebrake (they are bundled together and all have a black heat shrink looking end on them) then right above that bundle you'll see another group of 4 wires, I forgot the colors, but there is a solid brown one in that group (the brown one is for upfitter switch #4). Just make a jumper wire about 3 or 4 inches long and connect the green/yellow to the brown wire.

Make sure you use the yellow/green wire (SEIC) and not the purple/brown wire (BCP). I tried it with the BCP first but only got 900 rpms, switched to the SEIC wire and its dead on 1,200 rpms every time.

Also be aware that it only works with the switch on, trans in park, and parking brake engaged. I basically leave my upfitter switch on all the time. When I need the high idle I set the parking brake and it jumps immediately. I also use a remote starter so in the winter I am sure to set the brake before getting out of the truck so when I remote start it the next morning the high idle works.

 

Rudiak,

"The diesel engine contains a unique, Cold Weather – Idle up feature,calibration strategy within the Powertrain Control Module
(PCM). Under the appropriate conditions, the strategy will automatically elevate the engine idle speed after 130 seconds of idling
in cold ambient temperatures. For this feature to be activated the
truck must be in P (Park) (for automatic transmission), in neutral (for
manual transmission) with the park brake applied and engine oil
temperature below 158°F (70°C). This strategy raises the rpm to a level that reduces the potential to produce Coking or Wet Stacking,
which is common to all diesel engines when idling for extended
periods during cold ambient temperatures."
From the FMC "Diesel Supplement Manual"

 

I just completed the high idle mod. Only took about ten minutes and it works great. Wish I would have known about this sooner.

 

What exactly is wet stacking?

When you are talking about the high idle mod and it being linked to upfitter switch #4, are those the up-down switches below the CD player area?

Thank you

__________________
2008 F-350 6.4L PSD SCLB SRW

 

Upfitter switchs are the up/down switches.

Wet stacking is where you do excessive idle (600rpm) and you basically wash the cylinders with unburnt fuel. You take away the lubrication and then all this unburnt stuff goes out the exhaust.

Especially not good in these newer emissions motors.

 

Is this type of high idle the same as an increasing idle? I have noticed while in P and the parking brake not on, the idle will go from 750 to around 1000-1100. If I bump the accelerator the idle will come back down. Any thoughts if it is not the same as described above?

 

SandR,

What he are experiencing is the cold weather stragey. PCM sees that the motor is cold, in park and is just sitting there. It then increases the RPM's to maintain some sort of heat thereby reducing the wear of the internal parts from a cold motor and cold oil.

The high idle increases the RPMs in the same manner, just user controlled.