So I haven't driven my truck since Wednesday. No big deal, I go out this morning to start it, ambient temps are about 30*F. I cycle the grids twice, but the second time I don't hear my raptor run... first time I did. So I cycle the key again and hear the raptor again. Alright that was strange. So I crank it over, spins maybe 6 times, then fires up and revs right to 1k RPM. I freak out and look to see that my foot is NOT on the throttle. I go inside for a minute, come out, and hit the brakes and the idle comes down like it was already doing cold weather fast idle. Driving it just to my parents house where I am now, it behaved fine. Nothing strange, fuel pressure good, truck is near stock. Any ideas what may have caused this? NO codes. Thanks

-J

 

The cold temp is what caused it. Normally that occurs when the ambient temp is below ~15*F, but I have seen it as high as 23*F.

Below ~32*F after 2 minutes the rpms will climb to 1K
Below ~15*F the rpms will instantly climb to 1K.

From the 2005 Owners Manual

NOTE:
• If ambient temperatures are low and the coolant
temperature is below 200°F (93°C), the engine idle
speed will slowly increase to 1000 RPM after 2 minutes
of idle, if the following conditions are met:
• foot is off brake pedal and throttle pedal
• automatic transmission is in Park (P)
• vehicle speed is zero
• Applying the throttle will cancel fast idle
• If the engine is equipped with an aftermarket exhaust
brake (manual transmissions only), operating the exhaust
brake at idle will greatly improve warm up rate
and will help keep the engine close to operating
temperature during extended idle.

As for the Raptor the cycle time is sometime short on the second grid heater cycle. I don't do the second cycle often, even in sub zero it fires instantly with one cycle, and the motor spins faster as the grids haven't drained the batteries for the extra cycle.

Also, fill out your sig so we know what your driving.

 

When it gets that cold out mine will automatically shoot up to 1000rpms as soon as it starts. Sounds normal to me....

 

Yup normal operation.

I never double cycle the grid heaters. No need to second guess the guys who designed the engine and ecm strategy. One cycle has worked for me for 154K miles even when visiting in north PA in the winter.

 

I had no idea it was normal. That's a load off my mind. Noted also on the second cycle, bad habit from the 2nd gen days. I should have a sig, guess I was mistaken. Thanks for all the input.

-J