[Scrufdog]

Needed to run out yesterday when it was 21 degrees F out, snow on the ground. Went out to truck fired her up, easily as always, let her idle for a minute to settle down then hit the high idle switch. Upon high idle the engine would make a stumble every 6 seconds or so, kinda like a quick cut off that lasted less than half a second. Since I was standing outside, while snowing, in bare feet and shorts, I left it and went inside. Came out 5 minutes later and she was purrin pretty at 1070RPM (high idle). Figured it might just be a cold fuel thing.

I currently use just over 6oz of Power Service and 2oz of 2-cycle oil. Already decided to go 8/8 starting on the next fillup.

Any ideas?

 

[Turbine Doc]

Maybe a cold advance anomally, hunting timing a little until she warmed up

 

[gmctd]

Fast idle is for PTO and HO alternator and hydraulic winch and other engine-driven loads at normal operating temperature - not for fast warmup at cold-start.

Erratic operation may be expected at ECT's below ~115 deg, where PCM starts throttling back from normal cold-advance\fast-idle

 

[Scrufdog]

so you dont think the high idle helps warm up?

 

[gmctd]

Sure it does, but that's not the function of switched High-idle option - you should expect some erratic operation as PCM tries to compensate for cold-start with normal parameters for cold-advance and fast-idle

 

[Scrufdog]

mmk. It does serve its purpose for Alt. duty, when I need a full 60 amps for my inverter, its great.

So cold diesel + high idle = possible oddball operation. Sounds good to me, just gives my truck some 'cold character'