Here is my experience starting both of my trucks in the North East during this onset of the dreaded "Polar Vortex".
I have two CUCV's, an '84 (built late '83) M1009 and an '85 (built very early '85) M1008A1. Both have:
- New Air filters (Fram, wicked cheap at RockAuto)
- New Fuel Filters (stock Stanadyne rectangular military issue)
- Rebuilt fuel injector's using brand new Bosch nozzles (Badger Diesel)
- New plastic fuel tanks (only because I know the steel tanks will eventually leak, so changed them while I could, 31 gallon on the M1009)
- New fuel sending units (Spectra Premium, see fuel tanks above)
- Lift pumps that came on the trucks when I got them, look original but no real way to know (will be changing when it warms up, plus adding electric with prefilter when it's not so cold my fingers hurt in less than a minute holding a wrench)
- All wiring connections cleaned up and greased, especially the battery terminals and starter cables
- 24V starter
- Rebuilt Injection Pump (about 1 year old from Badger Diesel M1008A1, estimating no more than 2 years old on M1009 but came on truck so no way to know for certain)
- Fully functioning stock Glow Plug system - resistor bypass
- Sixteen good/new and tested AC60g's (eight per truck of course)
- No fuel additives (but they have both been filled up with Winter blend fuel available at local pumps since Fall)
- Doghead relay upgrade (Thanks again Eric!)
- 6TL's in the M1009 and Optima Red Tops M1008A1, both date codes in 2009 and same batteries from when I received the trucks.
- Compression tested and all 16 cylinders well within specifications.
- Rotella T6 synthetic motor oil.
Unless I am missing something (apologies if I am) everything else is as it was when I received the trucks relative to fuel/ignition and electrical starting systems.
Now for the actual experience. This is for both trucks, started daily during this latest onslaught of Global Warming. Coldest temps seen here (when the Dreaded Vortex has been closest to us) were about -10F overnight. Average has been about 5-6F.
Followed starting procedures indicated on visor (as I always do). GP's energized immediately on key turn (relay clicks nice and loud) and Wait Light lit for about 18 seconds. Foot to floor and turn the key. Fired up in under 3 seconds and stabilized in less than 5. Afterglow automatically kicks off at about 40 seconds. NO afterglow "pulsing", just a steady on. The truck's were ready to rock and roll in just over 1 minute.
This has been my experience. Your mileage WILL vary!
I will admit I am confused when people say they cycle the GP's more than once. I see no indication that the GP's are de-energized when the wait light goes out, at least not initially. So, if you feel you need extra heat for some reason why not just wait longer after the wait light goes out? Plus, you won't be letting the plugs cool down during the reactivation. I will defer to Antennaclimber or others more familiar with the stock GP controller to correct me if I am mistaken.
My other point on this practice is that good working GP's will reach maximum temp fairly quickly. I am not certain I understand what the extra time (beyond the already extended 18 seconds programmed into the controller for cold starts) is providing. The purpose of the GP's, as I understand it, is to provide a source of ignition heat when the engine may be too cold to ignite the fuel oil by compression alone, especially on the relatively slow RPM's the starter provides. They do this by glowing to white hot while being in the path of the injector spray. These tiny plugs aren't radiating much heat into the massive (by comparison) steel of the heads. They provide a source of ignition heat directly to the fuel spray.
One last side effect of this practice. By running the GP's longer, you are removing charge from your batteries, a charge you may prefer to go into the starter.
If my understanding is correct, if you have to cycle your GP's more than once you likely have at least one issue elsewhere that is preventing your truck from reliably starting.
I look forward to any corrections to my understanding.