Cold Weather Starting

[slk]

Ok guys my M37 is very hard to start in the winter here in MN. Any suggestions? When it is around 50* it will start, but not much below that. I can't believe that the government would accept a vehicle in its motor pool that would not start in cold weather. I have been asking around to see if one of those magnetic oil pan heaters would work, and most say they will not. I was thinking of cutting the lower radiator hose and installing an inline heater that could be plugged in. Was there some sort of official part made for this? Any ideas would be greatly appreciated.

Steve

[Elwood]

An "Arctic Powerplant Kit" (http://www.midwestmilitary.net/midwestm ... 37p12.html) was available to pre-heat the engine, but that seems a bit extreme, even for MN. Unless you live in International Falls?

There was also an engine primer, factory installed on the early trucks, and available as an add-on kit for later trucks, but that kit shouldn't be necessary at 50degF. See: http://www.g741.org/PHPBB/viewtopic.php ... primer+kit

Something else is wrong, because your truck should start at temperatures below 50degF without difficulty. Is the choke functional? Does your truck have the stock Carter ETW-1 carburetor, or something else? There are more questions that should be asked and answered before applying a band-aid such as a coolant or oil pan heater.

[NAM VET]

when I got my truck out of Nebraska, since the prior owner would start and drive it below Zero, he put in a coolant heater. In theory, you connect it so the inlet to the heater is low, the outlet is higher, so it self-pumps. Mine doesn't have much of a high-low gradient, but it does seem to warm up the upper block to HOT. I am not sure i will hook it up when I put my motor back in, being in SC. Let me try to post a picture. But like the above answers, there must be something wrong with your choke linkage.
I was bolted to the fender splash panel. The inlet was via an L pipe thread bracket at the rear of the block.
[URL=http://s663.photobucket.com/user/h ... .jpg[/img][/url]

[Elwood]

When I bought my M37 (ex rural fire dept.), it too had a 120v coolant heater. Like yours NAMVET, it was plumbed into the heater outlet port on the back right top corner of the cylinder head. The return was plumbed into the drain port on the lower left side of the cylinder block, however, not into the radiator return pipe as on yours. Not that it mattered much, as the thing was completely plugged with scale.

When my engine goes back in the frame, it will have a coolant filter (http://www.g741.org/PHPBB/viewtopic.php ... ant+filter), but the coolant heater has already gone in the trash.

[Marmalute]

Hey Steve,
As others have implied, something basic is wrong. Have you done a compression and leak down test on engine recently?
I think I would start there. If that was a ok I'd go to ignition settings (plug and point gap) and then go to fuel system checks.
Good luck and let us know what you find.

[just me]

Mine will start at 35 with no problem at all if you don't flood it. If you flood it, you are done for that day.
My procedure.
Switch on
No choke
Crank it
Hit the skinny pedal once or twice if it doesn't fire.
It will fire and stall.
Now I crank again and pull the choke out slowly until it fires.
Immediately push the choke most of the way in.
After it has idled a minute or so, it will be able to take some throttle.
Using the hand throttle I idle it up so it charges the battery and warms the engine.
Open the choke as sound and feel dictates.

This is on an old worn out engine. I expect a fresh build with good compression will be easier.

[DJ]

I can start mine @ below freezing,(Northern wi).

Shift to neutral
Push clutch in
Pull choke out
Hit starter
Let run with choke out until motor starts to slow down
Gradually push choke in
Let clutch out slowly to keep from stalling,
gear oil needs to warm up.

Same procedure also starts my M38.

If you want a heater, a frost plug heater works well.
A heater definitely aids in starting .

[Marmalute]

A year or so ago a real beater M37 followed me home. I figured that I would use it for parts on some other projects. Of course like anyone else, I had to get it running and drive it around to see what condition the various systems were in.
The previous owner had installed a civilian carb and wired the choke "open". My starting procedure for this one is to put in neutral and crank engine with ignition "off", then pump accelerator like 6 or 7 times then ingnition "on" and crank while pumping accelerator a little more. Always starts. Today it sits in a couple feet of snow cover in canvas. It hasn't been run in months but this conversation makes me think it might be time to hookup the batteries and see what happens. It is 30 degrees out today.

[slk]

Mine will start at 35 with no problem at all if you don't flood it. If you flood it, you are done for that day.
My procedure.
Switch on
No choke
Crank it
Hit the skinny pedal once or twice if it doesn't fire.
It will fire and stall.
Now I crank again and pull the choke out slowly until it fires.
Immediately push the choke most of the way in.
After it has idled a minute or so, it will be able to take some throttle.
Using the hand throttle I idle it up so it charges the battery and warms the engine.
Open the choke as sound and feel dictates.

This is on an old worn out engine. I expect a fresh build with good compression will be easier.

Well I think what happens is that I do flood it. When that happens you are indeed down for the day. Perhaps I need to try starting it in the ways you guys do. I think one big mistake I make is I pump the heck out of the gas pedal with the choke cable pulled out quite a bit.

Steve

[RMS]

one must remember that the throttle pump is not connected to the throttle linkage. the throttle pump is operated by the vacuum signal. by closing the choke you are directing the 2lbs of vacuum generated @ cranking speed to the throttle pump. within 30 seconds of cranking with the coke cable pulled all the way out you will fill the intake manifold. it takes a bit of time for the gas to run out of the manifold and down the Douglas valve into the oil pan. cracking a fitting on the pcv system will tell you if she's flooded.

with idle set @ 600rpm it will require 4 notches on the hand throttle to start.

do not hold the clutch to the floor. the thrust face on the crank doesn't have oil yet. with the proper 50w oil in the transmission there is little drag.

crank for 2 rotations, quickly burp the choke ( a quick in and out) and she should fire.

if flooded crack a fitting on the pcv wait for the gas to stop dripping foot hard on the gas and crank till she starts to sputter

[slk]

Ok guys I called John at Midwest military. He suggested things to check, but also told me how he would try to start the thing. He said not to pump the gas pedal as that does absolutely nothing to help starting. Just like stated above it is a vacuum. He said just pull the choke and let her turn. I did just that yesterday in 30* weather and it took just about 30 seconds and I heard it want to start. Once started I pulled the hand throttle a couple of notches and then just played with the choke as needed once in a while until it smoothed out. Let her run for 20 min, and all seams to be ok. It may have been my starting technique all the time that was causing me grief. Thank all of you for the suggestions and tips. Greatly appreciated...

Steve

[NAM VET]

Easy to overchoke these engines.

NV

[slk]

While we are on the starting subject. How do you guys put new points and condenser in? Do you remove the distributer to do the job???

Update on trying to start it today. Today it started right up in about 5 seconds. I wonder if that is because I ran it yesterday and there was still gas in the carb.

Steve