Hard starting--install a primer?

[Caldwelljj0]

My truck is really a hard starter. It is running the stock etw1 carb recently rebuilt and the stock engine with an electric fuel pump. I recently had it worked on by a well regarded local carb expert. He suggested installing a primer before the carb to help it start without spraying staring fluid or grinding the starter for several minutes. That or he said go back to manual fuel pump or change carbs. I don't really want to change out to a non-stock carb. Anyone have any suggestions? Has anyone installed a primer on their truck?

[RMS]

i though all m37 came with a primer and jets on the manifold ? i was thinking of converting my primer pump into a upper cylinder lubricator / fog machine that would inject white oil in to the combustion chamber

the electric pump should fill the bowel before you start to crank. I cant see how going back to a mechanical pump would make it easier to start.

how orange is your spark or is it red? do you set the choke and pump the gas pedal or do you give the choke a blip when cranking? do you know the pump circuit in the carb will not deliver gas until there is vacuum?

the procedure i use when starting my truck is: (1) turn on batteries, (2) turn on fuel pump and wait until it clicks slowly, (3)power up coil, (4) two notches out on the hand throttle, (5) press starter plunger (6)after one second of cranking quickly pull the choke out all the way and immediately slam it back in, (7)if she does not fire repeat 5 and 6 if she fires pull the choke out 1/8th to 1/4th of the way or until she idles smoothly. (8) as she warms up slowly push the choke in and push in the hand throttle. (9) if the carb ices over and there's no throttle response. shut off truck wait 5min and repeat 5 and 6.



hope this helps

[w30bob]

Hi guys,

The dash mounted primer was discontinued in May of 52 and not installed in M37s after SN 80026807. What his mechanic probably means by telling him to go back to the mechanical fuel pump is that the M37 pump has a hand priming lever on it. But like you said....the electric pump should fill the carb quickly once energized.

regards,
bob

[RMS]

discontinued in May of 52 and not installed in M37s after SN 80026807

my bad. must be a 9140 thing my 53 m42 has one, so does my buddy's 53 m37

[52 M-42]

When the primer pump was discontinued as a factory standard item it was moved to the arctic kit; so, depending on where your truck went, it may or may not have had one. If in was in Korea, it may have had one. If it was in Alaska it may have had one. Some trucks in Viet Nam had one because the trucks came from Korea (they also had heaters for awhile in VN, which was a running joke about Army cluelessness).

So some trucks have them and some don't. My truck has one and I used to use it in the winter (even though it doesn't get THAT cold in Washington state) and it helped the truck to start right up. I would try to start on cold days and if it didn't start within a few revolutions, a shot from the primer pump and it would start right now.

I haven't used it this winter yet because the engine is rebuilt and the truck lives indoors now in a 65 degree garage.

It now starts right up within a couple of revolutions.

52 M-42

[Kaegi]

like someone else mentioned maybe you have a spark issue. even a starter that is drawing too many amps can cause hard starting. or a vacuum leak? tighten carb? these trucks are not hard to start generally. I was in Whitefish MT in 39 below F with 79 below windchill and the only rigs the Big Mountain resort was running was M37s. I asked a guy driving one why they were not driving the 8 or so 1 year old chevy 1 ton dually trucks they had lined up with 3 feet of snow on the roofs and he said "they wont start" he jumped back in the M37 and drove away with confidence.

[Kaegi]

moe easy starting proof. found this on youtube.

http://www.youtube.com/watch?v=6805j-HkEeo

[RMS]

nice looking truck in that vid, thanks for sharing Kaegi.

(they also had heaters for awhile in VN, which was a running joke about Army cluelessness)

thats funny

discontinued in May of 52 and not installed in M37s after SN 80026807

my bad. must be a 9140 thing

failed joke attempt that it must be a canadian thing to have a primer pump

[MSeriesRebuild]

Have you done a compression test? In many cases I've seen these test results tell you definitively why there is a hard starting issue. Most people look into tune up stuff as a first fix when this occurs. Many times the issue is deeper than that. The smarter place to start if you don't know the compression readings is with a simple compression test, easy, only takes a few minutes, and will tell you volumes about the actual condition and how much life is left in your engine. Will cost you way less than a carb rebuild too. If the readings are not at least 105 PSI per cylinder or higher, then your hard starting issue is not the carb, or any other accessory component. Get a good feel for actual engine condition. If that checks out good, then look into tune up stuff such as a good spark, carb issues, etc. Doing the tune up route first will be completely fruitless in fixing the problem of hard starting if deeper issues are the problem.

[Caldwelljj0]

Thanks for the advice guys. Sorry I have been away from the truck for awhile and have not had a chance to check back in.

Charles, I am hoping i do not have compression issues. This is a take out engine I bought from you a year or so ago that had great compression readings then, so I will check compression but I don't think there is a major issue there. At least I hope not.

Perhaps the spark is the place to start. Not sure. The truck loves to run once it is going, it is just not fond of waking up. I guess I know the feeling!

[MSeriesRebuild]

Thanks for the advice guys. Sorry I have been away from the truck for awhile and have not had a chance to check back in.

Charles, I am hoping i do not have compression issues. This is a take out engine I bought from you a year or so ago that had great compression readings then, so I will check compression but I don't think there is a major issue there. At least I hope not.

Perhaps the spark is the place to start. Not sure. The truck loves to run once it is going, it is just not fond of waking up. I guess I know the feeling!

I thought this might be the engine you got from us, it had great readings, so I doubt that being the issue; however it is still a good place to start, cheap, and then you know it absolutely is accessory component issues before you spend money.

[oilleaker1]

Before you go through a bunch of work, make sure your choke cable is in fact working. Next if you have a electric fuel pump like I do, the fuel pressure needs to be checked and a visual of flow at the carb. Take the fuel line off the carburator and point the end at a coffee can and have a friend turn the power on but not try and start. The fuel should pump straight up about 6 inches. If it barely comes out, you need to set the regulator higher or clean the filter or replace the filter if it has one. If the float in the carb is sticking and not letting fuel in, it won't start either. Tap lightly with a soft wood handle or plastic handle near the carburator fuel inlet. The "drill on both mine" is pull out the choke, turn on the switch , engauge the foot starter and crank about 3-4 seconds and as soon as the engine fires, shut off the choke. Then keep it running with your foot for a little until the engine warms up. They just love gasoline! John