Hard Starting M35A2

[laxcc18]

I've noticed that the M35A2 takes awhile to start. Usually i have to give it gas while pushing the starter button to get it to idle after sitting. Some say theirs turns over with ease at the push of a button so I'm just wondering how well does your M35's start and should i be concerned or is this normal? Thanks in advance.

 

[gimpyrobb]

Some say that issue cleared up after they bumped up the fuel screw. Others say that its a sign your hydraulic head is going out. Sometimes it is effected by running WMO. I say try turning up the fuel a tad.

 

[laxcc18]

Some say that issue cleared up after they bumped up the fuel screw. Others say that its a sign your hydraulic head is going out. Sometimes it is effected by running WMO. I say try turning up the fuel a tad.

Makes some sense then since I think the previous owner ran WMO in the truck. Guess I'll keep an eye on the Hydraulic Head and turn the fuel up to see if it helps the issue. It only really seems to do it on a cold start.

 

[ken]

Yes turn up the fuel rate. It's starving for fuel at idle. I'm assuming all your fuel filters are clean and the pickup screen in the fuel tank is clean?

 

[laxcc18]

I did all the filters when i got the truck. I'll have to check the screen in the tank. Thanks for the advice. I have some things to check.

 

[deuceman51]

Had a similar problem on a deuce with the FDC bypassed. We backed off the droop screw and the truck now starts in under a second. It used to spit and sputter for almost 30 seconds before. I think it's an 1/8 allen screw, but I'm not 100% on that from memory.

 

[Loco_Hosa]

You specified sitting for a while, its possible that your loosing the prime, and or air is getting sucked up.

(My truck has the same issue, this is what I am planning to do in order to fix the problem.)

-All brand new filters and gaskets
-Remove the in-tank pump, check the hose, make sure its all sealed up. (Good general maintenance anyway)
-Inspect the IP for leaks
-Bypass the FDC (More because I need to bypass it anyway)

Lastly, if I am still having trouble, its time to turn up the fuel.

 

[rlwm211]

I pull my throttle out about 7 clicks and then start the truck. This is typically more of an issue in the colder weather.

I would suspect that the engine needs additional fuel much like a gas engine when it is cold. You would think the high compression ratio would make this eiaser to start but I suspect that the MULTIFUEL aspect of the engine makes it the exact opposite. Once you have any warmth in the engine I am sure it starts easily which tells me it is not a fuel setting in your IP.

Remember that the injection pump has a governor and you are operating the governor when you press the throttle and the governor operatres the pump to produce the RPM that the throttle position is in.

If anything open the droop a half turn or so. This will allow the injector pump to add more fuel to bring the engine up to the speed the pump is set for at idle or whatever speed you are asking for from the engine. This would add enough fuel to help the engine start.

Remember that the fuel pressure setting does have an effect on your maximum temperature in your exhaust system and through the turbo. Too high is not good.

If you are going adjust the droop, the plug should be 1/4 internal hex and the droop is 1/8 and is located slightly below the access hole and a ball ended allen wrench makes this a lot easier to adjust.

I hope this helps and keep asking questions as it is a good way to learn and also spreads whatever knowledge that is offered to a larger audience.

RL

 

[SMOKEWAGON66]

If it hasnt been ran for a while, mine doesnt want to idle either. I just give it very slight pressure on the go-pedal. after 10 seconds or so it idles fine. I always assumed it was just a cold blooded beast lol.

 

[Loco_Hosa]

I pull my throttle out about 7 clicks and then start the truck. This is typically more of an issue in the colder weather.

I would suspect that the engine needs additional fuel much like a gas engine when it is cold. You would think the high compression ratio would make this eiaser to start but I suspect that the MULTIFUEL aspect of the engine makes it the exact opposite. Once you have any warmth in the engine I am sure it starts easily which tells me it is not a fuel setting in your IP.

Remember that the injection pump has a governor and you are operating the governor when you press the throttle and the governor operatres the pump to produce the RPM that the throttle position is in.

If anything open the droop a half turn or so. This will allow the injector pump to add more fuel to bring the engine up to the speed the pump is set for at idle or whatever speed you are asking for from the engine. This would add enough fuel to help the engine start.

Remember that the fuel pressure setting does have an effect on your maximum temperature in your exhaust system and through the turbo. Too high is not good.

If you are going adjust the droop, the plug should be 1/4 internal hex and the droop is 1/8 and is located slightly below the access hole and a ball ended allen wrench makes this a lot easier to adjust.

I hope this helps and keep asking questions as it is a good way to learn and also spreads whatever knowledge that is offered to a larger audience.

RL

On the subject of learning, could you point to me which TM I need to read that relates to the injection pump?

I am still trying to learn the layout of the TMs, and I know I need to better understand my injection pump.

Is a droop screw just like an idle adjustment screw?

 

[gimpyrobb]

The IP has its own TM. If I knew the number, I'd post it for ya. Don't worry, we have a double secret new admin thats going to fix the TM section, I'm sure it will be up soon.

 

[rlwm211]

Well, I checked the Steel soldiers TMs and they are not posted yet.

You can get all the TMs you will need from

JATONKAM35s HOME ON THE WEB

In the Deuce Section.


There are three dfifferent versions of the Deuce TMs not counting the A3s

I would download the TM 9-2320-361 series as they are the newest version and last used while the tricks were still in service. There are 7 manuals that would make a complete set and they are all digital and searchable with linked Tables of conetnts.

You will also want the LO for the multifuel. LO 9-2320-209-12-1

You need the operator's manual and the one in the 361 series is still unavailable as the government still consideres driver instructions for the deuce to be a top secret thing. The older Driver manual will do you just fine.
TM 9-2320-209-10-1

The TM for the INJECTOR PUMP ASSEMBLY is also there and is about 2/3rds the way down the page.
TM 9-2910-226-34

The Droop is the setting that regulates how much extra fuel the injector pump can use to maintain RPM at a specific throttle setting. I explained before that you are driving the governor and not the fuel. You are telling the IP how many RPMs you want the engine to turn and the IP has a certain amount of leeway to accomplish this before you as the operator has to intervene and add more fuel with your foot. Think of the governor on a gas generator.
If you add a little droop, you are making it easier for the IP to add the fuel needed when starting without touching the throttle. I would also add that this may not be any help to your situation and to be honest mine starts the same way when it is cold..

I hope this is helpful...

RL

 

[M35A2-AZ]

One of my trucks does the same thing. Does not run very good when you first start it, but after about 10 sec. it runs at idle just fine.
I was thinking the HD head was losing its prime. But I was not sure.

 

[rlwm211]

I recall that the combustion cycle of the multifuel is one of a steady burn as opposed to a spontaineous ignitiion of a gas or conventional diesel engine. This would make starting a cold engine more difficult as the combusion in a steady manner is a result of temperatures and air flow and a cold engine does not support this well.

If you think about it, a cold engine spews black smoke for a few seconds until it warns a bit after starting. This is poorly and incompletely burned fuel coming out of the stack. The only way to help the multi get started in this case is to add enough fuel so that a large enough explosion occurs so the engine will stay running to the next firing stroke.

Adding fuel overall with the main adjustment may solve this but it also creates an economy and heat problem. Ask me how I know this.

The droop is a more subtle way of solving this while still allowing the IP some authonomy in terms of managing the fuel flow into the engine. I would start with the droop. If the engine starts well but smokes too much on the road under load then you have to lower the droop if that bothers you.

Remeber these trucks were not designed to be environmentally clean at all which is what caused their demise for the military as the tree-huggers are now steering the choices of military engine systems for them now. Smoking to a degree is normal and if you ask Wreckerman he will confirm this.

I hope this is helpful

RL

 

[JeffAS]

My 1971Deuce is doing the same this, you have the push the start button a dozen times before it will start, I am going to start with replacing the fuel filters first before I adjust the fuel

 

[laxcc18]

Thanks for all the info and help. Once it turns over and is running it idles and runs fine just the initial cold start takes some effort. I do want to pull the pump and clean out the fuel tank, screen, and check that hose clamp. I've read that it can be a problem and you guys have confirmed it as well so i think thats a good place to start.

 

[cattlerepairman]

We are now at or just below freezing here, especially over night. Starting the Deuce means cranking with the pedal to the floor for about 5 seconds before she coughs to life; ease up on pedal as she fires, as to not revv the engine over 1000 rpm.

It feels as if the engine needs a few compression strokes to build up heat and then spontaneously fires; not all cylinders fire right away.

Once she idles, she idles, but even with the hand throttle a few clicks out, the idle still hunts a bit. It takes minutes to smoothen out.

 

[Loco_Hosa]

Well, I checked the Steel soldiers TMs and they are not posted yet.

You can get all the TMs you will need from

JATONKAM35s HOME ON THE WEB

In the Deuce Section.


There are three dfifferent versions of the Deuce TMs not counting the A3s

I would download the TM 9-2320-361 series as they are the newest version and last used while the tricks were still in service. There are 7 manuals that would make a complete set and they are all digital and searchable with linked Tables of conetnts.

You will also want the LO for the multifuel. LO 9-2320-209-12-1

You need the operator's manual and the one in the 361 series is still unavailable as the government still consideres driver instructions for the deuce to be a top secret thing. The older Driver manual will do you just fine.
TM 9-2320-209-10-1

The TM for the INJECTOR PUMP ASSEMBLY is also there and is about 2/3rds the way down the page.
TM 9-2910-226-34

The Droop is the setting that regulates how much extra fuel the injector pump can use to maintain RPM at a specific throttle setting. I explained before that you are driving the governor and not the fuel. You are telling the IP how many RPMs you want the engine to turn and the IP has a certain amount of leeway to accomplish this before you as the operator has to intervene and add more fuel with your foot. Think of the governor on a gas generator.
If you add a little droop, you are making it easier for the IP to add the fuel needed when starting without touching the throttle. I would also add that this may not be any help to your situation and to be honest mine starts the same way when it is cold..

I hope this is helpful...

RL

I been reading the TMs, hadn't found the one for the injector pump, so thank you!

 

[rlwm211]

It is 40 here. I just started my deuce to hook up the M105 for a parade tomorrow.

I had to add a little bit of throttle to get her to catch. Once she caught, I let her idle until the oil pressure came up. Then I set the throttle to about 1000 RPM to let her build air and warm up a bit.

Your other choice is to use the manifold heater. Even if it is not working and lighting the fuel it burns, the extra fuel is what your engine is looking for to start when the cylinders are cold.

Once my truck started, I could start it without touching the throttle at all.

RL

 

[Clay James]

Check the fuel line under the radiator. Mine is crushed an I have to do the same thing as you to get it started, and I have to give it a little gas to keep it going for the first 30 seconds, but once its warmed up a little it runs fine with plenty of power. I'll get around to replacing it one of these days, right now I'm fixing much more important, expensive things.
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