Started once...kinda, but now nothing

[nathan66669]

OK, me and my buddy have gotten our hands on a '52 (I believe) M37. I have to say we were impressed with this american made machinery (this truck is almost 30 years older than myself). I know very little about machinery of this era, and after spending 2 hours trying to figure out how to even start it, we could not get it to go.

In the bed was a spare motor. We pulled the dist. cap off and saw there was very little spark on the points. So we pulled the dist from the spare and noticed the tapered edges on the bottom shaft were 180 degrees off, so we swapped all the plugs 3 spaces (180 degrees).

With a spray bottle we sprayed fresh gas into the P trap for the air intake and got the motor to run for a few seconds at a time. Our assumption was bad gas/dirty carb.

So the next day we pulled the carb off and drained the tank (nice that they maufactored a drain plug in the tank). Carb looked spotless, and there is already a clear fuel filter. Reassembled and now it won't fire. We can see fresh gas getting through into the carb (even tried starter fluid in) but not getting it to run. The starter is just chugging along (seems kind of slow compared to newer vehicles) and every couple of seconds we get a bit of a chug out the tailpipe like it tried to fire, but it just won't start.

I'm not very familiar with these old style condenser distributors (or carbs) but am looking for some checks. Just can't understand why it ran a bit but nothing now.

Thanks,

Nathan

[k8icu]

Well, first off what batteries do you have. One 12 volt or two 12V wired in serries to make 24 volts? These trucks are made to run on 24 volts and if you only have 12 volts hooked up that may be the reason for a slow crank and low or no spark.

You said you pulled the distibitor did you pull the cove off? If so make sure that the cap is on correctly and secure. Also make sure the distibutor didn't turn or rotate on you as that can affect timing as well.

You need three things to make the engine run...fuel, spark and air. Make sure you have all three. Pull a spark plug and check it for spark. Did you hook up to the fuel pump on the block or are you gravity feeding the carb? Is the fuel pump pumping fuel. If you sprayed starting fluid and still nothing then I'm leaning towards no spark, so check that out completely to make sure you've got that.

Good luck and keep us posted.

[Lifer]

"...after 2 hours trying to figure out how to even start it..."
Should we reveal the secret, guys, or is it still classified?

If the engine in your truck is a stock military engine, it's impossible for your distributor to be 180 degrees off. #1 cylinder is at the 7 o'clock position on the dist cap. Put your plug wires back in the right holes! You moved 'em, and that's why all you get now is a little puff now and then.

You admit that you're not familiar with points/condenser ignition systems and carburetors. This lack of knowledge is understandable considering the advancements made in automotive techology since you were born, but you're not the only one suffering from it. Since you have the courage to admit it in a public forum, all is not lost! My suggestion would be to find a really old guy (such as myself) in your area, ply him with the beverage of his choice, and listen very carefully as he explains these things to you. He will welcome your interest and teach you many more wonderful things about all things mechanical.

Welcome to the group, and by all means...enjoy your truck!

[nathan66669]

"...after 2 hours trying to figure out how to even start it..."
Should we reveal the secret, guys, or is it still classified?

Oh I figured it out...I laugh now, but I just imagined in my head the number of people throughout the years that did the same as me

If the engine in your truck is a stock military engine, it's impossible for your distributor to be 180 degrees off.

I tried and tried to get it to go in (rotor button was facing plug#2) but it would only go into the hole 180 out facing plug #5. I'll try to post some pix

My suggestion would be to find a really old guy (such as myself) in your area, ply him with the beverage of his choice, and listen very carefully as he explains these things to you. He will welcome your interest and teach you many more wonderful things about all things mechanical.

Anyone on this forum live near Madison Indiana?

Welcome to the group, and by all means...enjoy your truck!

Thanks!!!

Well, first off what batteries do you have. One 12 volt or two 12V wired in serries to make 24 volts?

I do have 2 batteries

You said you pulled the distibitor did you pull the cove off? If so make sure that the cap is on correctly and secure. Also make sure the distibutor didn't turn or rotate on you as that can affect timing as well.

The first distributor seemed to have weak spark so we just swapped with the spare. How in the world do I even begin to time this puppy? My timing light doesn't come close to clamping over the plug wire.

You need three things to make the engine run...fuel, spark and air. Make sure you have all three. Pull a spark plug and check it for spark. Did you hook up to the fuel pump on the block or are you gravity feeding the carb? Is the fuel pump pumping fuel. If you sprayed starting fluid and still nothing then I'm leaning towards no spark, so check that out completely to make sure you've got that.

At first we had little spark, then after the dist swap we didn't get it to turn over unless spraying gas into the air intake with a spray bottle. We just thought bad gas...I'm going to double check the carb again and make sure all lines are hooked back up. I remember reading a post here somewhere stating the vacuum lines on the carb are nessesary for proper fuel ressure?? I'll check there, maybe a crossed line? I'll update later.

Thanks for your help.

[k8icu]

I would like to recomment that you find the Technical Manuals or TM for this truck. The Army manuals are very good, give trouble shooting steps and can help you find and fix many issues.

[MSeriesRebuild]

Give me a call at the shop tomorrow, I'll answer your questions & talk you through the set up procedure. 704-474-4683, ask for Charles.

[TOM R]

there is an adapter you buy to put inline on the sparkplug wires so you can hook on the timing lite, first thing we did when we bought ours was new points and condensor and welcome, call charles he is a big help

[nathan66669]

OK guys, sorry I have been really busy and my internet was down for a while. I did get a chance to look back into some things.

We checked compression. Had 80~90 psi on all 6 cylinders with the throttle open. I know this is a bit low (120 seems to be the norm) but we figured it should run with that.

Also, we found that when we took the batteries off to charge, we put them in backwards. Turns out the red wire was ground. I'm going out on a limb and saying that is why it would not run the second time. Anyhow, we got the points gapped correctly, got it set TDC (which I realized takes two turns of the crank). Messed a bit with the fuel mixture and she started up. We had a ton of smoke (grey) and had to evac the garage (30x40 pole barn w/14' ceilings).

Next task was getting brakes working. Spent a few hours on that and we headed out on the maiden voyage. Down the driveway and up a decent hill. Pretty much had to floor it in 2nd gear to make it, so it severly lacked power. Before making it to the top of the hill engine started to die. There was a bunch of smoke (not quite as much as in the garage). And she would not start back up.

So we coasted back to the garage. Rechecked everything. Points, timing, plugs/gap. Plugs 1, 2 and 3 (1 and 2 more heavily) were fouled black. 4, 5 and 6 looked clean. I cleaned the plugs out and again she fired up (very little smoke this time). I had a wire shoved into plug 1 and wrapped it around the spring on the plug wire and was able to clip my timing light onto that, which worked. I figured it may be out of time a little, but it was actually pretty close. Tweaked that in a little better (I assume the plug is supposed to fire right at 0 deg TDC? I know some Fords, like the 302 times at 10 deg, but I set it to 0 degree). It sounded pretty good running. Not like a purr of a modern engine, but more of a putt putt and chugg like older vehicles have.

This time I made it out 10 feet in reverse and had so much white smoke I couldn't see where I was going. Truck had no power and was dieing again. I pumped the gas a bit and could keep it running, but it definatley did not have all 6 cylinders firings. Shut it off and rechecked plugs, and again 1-3 were blackened.

I'm not an experienced mechanic, but isn't white smoke mean burning oil? We were thinking maybe bad rings or even bad head gasket? A buddy of mine has an old timer that lives across the street, we think he worked on these back in the army, but due to poor health, he can't help us. He did suggest valve guides could be the problem.

What do you guys think? Also, how hard of a job are we talking here?

We also took a better look at the spare motor in the bed. It was dated as a 72 I think. But looks like it was not guarded well against the elements. There were seeds inside the intakes. There was also rust and mouse poop inside one of the plug holes on the top of the cyclinder. I think that motor is trashed as well.

[Lifer]

Your lack of power after tinkering is due to your timing being retarded too much. It should fire at 8 degrees before TDC.

On the smoke issue, unburned gas usually results in black smoke. Burning oil usually results in blue smoke. White smoke usually indicates water.

From what you describe, I'm guessing that it's time for a rebuild.

[nathan66669]

Your lack of power after tinkering is due to your timing being retarded too much. It should fire at 8 degrees before TDC.

On the smoke issue, unburned gas usually results in black smoke. Burning oil usually results in blue smoke. White smoke usually indicates water.

From what you describe, I'm guessing that it's time for a rebuild.

indeed!
Biggest problem is I personally don't own this vehicle. If so, she'd already be in pieces on her way to a full restoration. As it stands I may one day own it and give it the care she deserves.

That being said, if there is water in the cylinder, that means head gasket or cracked block right? Crack can't really be fixed, but head gasket isn't too hard is it? Autozone sells one I believe (PN 7564C). I know it's a lot of bolts, but with the valves on the side, should be easy replacement.

[MSeriesRebuild]

Your timing should be set at 4 degrees before TDC. 0 is not good, 8 degrees before is way too far advanced & will cause spark knock like you read about.

80-90 PSI compression is not good at all, it will likely skip intermittently on 1 or more cylinders. Don't expect any power out of that. You are lucky it will fire off. Cracked blocks are a fairly common sight, usually no way to successfully repair.

White smoke usually means timing off or coolant is in the mix, blue smoke will be oil.

Not at all likely a bad head gasket is the problem. I've known of lots of folks thinking that would fix a coolant in oil issue, have never known that to fix one. If you see oil in the radiator as is typical with a cracked block, it is highly likely that you are wasting time to do anything but search for a known good block. Once you have that, then you can make some headway.

[Lifer]

Thanks for the correction on the timing, Charles! I realized my mistake and went back to edit my post, but by the time I went to do that, I had lost my internet connection. Nice to have you covering my @$$!

[nathan66669]

Your timing should be set at 4 degrees before TDC. 0 is not good, 8 degrees before is way too far advanced & will cause spark knock like you read about.

80-90 PSI compression is not good at all, it will likely skip intermittently on 1 or more cylinders. Don't expect any power out of that. You are lucky it will fire off. Cracked blocks are a fairly common sight, usually no way to successfully repair.

White smoke usually means timing off or coolant is in the mix, blue smoke will be oil.

Not at all likely a bad head gasket is the problem. I've known of lots of folks thinking that would fix a coolant in oil issue, have never known that to fix one. If you see oil in the radiator as is typical with a cracked block, it is highly likely that you are wasting time to do anything but search for a known good block. Once you have that, then you can make some headway.

OK, I'll check for oil in coolant. Then clean the plugs and re-time it to 4 deg prior to TDC. I can probably deal with low power for now until we can get a rebuild. I just wanna see it in action before we spend more time/money on it.

I truely appreciate your help!