halftrackinfo
general discussion => ALL mechanical and technical related questions => Topic started by: Cleprechaun on September 22, 2020, 02:23:39 AM
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I consider myself a pretty good trouble shooter and I have solved several mysteries on my halftrack, but this one has me stumped. It doesn’t like to start after Iv driven it for an hour or so. It starts easy in the morning. It runs great. It’s charging. It idles and revs up fine. It never gets hot and runs at about 160. Every great now and then I get a puff of blue smoke. When it’s good and warm, and you hit the starter button, the motor is slow to turn over and can take a minute to start, which is an eternity While at a gas pump. About the time you think the battery is dead, it starts. Holding the gas pedal down doesn’t seem to help and pumping it doesn’t help. My last three guesses are either the carb is dumping gas in the motor after I shut it off, or the starter is hot and taking up all the juice (I’m running 1 large 12 volt bat.) or there is a timing issue. I did a dump run today and nearly got stranded at a gas station.
Any ideas?
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I’m certainly not an expert but if you audibly think the starter is slow, it could be worth looking into why. Try a jumper cable from starter to a good earth and see if it speeds up. A bad earth usually gets hot so it could be worth just carefully feeling each earth to see if there’s one that’s V hot. Worth a try as it costs nothing.
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Yep. Had the same problem. Your engine is getting hot because your timing is off and basically boiling your gas (vapor locking) your engine. Check the counter weights in your distributor to make sure they are installed correctly and reset your timing. My counter weights were installed backwards in the distributor before I got the track, and I heard from others that it could be the problem. That should take most of the problem away. Also helps to shut the gas flow off a minute before you shut down the engine to starve the carb a little.
Steve
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Great comments ..as BP suggested start with your engine ground strap, battery ground etc. they could be loose or making poor contact and all ground points should have two star washers (top and bottom of the strap) to help them seat correctly against the metal and bolt. My track only had a single washer on the engine ground when I recovered it as did the battery ground strap, I also cleaned up the metal so that the straps would have good contact with the body.
Had a similar vapor lock issue issues with a M37 after it had heated up. Landed up insulating my fuel line and the bottom of the carb, and the problem immediately stopped regards vapor lock. Summit Racing has all kinds of insulation goodies for vehicles.
Do you know the condition of the brushes in your starter or the condition of the armature and bearings. if there is any wear regards bearings, armature etc. its enough to create drag in the starter, especially if its been heated up.
Please keep us posted on the outcome.
Mark
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Yep. Had the same problem. Your engine is getting hot because your timing is off and basically boiling your gas (vapor locking) your engine. Check the counter weights in your distributor to make sure they are installed correctly and reset your timing. My counter weights were installed backwards in the distributor before I got the track, and I heard from others that it could be the problem. That should take most of the problem away. Also helps to shut the gas flow off a minute before you shut down the engine to starve the carb a little.
Steve
I have heard in the jeep community that people in the USA are suffering a lot with vapour lock even when correctly timed IAW the correct manual. The main problem being that modern fuels are much better quality with additional additives. Quite a few have resolved the issue by timing using more modern methods resulting in timing being a lot different to the original WW2 recommendations.
I believe the Californian gas has particularly high percentage of Methanol and ethane which likely brings its own issues.
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Ethanol in gas is just plain BS and added to prop up that whole Fnnn industry >:( .. make corn liquor instead!!
Some states are awesome because they offer fuel at the pumps without it. Ohio is not one of those states!!!!
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I have a clear fuel tank on the ranch! But all my components will take ethanol fuel.
Don G.
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UP DATE
I checked the timing and found two things, my timing was dead on and the manual seems to have a horrible mistake in it. Shouldn’t the rotor point TOWARDS #1? See photo.
Tomorrow I check grounds and possibly pull the starter.
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Did you check the counter weights in your distributor? If the are in backwards they will retard your timing on acceleration not advance it. Which will make your engine run hot.
Steve
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Yea, no I re-read that a bunch of times . Its worded goofy or just wrong. My guess would be to chalk it up to the way people used to talk. Probably means the the contact on the rotor would be "opposite" the gap between the rotor and cap on #1. Hope you find your gremlin soon!
Will.
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UP DATE
I found a couple loose plug wires in the distributer cap. The rf shielding can tended to squish the wires around. I also replaced the main grounding cable star washers back to the original, more aggressive, washers. I cleaned up and tightened the battery terminals.
After all this I did notice a minor increase in starter RPM during cranking, and an even smoother running motor. It ran great before, but didn’t like to start when hot. I only took it out for a 20 minute test drive so I haven’t gotten it nice and hot for a real test yet.
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UP DATE
I drove it for about 60 miles on a round trip on a hot day last Saturday. I went to go visit my old ultralight buddies at the Perris airport. It started every time just fine, but it does crank slower when hot. The problem was three things: loose plug wires in the distributor. Poor ground. Slightly tired starter that doesn’t like heat.
Man, do those floorboards get hot!
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60 miles. That’s a good test drive.
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A nice ride!!!
Good workout for body and ears!!!! ;)
Keith
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Are there starter rebuild kits available, I see NOS armatures but I wonder how sound the windings are after 40, 50, 60 plus years.