51 M38 - over my head

1952 - 1968, M38A1, M170, questions, discussions, regarding anything related to the M38a1 series.
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GWJ
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51 M38 - over my head

Post by GWJ » Sun Mar 29, 2020 12:33 pm

Greetings I am new (I guess 66 isn’t that new) and a want be mechanic - still working so I have limited time and less knowledge

51 M38 - not started in 25 years - wiring shot but the motor turns, the fluids seem good - my first goal is to see if I can get it started

Has 24 volt alternator, starter, generator, voltage regulator - all to be waterproof, someone has changed the distributor and coil to 12 volt - so I got a new rebuilt 24 volt coil and distributor - that come as one unit and installed that along with the water proof plugs and wires

Still not getting power to the plugs - I have checked the leads on the distrutor with a bulb tester - one shows power when the distributor gap is closed - both show power when open - so I think that is correct -

I would love any tips -

I am in Chapel Hill NC - and still working - I would also like to conscider finding someone in this area or even in NC that could work on this - sort of get me a jump start - no sure how much that would cost -

thanks! best! will

JMZ421
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Re: 51 M38 - over my head

Post by JMZ421 » Sun Mar 29, 2020 5:03 pm

There are 2 condensers on the 51 M38, one in the distributor where the points are and one located in the housing of the distributor. Just checking to make sure you have those(installed correctly and new). It is a M38? as you have this question in the A1 section. John

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Re: 51 M38 - over my head

Post by GWJ » Mon Mar 30, 2020 3:09 am

thanks - the engine is an L134 in a M38 - so I need to move over the the M38 group with this question

will do

thanks

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Re: 51 M38 - over my head

Post by Jeeps4Brains » Mon Mar 30, 2020 10:41 am

You say 'new rebuilt 24 volt coil and distributor', was it bench tested from the place you got it from?

So you are getting power to the points but no spark. There is a You Tube video of how to test an M151 distributor. You can do the same with the one from the M38: https://www.youtube.com/watch?v=EKhQ5sF ... e=youtu.be

Do you remember having the engine at top dead center when you set the distributor in?
45' MB, ??' MBT, 47' CJ2A, 48' CJ2A,
51' M38 #1, 51' M38 #2, 51' M100,
52' M37, ??' M101A1 (1st Gulf War Vet),
53' M38A1, 53' M211, 65' M151A1, 67' M416,
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Re: 51 M38 - over my head

Post by GWJ » Tue Mar 31, 2020 5:04 am

thanks - I don't know if it was bench tests - I got it from Kaiesers - will check with them

best I could tell (using the pencil in the plug hole method and turning the motor) - I have things set properly

thanks fo rthe tips

should I move this over to the m38 forum?

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Re: 51 M38 - over my head

Post by mdainsd » Tue Mar 31, 2020 1:09 pm

You cannot do "pencil in the spark plug hole" with side valve M38 engines. The spark plug hole is over the valves, not the pistons...
52 M38 2X, '52 M37, '44 WC51, '42 WC 56/57, '50 CJ-V35(U), '42 GPW, '44 M3A1 Scout Car, 2010 M-Gator

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Re: 51 M38 - over my head

Post by Jeeps4Brains » Wed Apr 01, 2020 5:02 am

You can put your finger in the number one spark plug hole and turn the engine. You will feel the pressure from the compression stroke. When the pressure stops building you are at Top Dead Center. Back off a smidgen and it should be set for you to turn the distributor for the roter to point to the wire that goes to number one. That's good enough to try and start before final adjustment.
45' MB, ??' MBT, 47' CJ2A, 48' CJ2A,
51' M38 #1, 51' M38 #2, 51' M100,
52' M37, ??' M101A1 (1st Gulf War Vet),
53' M38A1, 53' M211, 65' M151A1, 67' M416,
MVPA #31724

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Re: 51 M38 - over my head

Post by GWJ » Thu Apr 02, 2020 12:57 am

Thanks see photos just to confirm what I have

I have been told L134 engine in an m38 - is that correct? Is this a flat head? Does the term flat head refer to the position of the values?

Still learning


Thanks again!
Attachments
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Re: 51 M38 - over my head

Post by mdainsd » Thu Apr 02, 2020 3:03 pm

Yep, that is a L134 flathead.

You got flat head right, nothing on top of the head because there is no valves or valve train up there.
52 M38 2X, '52 M37, '44 WC51, '42 WC 56/57, '50 CJ-V35(U), '42 GPW, '44 M3A1 Scout Car, 2010 M-Gator

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Re: 51 M38 - over my head

Post by GWJ » Thu Apr 02, 2020 4:28 pm

Thanks - now that I know what I have I maybe I can get it started

Thanks again

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Re: 51 M38 - over my head

Post by GWJ » Wed Apr 08, 2020 7:15 am

First off - let me know if I need to move over the the M38 side -this is a 51m38 L34 flat head - 24 volt waterproof stuff -

Secondly - I cannot get fire to the plugs - I have new rebuilt distributor - I have checked the gap and show power moving when the gap is open - see pictures. However when the gap is open, it seem as if the rotor is not passing the contact in the cap. I cannot advance or retard the distributor enough to get the rotor in that general area when the gap is open. Does that make sense? - I am a novice!

So I am thinking the distributor is set wrong? or I see stuff about the oil pump which seem to be a big job

I appreciate you time and knowledge sharing
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gap is open.jpg
gap is open a.jpg
gap is closed.jpg

JMZ421
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Re: 51 M38 - over my head

Post by JMZ421 » Wed Apr 08, 2020 4:54 pm

You can download the TM9-8012 for the M38 or buy the manual. Inside there are scenarios, for example, when no spark is present, on what to look for.
Now, this manual works well if you have a stock m38 and the distributor is installed correctly. One thought, do you have that rotor pressed all the way down on the shaft? I know they are tight to place on sometimes. Just a thought, John

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