M38 wont start without starting fluid

Discussion topics on Willys Overland M series vehicles
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ih8pepl
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Post by ih8pepl »

Jeff_Lee wrote:
wesk wrote:... it is functioning and partially disolved.
Wes, I am missing something on the "partially disolved" statement. Are you concerned that the diaphragms are desolved by ethanol fuel?
This actually leads me to a question I was going to ask, Ive only used ethanol free 91 octane and it still has enough clean agent additives to do a number on the diaphragms. Could the octane level have anything to do with the startup issue? I never had any issue with it before. Its the only constant in the equation and the one thing I haven't tried swapping out.

Update: Just for giggles, new fuel pump and new carb diaphragms... still nothing. Still starts right up with starting fluid. I dont get it.
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wesk
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Post by wesk »

I corrected the dissolved typo.

Going back a bit to check missing replies. Are you using the correct thick insulation gasket with the metal “V” gadget in the middle?

Have you checked for vacuum leaks using the propane enrichment process?

Have you performed a leak down test of the cylinders?
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

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4x4M38
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Post by 4x4M38 »

Did you preload the diaphragm spring on installation?
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ih8pepl
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Post by ih8pepl »

Been a while so I thought I would do an update...

I just skipped to the back of the technical manual and followed the instructions on proper disposal of the Jeep. Problem solved.








Ok im not there yet... I verified my valve clearances, did a leak down test, checked my timing, points gap, and all vacuum lines. Rebuilt the carb with all new parts and had the fuel pump rebuilt (slight oil seep).

Jeep will not start on its own... unless the crossover tube is removed or at least disconnected from one end. Aside from a slightly higher idle from the tube being removed it runs better than ever - drove it around the block a few times with no issues.

Still scratching my head on this...
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wesk
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Post by wesk »

Is there a chance you have the air/oil cleaner overfilled??? Thus heavily restricting air flow to the carb.
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php
RonD2
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Post by RonD2 »

ih8pepl wrote: I just skipped to the back of the technical manual and followed the instructions on proper disposal of the Jeep. Problem solved.
Hilarious! Me thinks it's very good to have a sense of humor in this hobby and forum! Shot beverage out my nose with that one --- thanks for the laugh!
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

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ih8pepl
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Post by ih8pepl »

Just read about overfilled oil baths on a tractor forum with a tractor that had the same issue the M38 is having.

A week ago, I had the oil bath filled to the fill line... cleaned the filter element out with kerosene and refilled it with conventional 10w30. I just took out half of the oil - no change. For giggles I will fill it 1/4 of capacity tomorrow and see if that changes anything.
RonD2 wrote:
ih8pepl wrote: I just skipped to the back of the technical manual and followed the instructions on proper disposal of the Jeep. Problem solved.
Hilarious! Me thinks it's very good to have a sense of humor in this hobby and forum! Shot beverage out my nose with that one --- thanks for the laugh!
Ive owned multiple generations of Jeeps - every one has been quirky as can be. When they work you love them, when they dont you want to take a cutting torch to them...

Id rather blow a piston through the side of the engine than deal with elusive annoying problems like this starting issue. Im just rolling with the punches.
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Scott21
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Post by Scott21 »

Is the intake manifold flush with no leaks?
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