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  #1  
Old 07-01-12, 22:43
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Casey B Casey B is offline
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Default M38A1 timing...?

Okay well it's running and the float hand the hole had to be the problem but now timing seems out as it wants to pop and fart when trying to throttle up quickly...although if it is throttled up slowly it does fine.

Not knowing how the spark advance works...I assume its sentrifical weights?
and not vancuum? or both and the vaccuum advance is internal to the disrtibutor? any ideas?

Also to adjust the distributor to at least get it to run well enough is there a place to advce the spark or is it a turn the whole distributor like a small block chevy etc?

I had an English austin that had a ratchet type of small incremneted adjustment that allowed you to adjust the timing by rotating the ratchet one way or the other to adjust and never had to touch the distributor.

Well thanks in advance...Hope I am on the right track...
Casey
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Old 08-01-12, 05:08
rob love rob love is offline
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The advance is purely mechanical...no vacuum diaphragm on a jeep.

To check the timing, you can replace the number one shielded spark plug wire with a normal 7mm or even an 8mm wire with both ends square cut. On that you can use a normal inductive timing light, with only one battery hooked to the power leads (12 volt or you will burn out your light). If you have one of the fancy lights, you can retard your timing on the light by 30 degrees or so, rev up the jeep motor to 2000 rpm, and see if the mark on the pulley goes back to zero.

To check the weights, it's easy enough. Remove the distributor cap, and try and turn the rotor. It should rotate (about 30°) and then spring back to where it came from. You should occasionally oil the wights pivot pin....remove the points plate and the weights are underneath.

To adjust the timing, you loosen the bolt at the block, and turn the distributor.

Popping on acceleration can also be stale gasoline or else spark plugs that are over gapped (30 thou is the correct gap).

Last edited by rob love; 09-01-12 at 04:27.
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Old 08-01-12, 22:53
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Casey B Casey B is offline
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I thought so and you confirmed it...unfortunately the wieghts are seized so they have not seized that long ago as it did run in the summer.
So I am guessing liberal amounts of rustinhibitor and try to move then slowly together outwards? plugs fine new and i did gap at 3 thou as well the leads are good and the rotor and cap look new pomits as well not burned at all.
Oh and finally found the elusive bolt that hold the distributor from rotating. Can't they make anything for large hands?
heater assmebly had to be removed to get in there...
Any ideas about the weights solutions used to free them up will be appreciated?
thanks again Rob! Hows the 105 coming along? ready to invade North Dakota yet!?
LOL
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Old 09-01-12, 04:27
rob love rob love is offline
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I would suggest that you turn your engine to TDC, note the position of your rotor, and yank out the distributor. You have to lubricate both the bushings on the weights, and the upper shaft where it moves in relation to the lower. As often as I have seen the weights seized, I have also seen the springs rusted to the point of imminent failure. You will want to check them as well.

If you want to see the progress on the howitzer, have a look at my thread about it over on the G503. http://www.g503.com/forums/viewtopic.php?f=27&t=189187
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Old 09-01-12, 07:24
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Well the springs look pretty good and got the weights to jiggle in the slots but cant seem to turn the shaft to get them to open. I checked my small block chev distributor and it does move like you said this one should. Put the rotor on and nope won't budge but the weights are now loose but won't open so i am guessing it is the upper shaft that is actually seized. So okay thought I'd have to take it out. It's ready to do so tomorrow.
Thanks Rob and yes will look at the gun now thanks!
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Old 09-01-12, 14:10
rob love rob love is offline
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Remember that the jeep distributor rotates counter clockwise. The shaft should advance left, not to the right.

If you pull the rotor off, you can lube the shaft by putting some oil into the top of the shaft.
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