Timing problems. (1 Viewer)

Joined
Sep 24, 2012
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I have a 2F engine with a GM HEI distributor. I can time it in the shop and it idles great, and will run smoothly at all throttle settings for about 3 minutes. Then it start s stumbling and quits running. At that point the timing is found to be 4+ degrees off. Resetting the timing starts the process all over again. Distributor gear appears to be in good condition. Any idea what might be happening? How likely is it that the mating gear is stripped, and if so what's the best way the replace it? Valve timing does not appear to be affected by this issue.
 
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Sep 24, 2012
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Too obvious. The clamp is tightened down. Couldn't rotate the distributor with a crowbar. Clamp has to be loosened to reset timing after each test. Is it possible the timing gears are bad (crank and camshaft)?
 

JohnnyC

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Is the gear on the dizzy slipping ?

Is it a store bought conversion? .... Or one from a GM car/truck? From junkyard ?

Do you have a stock dizzy to throw in and see if it does it with that?
 
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Oct 5, 2009
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If the distributor has mechanical advance, I would check its operation. If there is any slop, the mechanism may not be returning to the base position.
 
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The distributor gear is pinned to the shaft, so it isn't going anywhere. The cam gears are keyed, so they can't slip. The clamp for the body is a known problem because the GM body is too slim for the Toyota clamp. The centrifugal advance is a potential problem as noted by the Colonel above.
 

JohnnyC

Long ago TLCA# 2231
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I have seen the pin on the disributor fail and the gear moves... happened on my fathers bronco and another friends Ford product... could just be crappy Ford stuff :) I dont know if this is also a problem on GM stuff ...

... but... if he got his stuff from a junk yard .... who knows the condition of any of it
 
Joined
Sep 24, 2012
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Is the gear on the dizzy slipping ?

Is it a store bought conversion? .... Or one from a GM car/truck? From junkyard ?

Do you have a stock dizzy to throw in and see if it does it with that?
Gear not slipping. Store bought conversion. Same problem with stock distributor. I'm baffled!
 

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