68 289 distributor questions......
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68 289 distributor questions......
I have driveabilty issues with single vacumn advance distributor but have been told this engine had dual vacumn advance distributor. Is there any reason why a single vacumn advance distributor wouldn't work on this engine? I was told its getting too much advance at higher rpm. Car runs good up through 3000 rpm or so and then when pedal is nuetral, not accelerateing or declerating, engine misses, jerks and just seems to spit and pop. Engine is all newly rebuilt and been tuned lots of times but just can't seem to get rid of this condition. Thanks for any advice.
Postmaster
Joined: Mar 2005
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From: Earth
Where is the initial timing set? And what is the total mechanical advance?
Make sure the vacuum advance is going to a ported vacuum source - i.e. no vacuum when the throttle plates are closed.
What distributor it came with shouldn't matter. Is it a points distributor? Lots of stuff that could need to be replaced/adjusted if so.
Make sure the vacuum advance is going to a ported vacuum source - i.e. no vacuum when the throttle plates are closed.
What distributor it came with shouldn't matter. Is it a points distributor? Lots of stuff that could need to be replaced/adjusted if so.
Cargo Master
Joined: May 2007
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From: British Columbia
"Car runs good up through 3000 rpm or so and then when pedal is nuetral, not accelerateing or declerating, engine misses, jerks and just seems to spit and pop."
So this is occurring in a "cruise" driving condition only? Does it happen under load at this same rpm?
If it's okay under load then I would guess it's carburetion. There's no reason a single vacuum advance distributor would inherently cause misfiring.
If it misses under load as well, it could be point bounce or incorrect gap (dwell).
So this is occurring in a "cruise" driving condition only? Does it happen under load at this same rpm?
If it's okay under load then I would guess it's carburetion. There's no reason a single vacuum advance distributor would inherently cause misfiring.
If it misses under load as well, it could be point bounce or incorrect gap (dwell).
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Iv'e got initial timing at 8 degrees but I'm not sure about total advance. No points have petronix. Carb was rebuilt by Pony Carbs and don't think that is the problem. Distributor was also rebuilt, new bushings etc. by Advanced distributors out of Minnesota. I'll do some more testing and I really don't want to change to a dual vacumn distributor. Thanks for the advice.
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Iv'e got initial timing at 8 degrees but I'm not sure about total advance. No points have petronix. Carb was rebuilt by Pony Carbs and don't think that is the problem. Distributor was also rebuilt, new bushings etc. by Advanced distributors out of Minnesota. I'll do some more testing and I really don't want to change to a dual vacumn distributor. Thanks for the advice.
If you decide to get a new distributor, consider our custom curved Duraspark Distributor built with our new Full Length Oil Impregnated Bronze Bushing. The full length bushing improves timing stability and spark scatter. If stock appearance is not an issue, take a look at our one piece D.U.I. Distributor. Whether you choose the Duraspark or the D.U.I., we curve each on a distributor machine based on your engine combination. Please see them at:
http://www.performancedistributors.com/forddistributors.htm
Also, there is now an excellent installation article on the D.U.I. Distributor on the Ford-Trucks.com site at:
https://www.ford-trucks.com/article/idx/0/358/article/DUI_Ignition_Installation_In_A_Ford_351W_V8.html
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From: Louisville,Ky.
You need to install the correct timing tape on the balancer and see what the total advance is. Sounds like it's too high. Try 3000 with the vauum advanced blocked off. If the miss goes away, then you are getting either too much vacuum advance or too much mechanical advance. If your distributor has the large vacuum diaphram, then you may need the small one. I had this problem on a 460.
Performance distributors has nice hasnice stuff. I have one of their DUI units in a 351W.
Performance distributors has nice hasnice stuff. I have one of their DUI units in a 351W.
