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Old 02-13-2013, 01:25 AM   #4
luvbowties
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Location: southeasternfoothillsofusa
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Thumbs up Re: Help with timing issue

Quote:
Originally Posted by DoubleL View Post
Thanks for your input in advance guys.
I have a new HEI with the coil in the cap. It has full 12 volt power.
I set the timing at 4 degrees advanced with vac advance plugged but when I reconnected it the timing jumped and advanced past the "A" setting on the indicator. It probably advanced 16-18 degrees when I plugged it in. I ended up lowering the timing to "0" so it wouldn't advance so much. The truck idles and revs great but totally falls on it's face going up hills.

What should I set the initial timing to? What should it jump to when I hook up the advance. I have the advance hooked to a port on the manifold is this right?

Any advice would be appreciated. Also it has been verified that the timing mark is correct at TDC.
Thanks guys!!!
Hope others will chime in; but iirc, at least on newer v-8's, timing is set on HEI's with the vac adv hooked to an unported source from our carbs--meaning pulling even at idle. [The modules have increased and decreased 'dwell-curves' built in, which changes timing as dwell changes.]

Sounds like your timing is retarded due to being set on zero w/adv unhooked and plugged. Maybe set it just as you did, except on 4 deg; then up it to as much as 8 degrees, test-driving up those hills at each setting again--over-looking what it jumps to when you re-hook vac. If it ever 'kicks back' on your starter, or if it spark-knocks, lower your setting gradually until that stops. You may also benefit from connecting your vac to a 'ported'(not pulling until throttle is opened) source on your carb.

Your HEI possibly needs a re-curve kit, some which decrease overall advance-swing; but I wouldn't consider one until I tried these suggestions first. What brand/year is it built for?
HTH,
sam
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