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Old 04-15-2008, 10:21 PM
techron techron is offline
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Quote:
Originally Posted by strokey
Techron - I'd love to have the link, Ive been reading old posts for hours trying to diagnose.

I think I've finally narrowed the problem.

I spent time blaming my sour performance on the stock stall converter and stock highway gears, then the swap meet 650 holley double pumper with a kit in it.

I bought a brand new box stock holley 670 and noticed much crisper throttle response in park, yet the same completely no idle/stall when in drive.




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this sounds about right to me, i think you are on the right track. you need a vacuum advance with a weak enough spring to advance at idle . 12 degrees at idle with no vac advance with that cam is going to make the engine idle like crap. as far as a specific part # i can't hepl you there--i think the link i made for you may have some talk about low vacuum at idle engines IIRC.

OOPS, got it in the wrong place, just imagine this is at the bottom, i don't want to type it all over...

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I'm running a 388 ci sbc with a comp xe284h. The car makes 6-7 hg" of vacuum in gear at 800 rpm's.

Ive been blaming the drive train/running gear for the high idle it needs in park in order to sustain a sufficient idle when placed in gear. Here is what I think my problem is.

The car has a real sweet attitude idling at 1300 in park. This is probably at the point where it is producing a good ammount of manifold vacuum.

When the car is placed in gear the rpm's drop and it immediately falls on its face and stalls.

I think this is because of the non adjustable factory style advance canister. It is providing no advance in drive ( at 600-800 rpm's, again making 6-7 hg" of vacuum).

In a nutshell to even have the car driveable I was running at 1300 rpm's in park. I have now realized that at this point (in park) the vacuum advance is running at full clip providing an additional 15 or so degrees of timing, thus a total of around 27. Then when you switch to drive and the rpm's drop (as well as manifold vacuum levels) you are back to the base timing of around 12 degrees (because the canister is providing little or no advance at this point with such a low ammount of vacuum).

Simply there is no happy medium with this cam and this advance canister with this configuration.

I need an adjustable can badly.

I may be preaching to the quire.

But someone please let me know if I am on the right page.
now i get the lengthen my post to 10 characters message.
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