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356-930 356-930 is offline
Acceleration Junkie
Join Date: Aug 2007
Location: Laguna Beach, CA
Posts: 263
Originally Posted by billjam View Post
My '86 930 seems very flat below 3500rpm . . .The car has been checked over by local specialist . . . They set timing and CO at idle but car would hardly run at all with correct idle timing so they had to shift timing back (clockwise) to what it was (= advanced?).
1. the small vacuum hose from bottom side of distributor was squashed flat between the IC neck and manifold.
2. the cam timing (with std cams) was at 0.20mm (should be between 0.65 and 0.80mm).
My question for the gurus is ... are these two issues likely to be sufficient to significantly reduce power below 3-3500 rpm?
1. If timing was set at idle with the vac line pinched off, the engine was missing a bunch of timing. Even under boost, it was still missing timing as it had only centrifugal advance. (Advance due to loss of vacuum and centrifugal advance with distributor shaft speed are additive.)
Turning the distributor clockwise advances timing.
2. Not knowledgeable about cam timing.
3. I'm no guru, just a gear head.
Old 04-21-2008, 06:57 AM
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