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1970 Transmission Controlled Spark- help


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I've been battling a 'just-off-idle' stumble on my '70 98 since 1975. Well, OK, I was just a kid then, but I well remember the stumble.<P>Now at age 35, I figured a decent rebuild of the carb and a new accel pump would fix the problem. Not.<P>I've replace ALL the vacuum lines, checked this, that and everything else it seems, but still can't find the source of the problem. It happens at any speed, in any gear, no matter how easily you transition the pedal from idle to just off, it is like someone pulls the plug on the ignition. There is NEVER an intake backfire.<P>I knew that there was some funky vacuum sensor that was linked to the tranny when I replaced the lines, but never followed up in the shop manual. Tonight I did, and I'm wondering if this damn TCS system could be causing the problem.<P>Anyone out there have experience with this? What is it supposed to do anyway? The best I can gather from the schmatic, it may give more voltage to the coil when in 3rd gear...

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All TCS is supposed to do is eliminate distributor vacuum advance until the transmission is in high gear. It's entirely possible that sticking mechanical advance weights are causing this problem; combined with no vacuum advance in lower gears, it could well be the problem. Lube the weights with some WD40 and make sure they swing freely. Then try running distributor advance straight from a ported vacuum source on the carb, bypassing the TCS switch (Just don't trash it, the 442 hardcore restoration crowd will do bizarre things to get them wink.gif" border="0 ).

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