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Old 08-12-2007, 01:07 PM
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Connect the vacuum advance to a full time vacuum source. Every chevy I ever worked on had better throttle response, better mileage and ran cooler with it connected to a manifold vacuum source. Every time it was connected to a ported source, it was real sluggish, ran hotter and the mileage would go down. Part throttle mixtures are leaner so they burn slower, this is why the additional advance is needed at idle and off idle. I asked the same question many have asked because I didn`t believe it either, I would say "why do you need vacuum advance at idle?" But I also wondered why on GM catalysts it would say set the timing with the vacuum advance disconnected and plugged. Then I couldn`t stand it anymore that my car was a complete sluggish turd, it wouldn`t burn a tire to save it`s life. BOBCRMAN of this site that`s highly respected for his knowledge, told me to connect it to a manifold source, I did and it made a huge difference.
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