My 27 Mhz ZipZap stutters as well but I think it's due to electrical interference with a cordless phone or a baby monitor.
I took my controller apart and my car apart to see if it had the cripple cap but I didn't see it in my ZipZap. My Bit Char-g did have both the caps that causes the range issue and when I removed them, my range was much better.
J
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