About 400 miles ago, I completed a partial restoration of my ’69 280SL. The engine was rebuilt (including the FIP by the legendary Gus at Pacific Injection Service). The Crane ignition system was replaced with a 123 system. Even the upshift switch works. I installed air conditioning (a long, expensive adventure of its own). I am very pleased with the final product. The linkage is set. The CSS is being used to keep idle speed up under A/C load. My mechanic and I can’t figure a way to use the CSS for idle-speed-in-gear AND A/C. So, right now, the CSS is just wired for A/C.
What keeps me from being extremely satisfied is a problem that involves shifting. If I accelerate normally from a stop, in fourth gear, the car winds out and shifts normally. I can engage the upshift switch and move into third gear just fine. But if I manually select third gear, the engine has a fit! It misses, sputters, and backfires through the intake manifold. After shifting back to fourth gear, takes several minutes to recover. If any of you have an idea what would cause this, I’d love to read about it.
