Hey all-

I've read the 700 series FAQ backwards and forwards since I aquired my '88 745 turbo two weeks ago. Thanks to all that contributed- it has really helped quite a bit.

My biggest gripe with the car right now has to do with the tachometer reading. At what sounds like an 850 rpm idle, the car's tach is registering 1500 rpm. Floor it and wind 1st or 2nd gear, and the needle's buried. Running the m46 in OD shows 3000 rpm at 60 mph. I don't believe it for a second. My parts guy looked and listened and agrees with me.

I've cleaned and No-loxed the grounds in the engine compartment and beneath the fuel computer. No change. I tightened the 1/4 spade terminals at the computer- no change. I removed the instrument cluster, inspected the boards, used Wurth cleaner on all contact surfaces (which looked clean) and tightened every screw as firmly as what felt safe. I used a knife blade to tighten the terminals in the wiring harnesses' connectors. NO CHANGE.

I've seen the speedometer jump at a complete stop once or twice. The reading on the road seems about right- I haven't timed it yet. The rest of the gauges seem right on target, but the tach is grossly out of whack. Should I go ahead and pull a tach from a junker and give that a try? should I try running a new lead from the coil to the tach? Anyone seen a failed tachometer that acted like this?

Thanks-