Help - unusual gauge activity with hesitation

[der Mond]

The '87 Carrera was running perfect in the fall. After re-start it ran perfect initially, then the gas gauge started wavering, then the tach needle began strangely zeroing as soon as I lifted throttle, them wavering widely. At first the only unusual run problem was a hesitation at 4500 rpm, then the rough running and bucking eventually came and went at any point in the rev range, and more frequently. Any ideas?

[rick-l]

The gas gage system is pretty stand alone and isolated from the engine controls so your gas gage problems are probably coincidental.

The tach indications going away could be a big clue to your running problems. Are you a purist or a parts shotgunner? You will get 15 replace the DME relay replies and that part could well be suspect.

[der Mond]

I put my spare DME relay in - no change. My alternator reads steady 13.7 - 13.8 at idle, and rock-steady 13.86 from 2500 on up. When I go WOT to 4500 rpm it bucks like a bronco, and the tach wavers wildly upon deceleration. Then the tach continues to zero and waver every time I decelerate. I'm a long way from a Porsche mechanic, guys, please help!