I was running on the interstate coming home this evening in the 88 765 and felt the cart buck once. I thought at first it was the road, then the tach went nuts slamming 0 to 7000. The engine died so I moved to the right lane and nursed it off the highway into a parking lot where it crapped copmpletely. The first thought was one of the fuel pumps or the relay so I grounded the wiring for the high boost cutout (this used to be a turbo) and turned on the ignition to run both pumps. Both pumps ran and I could hear fuel in the rail. I then started the car and it ran fine for about a minute then rough then cut off. As I was waiting for AAA (I don't leave home without my gold card!)the ignition was on, and I saw the tach go into the wild swinging movement. What I noticed was that when the tach was normal the car would start but no fire when it was erratic.

My question is what could cause the tach to go nuts with the engine off and the ignition on besides a failed tach, which I know would shut down the engine if it was going to ground. The Hall sensor was changed when the engine was replaced about two years ago.

Regards,
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Will Dallas, www.willdallas.us, www.willdallas.org, www.willdallas.com, www.dallasprecision.com 86 245 DL 222K miles, 93 940 260K miles, 88 765 GLE 152K miles, 88 780 246K miles, 93 Buick LaSabre 119,000 miles