The speedometer needle on one of our 89's blips when the engine starts and while car's just inching ahead while riding the brake. Sometimes it blips from at rest to 5-10 MPH and ometimes it blips all the way to 40!!! Needle always comes right back down. At slightly faster (.25MPH?) speed, needle wiggles just enough so you can see it waver. At 2 MPH and faster needle is steady and works just fine. Blips also occur in reverse gear!! Can envision, while car crawling ahead, differential ring-gear sender moving past MPH pick-up unit mounted on differential cover and this trickers blip. It's unnerving while crawing ahead at stop lights. What's happening here and what's the fix? 204K on this car.

Steve in Charlotte, NC 84 5-sp w/300k, 89 5-sp w/173k and 93-940 w/126k that needs engine.