Sounds like Pam's Datsun needs a solenoid adjusted.
My problem is a 1982 Datsun B210 (no, that's not the end of my story). When I start the car, I must start it in gear, any gear, until the engine warms up. If I leave it in Neutral, or try to shift gears while driving, as I pass through Neutral, the RPMs go wild and the engine screams. So on frigid winter mornings (and all other mornings), I huddle in the front seat with my foot on the clutch until the engine is warm enough not to send it's parts into orbit. Three mechanics have been stumped by my little bomber. Do you have any idea what it could be?
RAY: I know exactly what it is, Pam. I happen to have gotten my M.D. in B210s.
TOM: M.D. is "Mechanic of Datsuns." And by the way, he got it at MIT: The Massachusetts Institute of Transmissions.
RAY: There's a device on the carburetor that raises the engine's idle speed when the car is in Neutral, and lowers it when the car is in gear. It's activated by a switch on the transmission. The device was put there for emissions reasons, the details of which I don't remember because I dropped out of the MD/PhD program in Datsunology before we got to that course. But I do know that the device (which is called an "idle up solenoid") is adjustable.
TOM: Find someone who's worked on these cars--or someone who has the shop manual--and have him adjust the solenoid for you. Then you'll be able to spend more time driving and less time huddling.