Hi my name is Austin, im from san jose california. I currently own a 1978 280z as well as a 1993 240sx, and a 1995 240sx. My problem is with my 280z. I think its the transmission but Im not a mechanic so im not sure. Basically my problem is whenever I smash on the gas the rpms shoot up but the car doesnt accelerate as it should. Any ideas as to why this is happening?

Maybe your clutch is slipping. Try taking your foot of the clutch from a stop with the brake depressed. if the car doesn't stall or move it could be your clutch. I've heard this little from someone and have never tried it myself, but it does make sense to me, so I thought I'd pass it on. Just a suggestion, hope it helps, good luck.

Does the car have an automatic or a manual transmission? If a manual, it is almost certainly the clutch.

Manual Transmission: Your clutch is slipping. Either it is worn, soaked in oil, or the pedal is not adjusted properly. You will in all likelyhood need to replace the clutch and have your flywheel resurfaced as the slipping action will roast and warp the flywheel. Installing a new clutch onto a scortched flywheel will eat your new clutch in a very short period of time.

Automatic transmission: When Auto trannies start to slip, it's not economical to fix them. Replace with either another transmission or another drivetrain completely.