I just used Sea Foam on my 1983 280ZX w/ AT. I did the oil crankcase, gas tank & used the tranny lube (haven't had time to spray the throttle yet) & my Z now runs like I remember when she was new... The problem I have now is that when I stomp on the gas in third gear, the tranny doesn't downshift. What can be the problem? Thanks in advance.. And thanks to those who recommended Sea Foam.

 

Maybe you're already going too fast for 2nd gear to keep up.

 

You're kick down might be bad or it might need to be adusted. I don't know if it's adjustable on these cars though. It is on most cars though. Someone else might be able to help you there.

Thats what controls your downshifts.

 

Even going at 45mph it doesn't downshift... just stays in third gear...

 

Actually when I am in second gear, it wont drop to first when I stomp on it!! HELP!

 

It's your kick down man. If you don't know automatic trannies, or where the kickdown linkage is, take it to a shop and have them look at it. It may just need to be adusted, or it could be damaged or broken. There are very few things that would cause an auto not to downshift, and almost all of them have to do with kickdown. And if it upshifts with no problem then I can almost gaurantee its your kickdown. Thats what makes your tranny downshift. So get it check out. Again, I've never encountered the auto trans. on a Z, so I don't know where to find your KD.

Good luck man.

 

OH! Well yes it would seem the button below the gas pedal isn't working.
The way to fix this is to always floor it right from a stop so it revs up to 5K rpms in every gear.

This car only has two gears. Floored and reverse.