2000 ZX2 Engine RPM's High

Last night when I got onto the interstate my RPM's on my car shot up to 3.5 on the dial when its normally around 2.5. I was at 60 mph when suddenly the engine RPM shot up to 3.5 and stayed there. I slowed down to 50 mph and it stayed at 3.5. Any Ideas as to the problem? I stopped for gas and when I restarted it acted normally. :uhoh:

If its and automatic your OD kicked out and kicked back in. Could be a tranny sensor...

If its and automatic your OD kicked out and kicked back in. Could be a tranny sensor...Yeah its a automatic. Hmm. It stays in high RPM's until I come to a complete stop. Happened in the exact same spot on the interstate tonight also. Trans sensor ok I will look at that first. Thanks.

Same thing happened to me rpms would shoot up just by moving. O2 sensor was bad and hadn't thrown code yet. I have a 5 spd.