Weird RPM problems at highway speeds

Okay so I've always had this problem since I owned it. When driving over 40-45 and above the rpm's are really high around 2000rpms and when you accelerate it will go to 2500 just to reach 55mph on flat ground and almost stay there to maintain that speed. Now the weird part is if you floor it, it acts like it just died and drops the rpm's to where it seems like they should be for that speed. Now if those rpm's were at that speed without flooring it I would be okay. I really hope this makes sense. Just wondering why the hell it does that, when it's to the floor. I just replaced the Exhaust intake gasket, valve cover gasket and the stepper motor. None of this affected how it runs when it comes to this. Only thing I can hope for is that it's the TPS sensor. It is a 1990 renix so it is adjustable. My stepper motor had a ton of carbon so it's safe to assume so does the tps. Can it be cleaned and I also adjusted the TV cable.

Have you done the "free" things yet?

Adjust the throttle pressure cable: http://naxja.org/forum/showthread.php?t=1015963

Test/Adjust the TPS (bookmark this website): http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

Condition of the fluid? Color, smell? Last time it was flushed? Type of fluid used?

Have you tried unplugging the TCU and driving it while shifting manually? You will get 1st in 1-2; 3rd in 3; 4th in D; reverse, neutral, and park. If the problem is gone, then the issue is electric in nature--TCU/TPS/soleniods/harness.

The only thing I haven't done is adjust the tps. I will do that tomorrow.

JoJoDaKilla said:

The only thing I haven't done is adjust the tps. I will do that tomorrow.

Click to expand...

That could be the cause of all the problems.

No the TPS sensor can not be cleaned. In fact a pressure washer is the fastest way to kill one. If its the original 1990 sensor, its more than likely got a dead spot which would explain the tranny not locking up as the tranny sensor uses the TPS to determine torque converter lockup. If you have a good analog meter, that dead spot should be pretty obvious.