93 300zx trans



new trans,works off and on dealer wants $575 to diagnose tps voltage signal.something not telling trans to work right, also is it necessary to replace knock and oxygen sensors for $2800


If the throttle position sensor isn’t working right, you will have engine problems as well as transmission problems. Knock and O2 sensors only affect the engine and would give you a check engine light, at least the O2 would. If the knock sensor isn’t working, you engine will sound like pebbles shaking around in a tin can every time you accelerate.

What exactly is not working in your transmission and is it an automatic or manual? These clues are needed if you want a good answer. Give as much information as possible. There is a transmission expert on this site, but give him something to work with and you will get a good answer.


throttle sensor replace twice. trans shifts late. engine sounds like its racing before it will shift. occasionaly it will work. nissan says knock sensor and o2 sensors are bad. there is no warning lights on and no sounds like pebbles but s ometimes a rubbing sound when taking off, for 5 years it takes a few minutes for the car to go from a cold start. gas pedal can be pushed to floor and car will still not go for a few minutes just hesitates. mechanics say its just old and takes a while to warm up but can be dangerous to pull out in traffic. also sometimes engine will just shut off when slowing down or coming to a stop. it is an automatic with 82,000 miles


The engine performance problems need to be tackled, first, and in some order:
Problems: "The car will not accelerate from a cold start. And, the car stalls during deceleration."
A. After changing the dirty fuel filter, check the fuel pressure at idle, and at 2000 rpm (if possible) with transmission in Drive.
B. Examine/replace the spark plugs, and possibly spark plug wires.
C. Use a throttle body cleaner to clean the air intake tract, idle air control valve, throttle bore and throttle plate.
D. Clean the MAP (manifold absolute pressure) sensor.
E. Check the response of the engine coolant temperature sensor.