R33 GTST Auto Issues

[Morgan12]

R33 GTST Auto Issues

Hi there, I am new to the skyline family but I am having some issues as of late.  My car is a 1993 Auto R33 GTST Skyline 4 DR Sedan. No real major mods. It has been running fine for approx 6 months and now I am having issues with auto box.  Upon starting it revs at 1200-1400 rpm for 10 mins then drops down to 500-600 rpm. When it does this, the gears will not change until I hit higher rpm between 3500-4500 rpm. Does this in cold weather more often.  Please any advice would be appreciated 

[GTSBoy]

Could be just about anything.  A serious contender would be the throttle position sensor.  It plays a part in idle behaviour and tranny behaviour.  But it could also be something that is only affecting the engine speed (like a failed cold start valve or IAC) or it could be a vacuum leak, or it could be a transmission failure that the TCU is sending a signal to the ECU causing the high idle (and the tranny failure eventually makes it not shift properly when it gets warm).

By far your best bet is to loosen the bellhousing bolts from the back of the engine, remove the tailshaft, remove the transmission crossmember and shake the car vigorously over a scrap metal bin.  When you hear a loud banging noise, your problems will be mostly better.

But if you don't want to do that, I suggest getting a proper workshop grade scantool onto the Consult port and look for codes that might explain it.  Some of the possibles I listed above should turn up that way, regardless of whether they originate in the ECU or the TCU.

[niZmO_Man]

Changed the transmission oil yet?

[hardsteppa]

OP, does sound like could be a tps issue. If you search, there are how-to's about putting r33 auto trans into diagnostics mode; suggest you try this and see if it registers any tps fault.

[Morgan12]

I should've mentioned I have changed the TPS and cleaned out the IAC valve extensively twice.  Also replaced the coolant temp sensor and had the tranny fluid and filter changed. None of the above have fixed or improved. Tried to do diagnostics mode but unsuccessful due to lack of operator knowledge

[GTSBoy]

scan tool