94Q Questions

[hoju1301]

Hi there i have a 94Q with about 137k miles on it. When my car is fully warmed up, when in park or neutral, the idle rpm is around 1000-1400rpm, but when put into drive or reverse drops back down to normal speed (650rpm). Im curious to what the problem might be. This was after a valve cover job was done and the throttle body was removed and cleaned, but no screws on it were turned/adjusted. Could the TPS be out of adjustment.?-----------I also recently switched to Mobil 1 ATF and ever since my transmission has been experiencing a slighty shudder/vibration/hard shift around 40mph when accelerating in the city. Never happened with Dextron II fluid. Are the friction modifiers in Mobil 1 different/lacking that would cause the slipping? Ive read that some people are adding the BG transmission conditioner or Lube guard, how do those additives help?---Could both these problems be related to the change in ATF fluid (Castrol Dextron II to Synthetic Mobil 1ATF)

Thanks to everyone in advance for the help!~Anthony

[maxnix]

1.) Do a search on IAC valve.

2.) Do a search on Lubeguard black.

3.) Only 2.) would be affected by the change and previous wear on the transmission. Did you do a pan drop, wipeclean and change the filter also? I assume you had a mechanical fluid eschange and not just a partial gravity drain.