Automotive Forums

Please help, I have searched and read and read and searched but am stumped at present.  I have a '90 Acura Integra with an automatic 4 speed tranny.  This tranny has a s3/s4 switch that allows you to manually control that switch point if you desire.  All worked fine until about 2 months ago... then it started with a noted delay switching between 2nd and 3rd... but only when cold.  Once it shifted all seemed to shift fine for the remainder of the day.  The problem has gotten progressively worse with it now taking about 10 min. of 4-5000 RMP running before it will shift.  Once shift occurs... will work fine until cold again... longer the wait between drives... the longer it takes to shift.

I have replaced the tranny fluid... it seemed to help but I now think that it was just hopefull wishing as it is now the exact same as before.

There are two solenoids on this tranny... does anyone know their functions?  I beleive there is a seperate TCM (tran con module) on this car but unsure what all it is monitoring?  Could it be a simple input to this module causing the problem or is the tranny just toast?  I have rebuilt/replaced many engines but have not done much with these trannies before.  

Have you come up with any solution?  My 1990 Integra RS has the identical problem.  
I have found that I can force it to shift a little sooner by bringing the RPM up to about 4000, let off the accelerator at the same time putting the trans into neutral, coasting a second or two, then putting it back into drive. This works about half of the time.
A friend that is a general mechanic suggested flusing the transmission as a start.  I plan to try it.  

There is a 3rd 90 Integra with same exact symptons - I'm leaning towards an electrical problem rather than a mechanical problem. I am doing research on this problem and hopefully will have a fix for this problem sooooon