Hi I am new here. I have a good beater 91 Civic 4 door LX Automatic that I like to keep for commuting. It has a shifting problem and will not shift into 4th from 3rd until it is warmed up for over an hour. I have change the ATF fluid and bought a new shift solenoid to no avail. Been driving it like this for 10 years.
There are four different versions of the 1991 Honda Civic Automatic transmissions that went into the cars of various models for this year. I bought a replacement transmission with exactly the same part number as the one in my car from a junk yard. It looks the same but has a double shift solenoid valve switch on top instead of a single shift solenoid switched valve like the one on my car. The two pin connector fits from the junk yard transmission (double solenoid) but my wiring harness on the car has only one wire (to control a single solenoid shift valve). This surely will not work as there is no signals to send from the cars CPU to the second solenoid. Is there some way to make this work? Is there some other 91 Automatic Transmission part number with single solenoid style I should be looking for? This needs to be answered by someone who is a Honda Civic Transmission expert. There must be someone in the US who knows this answer? The car is a very good Honda with nice paint that runs great and passes smog clean if the trans can shift, (34 MPG). Out of time now as the Reg. is coming due soon. Still paying insurance on it, i.e. it is still derivable now but only goes about 35 MPH.

Thanks in advance
Lonesomedave