90 accord dx transmission

i need some advice folks, i got a 90 accord dx series automatic, if this car sits up over nite or a few hours when you go 2 start it and begin to drive i notice that the transmission will change once and just hold all of the other gears unless you downshift. when this car temperature gauge moves into normal operating temperature the trans will shift normal and fine. i got a buddy that rebuilds 90- 93 accord tcu's and he opened this one up out of this car and he said that he did not see any signs of damage on the circuit board at all and he has seen 100's of accords tcu boxes. could i possibly have a solenoid problem or thermostat? the 90 model dx did not have the sport option so of course i can not see the sport light flashing. i checked the codes last week and then the d4 light flashed only when i checked the code. i took an tcu out of an 91 ex and my car would not shift.

i need some advice folks, i got a 90 accord dx series automatic, if this car sits up over nite or a few hours when you go 2 start it and begin to drive i notice that the transmission will change once and just hold all of the other gears unless you downshift. when this car temperature gauge moves into normal operating temperature the trans will shift normal and fine. i got a buddy that rebuilds 90- 93 accord tcu's and he opened this one up out of this car and he said that he did not see any signs of damage on the circuit board at all and he has seen 100's of accords tcu boxes. could i possibly have a solenoid problem or thermostat? the 90 model dx did not have the sport option so of course i can not see the sport light flashing. i checked the codes last week and then the d4 light flashed only when i checked the code. i took an tcu out of an 91 ex and my car would not shift.



just found out something new today. talked to a master transmission tech ans he said rule out electrical prolems because the shift solenoids would send a signal to make the d4 light flash if they were malfunctioning and so would the tcu. this car has 287,000 miles on it his diagnosis was that either my trans seals internal has hardened and when the trans heats up they expand to let the trans shift normally or there are 1 or 2 valves internally that are not functioning at cold temperature. he said the only thing u can do is add an additive(trans x) to loosen seals and help valve body or just do an complete overhaul on the trans. with that many miles i think i'll go with the additive for now!!!!

Good choice.