unhappy_idle

Does the 1988 Honda Accord Carb 2.0L, have an ECU that generates diag codes? If so how can I access it?

The transmission is showing up and refusing to move into 4th gear when in D4. It normally gets worse at this when the car has been driven for around 10 miles. Normally iin D3 if I race to around 40 miles, at 3000rpm and then take my foot of the accelerator, change to D4 the A/T will shift into 4th.


The fluid level in the A/T is ok. The fluid does not smell burnt. I think the fluid is Dexron IV in the A/T.

I am unsure whether the problem is due to engine problems; i.e a vacuum leak,; an old Oxygen sensor that probably needs to be replaced, actual problems with the Vacuum modulator ( does it need adjustment, broken spring etc). I think the A/T on this car is purely vaccum operate, but I am not sure.

Its amazing how little information is available on how A/T's work and manuals etc.

I am interested in knowing if anyone else had similar issues and how they resolved it. If it involves a complete tranny rebuild I probably will junk the car.