Mazda 323 auto gear box when engine up to running temp and been driving for about 15 mins it keeps wanting to change gear culminating in the hold light flashing...and lumpy when slowing down or speeding upany ideas

trade it in quick or fit a manual gearbox this is expensive

most likely u have bad syncronizer. does it have winding noise why you hold it in 5th gear?

adjust the idling screw on the carburetor. turn clockwise the screw.

why does hold come on dashboard

It sounds like you need to service the transmission,new filter and fluid should clear up this problem.

You could say, as a rough estimate, 2500-3000 RPM is probably the most you should rev the engine in a 323.

i know its your ranny problem. clutches are burnt and need changing. it may be more guaranteed to get another tranny.

It could be a faulty ignition module or igniter in the distributor. Ask an auto electrician to verify it and change it. jw

even i had the same problem but try to take off ur AT oil and take off the filter of the AT gear box for this u can screw off the nuts of the sump of the AT gear box and then take the filter off and replace it by another then before replacing the filter keep the gear box to draw off all the oil which was there and then eplace it and put new gear oil

run the engine for a while about 4-5 days and again put on to a dignoser and reset the gear box settings
i think this will work