Hello; I have just bought a 1991 Accord EXR. This is my first Honda and I love it. It only has 148.000 Kms. on it. The only problem I have with it is sometimes the transmission lock-up will work and sometimes it won't. When it does my tach drops about 300 RPM. My cousin owns a automotive shop in Calgary and when he was down I told him about it and he said first thing to try is to change the transmission fluid, so I did and it did not help.Is there anything else I should check? Is there any way to check the lock-up solenoid valve to see if it is sticking and is there any way of cleaning it if it is sticking? Is it easy to change the valve? I see it only has an electrical plug and three small bolts that hold it on to the transmission? Does it hurt my transmission if it does not go into lock-up? I would appreciate any help you guys could give me on this problem. Thanks again for your time! George.