For the longest time (since I bought the car, really) I have been having strange shifting problems. The first and most alarming issue was a strange grinding in 4th gear around 37-40 with light throttle applied. The second problem was the car randomly deciding the shift late and deciding not to downshift after that point unless the car was stopped and restarted. The third problem was just a general harshness of shifting. If any of you are experiencing ANY of these problems, I have found the solution. It is not really one simple thing, rather, it is a system of parts that need to be adjusted and working together properly.
All adjustments are nearly pointless (except for the TPS) if your throttle cable is not adjusted properly.
1) Make sure that you're throttle cable is adjusted properly at the rotor. You want it to engage right away when you press on the pedal. Remove all play by adjusting the locknuts on the bracket on your plenum.
Step 2 was the solution to my 4th gear grinding problem.
2) Adjust your throttle control cable. This cable runs to the transmission. It is easy to adjust; simply push down on the throttle control lever (this is on the transmission, where the cable attaches) until you can't move it any farther, and remove all play by adjusting the locknuts properly. Then have someone depress the accelerator pedal and make sure you DO have a small amount of play when pulling the throttle control level up (you should be able to pull it up about 1/2" even with the gas pedal fully depressed).
Step 3 was the solution to my random shift delay and absence of downshifting problem.
3) Make sure your TPS is properly adjusted if it has been modified or changed. This was the most difficult problem to diagnose. First, with the ignition on, put your positive probe on the yellow/white wire, and your negative probe on the green/white wire on the TPS connector. You should read 5V. If you don't, check the wiring going back to the ECU. Then you can backprobe the connector on the drivers shock tower to check the TPS itself, it is the red/black wire. Connect the negative probe right to the negative post on the battery and the positive probe to the red/black wire. With the throttle plate closed, you should get a reading of 0.45V, with it wide open, it should read approximately 4.96-5.0V.
Step 4 solved my harsh shifting problem.
4) Make sure you don't have burnt or old transmission fluid. If you haven't flushed your transmission previously, now is the time to do it. I HIGHLY recommend Honda ATF-Z1, it made a large difference over cheap Wal-Mart brand ATF. Yes, it is expensive, but it is very much worth it. When flushing the transmission, you will want to drain it, fill it with fresh fluid, then drive around until the car reaches operating temperature, then drain and fill again. Overall, you want to drain it three times, and will with fluid 3 times. This makes sure to get rid of ALL traces of the old, burnt fluid. You may wish to use cheaper ATF for the first drain and refill, but I highly recommend using Honda ATF-Z1 on the 2nd and 3rd refills.
If these above steps don't fix your shifting issues, please chime in and explain what the issue is, and I will do my best to resolve it and add the solution to this list.
I hope this helps some of you dealing with shifting problems!
All adjustments are nearly pointless (except for the TPS) if your throttle cable is not adjusted properly.
1) Make sure that you're throttle cable is adjusted properly at the rotor. You want it to engage right away when you press on the pedal. Remove all play by adjusting the locknuts on the bracket on your plenum.
Step 2 was the solution to my 4th gear grinding problem.
2) Adjust your throttle control cable. This cable runs to the transmission. It is easy to adjust; simply push down on the throttle control lever (this is on the transmission, where the cable attaches) until you can't move it any farther, and remove all play by adjusting the locknuts properly. Then have someone depress the accelerator pedal and make sure you DO have a small amount of play when pulling the throttle control level up (you should be able to pull it up about 1/2" even with the gas pedal fully depressed).
Step 3 was the solution to my random shift delay and absence of downshifting problem.
3) Make sure your TPS is properly adjusted if it has been modified or changed. This was the most difficult problem to diagnose. First, with the ignition on, put your positive probe on the yellow/white wire, and your negative probe on the green/white wire on the TPS connector. You should read 5V. If you don't, check the wiring going back to the ECU. Then you can backprobe the connector on the drivers shock tower to check the TPS itself, it is the red/black wire. Connect the negative probe right to the negative post on the battery and the positive probe to the red/black wire. With the throttle plate closed, you should get a reading of 0.45V, with it wide open, it should read approximately 4.96-5.0V.
Step 4 solved my harsh shifting problem.
4) Make sure you don't have burnt or old transmission fluid. If you haven't flushed your transmission previously, now is the time to do it. I HIGHLY recommend Honda ATF-Z1, it made a large difference over cheap Wal-Mart brand ATF. Yes, it is expensive, but it is very much worth it. When flushing the transmission, you will want to drain it, fill it with fresh fluid, then drive around until the car reaches operating temperature, then drain and fill again. Overall, you want to drain it three times, and will with fluid 3 times. This makes sure to get rid of ALL traces of the old, burnt fluid. You may wish to use cheaper ATF for the first drain and refill, but I highly recommend using Honda ATF-Z1 on the 2nd and 3rd refills.
If these above steps don't fix your shifting issues, please chime in and explain what the issue is, and I will do my best to resolve it and add the solution to this list.
I hope this helps some of you dealing with shifting problems!
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