Hi, I have a 1992 Accord. I am now experiencing lockup issues. The car jumps in and out of lockup at speeds above 50 when cruising with neutral acceleration. When I accelerate it locks up. It jumps around 300 RPM when it jumps out and its only for a moment. I have looked online for a solution. I have found several theories but no definite cause or solution. Any ideas?

 

Check for any stored codes.
Verify your grounds are good, there is a main harness ground that is attached to the thermostat housing, verify it is there and not loose/damaged/corroded.
Verify the connections to the upper pair of solenoids(lockup) are in good condition.
Verify the solenoids work properly. Apply battery voltage directly to each solenoid, it should 'click' on/off.
If any work has been done recently, recheck the work and verify nothing is loose/missing.
Verify the transmission fluid is full. Ideally car is parked on a flat surface and the dipstick should have fluid up to the middle of the hash marks.
*On older ATs I'd suggest leaving the engine running, get it up to temp, place it in every gear for a few moments to charge each circuit. Leave the engine running. Pull out dipstick, wipe off, reinsert fully, pull out and check level. I prefer the fluid to be at the upper limit of the hash mark on an older well used trans. Especially if you live in a hilly area. These transmissions when they get older tend to drain down a bit faster.
If it is a surging/stumble/misfire it may simply be that your EGR ports are clogged and need to be cleaned. If the car has over 80K miles and no record of this has been done it may just be this.
Back probe the various sensors, MAP, TPS, ECT and verify they are working and within range.
TPS verify the voltage is a smooth linear change from closed to open throttle and back. A dead spot or erratic voltage change on the TPS can cause odd shifting issues.
Verify the two shaft speed sensors located on the right side cover are not covered in gunk/slurry. These can affect shift quality.
Verify the engine is in good working order, engine operation greatly affects transmission operation.

 

Mike, Thanks for the info. I replaced the TPS trying to get rid of a stumbling issue which ended up going away after new dist and wires were installed. I made slight an unmeasured move on the TPS today and I believe the lockup problem got worse. I didn't have time to correct it, but I feel I'm on to something. Thanks again.