Hi, new here hope you can help. Just like title, the convertor locks and unlocks at highway speeds. Seems if I push the gas pedal after an unlock it will lock again, then 30 secs later unlock. I can control this with the gas pedal. What do you'all think?

Thanks Jed

 

Had the same problem on my 93 EX. It would lock when trying to accelerate, then unlock when you lifted your foot. With the cruise control on, it would lock when starting up a hill, then unlock when you got to the top (backwards, seemed to me). There is a cable to the transmission that is operated by the throttle. If I remember correctly, I shortened that cable (based on discussion with local Honda service shop foreman) by about 1/2 turn at the transmission end and it now operates correctly.

 

Well the first thing is that the TC should lock and unlock at highway speeds, depending on the engine load.
The adjustment cable goes from the throttle body to the pressure lever on the front of the trans.
If it is adjusted correctly this is the driving test;
go along a level road under light throttle at 25 mph, floor the gas pedal and the trans should downshift to first gear.
Repeat the same drive at 27-28 mph and floor the gas pedal, the trans downshifts to SECOND gear.

It's a little confusing but, when the TC locks up the rpm increases a couple hundred RPM. You are now using the stored energy of the TC to spin the engine/trans, however that energy can't sustain itself, so the TC unlocks and the engine then is doing the work again.
Thats a very basic explaination.

 

If I am not mistaken, when the TC locks, the rpm should decrease a couple hundred rpm. The TC works like one fan blowing against another only using oil. The part of the torque converter driven by the engine will always (under load) be turning a little faster than the transmission input shaft. When the lockup clutch engages, there is no longer a speed difference between the engine and transmission input (just like a clutch in a manual transmission), so at any given speed, the rpm will drop.

 

Can't believe anyone hasn't said this, CHECK YOUR TRANS FLUID!


PS: When TCC locks your RPM's go DOWN.

 

Thanks guys fluid level is good, I'll look at tightening what sounds like a throttle valve cable. I was thinking it might something like throttle position sensor?
Jed

 

Check your coolant and thermostat. If your engine doesn't get up to temperature the TC won't lock. This happened to me last winter. You could be on the boarder line between warm up mode and normal mode.

 

Bet me $1,000,000,000,000,000,000 dollars?

 

I'll check coolant level and t-stat, thought gauge registers normal. Whats the bet on?
Jed

 

sounds like a bad torque converter

 

fleetwood, thanks got a chance and shortend the cable 1/2 turn works great now.THANKS

Jed

 

Sorry to bring an old thread back from the dead. I used the search feature to find this thread.

My 96 Accord was doing the same thing described here. I just wanted to say tightening the cable fixed my Accord too. I had to go a bit more than 1/2 turn, but the converter locks up great now at highway speeds. Anyone having this problem, this seems to be the cure. A very small adjustment can make a big difference.

 

change your t-stat