Lock up TC question
06-21-2008, 08:16 PM
#1
Lock up TC question
I have an '87 GTA with the 700r4 and according to my research the 87's came with 3:23 gears. I notice when I am at 60mph the tach reads around 1950 RPM, does that seem high? From a dead stop there are only three RPM drops, shouldn't there be four? I haven't had this car very long so I don't have any idea what may be unplugged or unhooked. Any suggestions what I should look for?
06-21-2008, 08:29 PM
#2
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Car: 89 Formula
Engine: LB9 TPI
Transmission: 700R4
Axle/Gears: 3.73(coming soon)
Re: Lock up TC question
the 700r4 cant shift into OD at WOT(i think safety thing)..but can be modded to remove that.....your tach is prob a lil off
06-24-2008, 09:58 AM
#5
Re: Lock up TC question
But wouldn't the fourth interval be the TC locking up? Or could the TC be locking up at the same exact time it shifts into 4th? When I'm cruising at 60mph and I let off the gas, and then press it again, I should be able to see (and hear) the TC unlock and then lock again. I'm not seing that.
06-24-2008, 07:50 PM
#6
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Re: Lock up TC question
Maybe, but you might have your foot far enough into it that the TCC isn't locking up, or the lock-up could be coincident with a gear change. You should be able to make the TCC lock and unlock at some point, though... try grounding the TCC pin on the ALDL.
06-25-2008, 01:52 PM
#7
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Car: 1985 Berlinetta
Engine: Megasquirted TPI
Transmission: Transgo 700R4
Axle/Gears: 3.42
Re: Lock up TC question
To see if the TCC is locking, get on the highway at cruising speed.
After a few minutes, give gentle throttle and observe the rpm. Then, step on the brakes just hard enough to trigger the brake lights, but not slow the car in any way. This will unlock the converter and you should see the RPMS increase by about 200.
Hope this helps.
After a few minutes, give gentle throttle and observe the rpm. Then, step on the brakes just hard enough to trigger the brake lights, but not slow the car in any way. This will unlock the converter and you should see the RPMS increase by about 200.
Hope this helps.
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06-25-2008, 02:34 PM
#8
Re: Lock up TC question
To see if the TCC is locking, get on the highway at cruising speed.
After a few minutes, give gentle throttle and observe the rpm. Then, step on the brakes just hard enough to trigger the brake lights, but not slow the car in any way. This will unlock the converter and you should see the RPMS increase by about 200.
Hope this helps.
After a few minutes, give gentle throttle and observe the rpm. Then, step on the brakes just hard enough to trigger the brake lights, but not slow the car in any way. This will unlock the converter and you should see the RPMS increase by about 200.
Hope this helps.
06-25-2008, 02:41 PM
#9
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Car: 1985 Berlinetta
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Re: Lock up TC question
Trace the wire from the 4 prong plug.
It will have three wires. One is +12v, One is 4th gear signal and should ground when the car shifts into fourth, and the other is lockup.
Ground the lockup wire to test the convertor. IIRC, it is a blue wire.
It will have three wires. One is +12v, One is 4th gear signal and should ground when the car shifts into fourth, and the other is lockup.
Ground the lockup wire to test the convertor. IIRC, it is a blue wire.
01-31-2009, 04:53 PM
#11
Re: Lock up TC question
Okay, I have updates. I tried grounding the ALDL pins, still no lock up. Today I dropped the pan and changed out the TCC solenoid, took it for a spin and the TC still doesn't lock up
. The only thing I can think of now is the wire coming from the ECM must be shorted somewhere. I'm also running a 180 stat, but surely that's warm enough for the converter to lock? I suppose the converter itself could be bad, but wouldn't that cause shifting problems?
. The only thing I can think of now is the wire coming from the ECM must be shorted somewhere. I'm also running a 180 stat, but surely that's warm enough for the converter to lock? I suppose the converter itself could be bad, but wouldn't that cause shifting problems? 
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