Slant Six Forum
https://slantsix.org/forum/

converter lockup behavior with vacuum switch & start
https://slantsix.org/forum/viewtopic.php?t=38485
Page 1 of 1

Author:  kafer65 [ Sat Jan 02, 2010 8:31 am ]
Post subject:  converter lockup behavior with vacuum switch & start

Since the lean burn computer is gone I'm using the chevy low vacuum switch to unlock the converter when I hit the gas and manifold vacuum drops. This switch is connected to the ported vacuum on the carb. The same place where the vacuum advance is connected. I just tested it and it does not unlock when I lift off of the throttle. Vacuum gauge is attached. I have to use the manual on/off switch I installed in the cab to break the 12 volts and unlock the torque converter.

One other behavior that perplexes me is that I used to be able to split the gears with the lockup if I manually grounded the lockup wire myself. Now that I have it running throught the start relay it only activates lockup after its in third. Interesting.
________
BMW R 1150 GS history

Author:  SlantSixDan [ Sat Jan 02, 2010 2:54 pm ]
Post subject:  Re: converter lockup behavior with vacuum switch & start

Quote:
Since the lean burn computer is gone I'm using the chevy low vacuum switch to unlock the converter when I hit the gas and manifold vacuum drops. This switch is connected to the ported vacuum on the carb.
Hook it to manifold vacuum instead.

Author:  AnotherSix [ Sat Jan 02, 2010 4:32 pm ]
Post subject: 

The way the lockup is setup on most computer-less cars is with the vacuum switch like you have ( with direct manifold vacuum like Dan Said)as well as a brake pedal switch to break the circuit when the brakes are applied. The main switch used to lock the converter is usually a pressure switch on the trans tapped into the high gear circuit, third gear in this case.

Locking and unlocking the converter, locking it while accelerating under power, will usually kill the converter clutch rather quickly. The converter clutch has only one friction and is meant to apply at light throttle settings, not full throttle upshifting.

Author:  SlantSixDan [ Sat Jan 02, 2010 6:06 pm ]
Post subject: 

See this thread and follow the link it contains.

Author:  kafer65 [ Sat Jan 02, 2010 6:27 pm ]
Post subject: 

I drove it more today and it likes to be warmed up pretty well first. I think the butterfly isn't being returned to the closed position enough to cover the vacuum port sometimes. It also tends not to want to come unlocked when its cold. Once thoroughly warm, that does function. It locks too early which takes care of any high power lockups, but it does unlock when the pedal goes down enough to hit the vacuum threshold.
________
vapor tower vaporizer

Page 1 of 1 All times are UTC-07:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/