To add to this, when doing a turbo swap with an 87-88 auto ecu and an A4LD trans, here is the additional wiring for the auto trans:
Pin 37/57 (VPWR) provides power (+) to the 3/4 shift solenoid and the converter lockup solenoid.
Pin 42 (3/4 shift) When the computer grounds this pin, the 3/4 shift is enabled provided that the transmission speed is sufficient to use overdrive.
Pin 53 (CCO) When the computer grounds this pin, torque converter clutch is allowed to lock up. To prevent a rough feel, the coverter lockup is inhibited at certain speed upshifts and downshifts, brake on, cold engine, etc.
The above three connections terminate at a single 3 contact connector mounted on the transmission.
Pin 3 (VSSDIF+) One terminal of the vehicle speed sensor.
Pin 6 (VSSDIF-) Other terminal of the vehicle speed sensor.
The two connections above terminate at the two terminal connector of the vehicle speed sensor mounted on the transmission at the conventional speedo cable location.
So, that should be pretty straightforward wiring it up. Looking at the Ford manual for the A4LD and the wiring diagrams, it appears that having all this unhooked would just result in a 3 speed automatic (no overdrived, no lockup clutch on the torque converter.) So unless the transmission has some preexisting problem I wouldn't think it would cause any problems to operate it disconnected. But for best fuel economy and to lower overall engine RPMs most of us would like to have it all fully functional as intended.
Furthermore, the service manual refers to the solenoids and computer as a means to override (via the computer) the otherwise mechanical 3/4 shift and converter lockup. So, if you just grounded the two solenoid terminals on the transmission and hooked VPWR to the common terminal on the transmission you would get 3/4 shift all the time and converter lockup all the time. In other words, leaving the computer out of the picture would give you a purely mechanical 3/4 shift and a converter locked all the time. (That would be a pretty rough shifting transmission. The computer is needed to negotiate smooth 3/4 shifting and converter lockup.)
If you did want to "manually" control the 3/4 shift and lockup you could hookup the VPWR to the trans and then have two separate toggle switches to ground the solenoids leaving computer pins 34 and 53 disconnected. You could then manually control overdrive and converter lockup but it would take a lot of manual switch flipping to approach a smooth ride...
Last Edit: Oct 14, 2016 22:03:47 GMT -5 by Stinger
Post by Matt Culpepper on Jan 25, 2009 0:04:16 GMT -5
If there's a tech article you guys want written shoot me a pm. We have a bunch of tech articles to do, but there isn't a specific order. Alot of people have asked about one on nitrous, which is topping the list.
Post by bobbarker on Sept 29, 2009 11:25:13 GMT -5
How about a tech article on swapping the VAM to a different/better air meter like MAF or speed density? I've seen bits and pieces of how to's show up in a few threads but nothing from start to finish and everything in between.
any more info that is in a tech page type set up would be very helpfull... I've been all over the net trying to find a swap guide, or other's that have done it and so far here has the only people who have swapped to another set up!
Post by bobbarker on Sept 30, 2009 12:00:54 GMT -5
I remember reading in a few different threads about how to do different parts of the swaps but I can't remember ever reading something that included all of the steps involved in swapping to any other kind of stand alone system.
Hey Stinger.. you have several wiring swap / re-pinning articles, but I don't see one about upgrading to an LA3 from an earlier processor. Any chance of that? I remember there used to be one on GT350R's website, but it's long gone..
Oh, and I haven't been able to find a good writeup on disassembly / reassembly of a a T3 turbo with a 4 piece carbon seal. That would probably be pretty popular.
Last Edit: Feb 24, 2010 2:07:09 GMT -5 by tripice351