MTPFI-MAF

Ok I am going to be swaping out my T-5 in favor of a Pro Built Automatics 700R4 and I want to take lock up control away form the ECM (for my own pig headed reasons)
Well anyways there are a lot of choices on how to do it, and I don’t want to flip a toggle Switch everytime I want the converter to lock up. So that leaves me with several options.

TCI Lock up Kit (http://www.tciauto.com/instructions/376600_inst.htm) $76.00

B&M Lock up Kit (http://www.bmracing.com/products/kit...ockupCont.html) $160.00

Painless Wiring Lock Up Kit (http://painlesswiring.com/fiacc.htm) $125.00

Ok Here is what I want. I want the TC to lock up normally which I hear that the TCI, Painless wiring, Vacum Kits do, also they would be wired to the brake switch so when the brake is applied it unlocks the Converter, The problem I see which I am pretty sure I am not fully understand this is that the vacuum switch use a vacuum reference to tell the system when to lock up. Well on a modified Engine is the vacuum reference going to be correct Or Not. Or does each one of the Kits above have theire own application dependent on the type of driving done.

I have also been told that I can purchase the Vacuum Switch form GM and wire everything accordling.

Some one Help cause I need to know the correct way to do This.

And Yes I used the search function. Didn’t give a direct answer

Kingtal0n

<b>I have also been told that I can purchase the Vacuum Switch form GM and wire everything accordling.
</b>

I think Dana recommends this method... From what I understand GM actually makes a vacuum switch that will LOCK after certain vacuum, and UNLOCK when it goes back below that vacuum.

I thought about it for a while, then realized that with such a high stall you can see lots of vacuum and still be 1200-1500 RPMS away from your "lockup RPM" causing the converter clutch to come on and burn as it pulls the motor's RPM down. So what stall do you plan on running?

engine mods, yes a large cam will not want to lockup nearly as often or as early as a small-ish cam. but beleive it or not it would probably be better off with one of those lockup switches since it wouldnt be trying to lockup unless you really were cruising...

I personally still use a switch in the console. Im used to it now, I switch it on when i hit 3rd and let it stay on in 4th like it should. Unlock it before i hit the throttle too hard... works fine.

the GEN7 DFI has a converter lockup switch built into the ECU. It has options like lockup delay, converter performance mode, etc.. some silly stuff I was thinking of giving Gen7 a try (for other reasons) but this option is a plus. what ECU are you running / planning on running?

MTPFI-MAF

I am going to go with Probally a Precision Industries "Vigilante" 9.5" probally around a 2600-2800 stall

as for the GEN7 DFI it has the same options once you get into prom burning But I don't want the ecm to control the tranny.

Have you looked into using a stock ECM and modding it to do what ya need. IMO it is a lot better than the GEN7 DFI for once you learn source code you pretty much have total control over everything and can and almost any thing IMO

not sure how I am going to do the Lock up YET.

Kingtal0n

YEs Ive done several stock ECM setups. the Gen7 has features that I require, such as nitrous control and boost sensitivity where the stock ECM does not.... I know about the syclone code but it still doesnt have the real time tunability that the Gen7 does.

my3rdgen

I rewired mine because I went non-ecm when I installed my 355. I had to buy a new 4rth gear psi switch because mine came stock with a NC switch. I got the NO switch for around $10.00 from GM, and also bought the plug adapter for a TH400 that fits into the case of the tranny $3.00 (gives you a single spade terminal to hook a wire to). I then wired power from a switched ignition source to the brake switch that kills the loc-up when the brakes are applied. This will lock the TC up only when the tranny is in 4rth gear, and will do it without flipping a switch.

Total cost for me was a whopping $13.00. If you used your existing plug on the tranny, and your tranny already has a NO switch, the cost will be free.

IROCU69

iTrader: (1)

I found a cheaper kit ( I was thinking about doing the same thing you are) at www.tpiperformance.com they have a kit on sale for $69.50 However I think I'm going to do what my3rdgen did as soon as I hear back from him on how to do it myself. Gets the job done and at a lot cheaper price.

-Mike
85 Sport Coupe 358ci

MTPFI-MAF

If ya would please post what ya do and how ya do it.

thanks

IROCU69

iTrader: (1)

Yes that info would be very helpful for me too. As CarCraft Summer Nationals is this coming weekend and my car still doesnt drive well. I need to take out my TH350 and put in the 700R4 and get it driving right. Not to mention finish making my ram-air hood. To much to do and not enough time.

-Mike

my3rdgen

Sorry it took me so long to get back to you. I have had two bad days in a row and didn't check my email. If you want to know how I did the convertion, read the post below for more detail. I will try to explain as best as I can here what I did. It is a common way to wire up the lock up and a lot of people on this board have done it this way.

First you must read this post.

https://www.thirdgen.org/techbb2/sho...hreadid=230910

Remove the pan and fluid filter. And rewire the solenoid so that the wire from the solenoid goes to one side of the NO PSI switch for the 4th gear switch. Hook another wire from the other 4rth gear switch termenal to the plug that goes through the case. Wire your switched (ignition) power through the brake switch on the brake pedal (for the original lock up cut-out) and to the plug on the tranny.

What this does is when the car is running, power runs through the brake switch (unless the brake is depressed) to the tranny and to the NO 4th gear PSI switch. When the treanny shifts into 4rth gear, it puts PSI on that switch and closes it locking up the TC. When the tranny downshifts or the brake is pressed the voltage to the plug on the tranny is interupted and the TC unlocks.

Hope this helps, if you need help just yell.

EDIT: I used my stock in-tranny wiring harness to get this done. I didn't have to cut it up except where I connected it to the TH400 tranny plug. Also if your solenoid has 2 wires just ground the red one so that you can use the old wires without cutting them. They are a special wire that hold up in the oil and heat.

I am in a hurry right now or I would right you a book and I am typing all this off the top of my head from memory. LOL! I hope I have left you with no missunderstanding or bad information. Ask questions if needed there are no wrong questions and I will respond as quickly as I can.

Good luck.

my3rdgen

I have to get under the car to change the pan gasket Sunday anyway, so I will look to see how I wired the dang thing up. It is bad of me to not remember how I did it, I usually don't forget stuff like this. I will take some pics too. I just can't remember if my new psi switch had one or two connectors on it. That would change how you wire it. Weather you have a one or two wire solenoid will also change how you wire it up.

vernw

iTrader: (2)

I used the TCI kit with great success on my old Suburban 454HO Holley Commander 950 MPFI setup, and it should work the same on any 700R4. Including their vacuum lock up kit.

FWIW - what the vacuum kit does is UNLOCK the converter by removing the ground connection when the vacuum drops below a certain value (like when you accelerate hard to pass someone or go up a steep hill) and then locks it back up again when you go back to a "normal" throttle. The point where it does this is also adjustable on the TCI vacuum kit so you can set it where you want.

Hope this helps. Good Luck!


- Vern

IROCU69

iTrader: (1)

yes if you could post pictures that would be sweet. I actually have my trans out of the car and sitting in the garage so doing this work to it should be easy. I just hope the local GM dealer has those parts in stock. Now let me know if this is right. I need the following parts TH400 connector pin PN 24205373 and NO switch PN 8642473. Is the part number for the switch somewhere on it were it wont wear off? I would like to try and find out which switch I have... however since its out of a 86 TA I'm betting that its a NC switch. In any case I may drop the pan off of it tonight and take a peek.

-Mike

my3rdgen

I will hope to get the pics posted by Tues or Wed. I am sorry for the delay. I am going through a custody battle (I'm going to win), refinancing my home, and taking the four little ones to the dentist tomorrow.

Get a cheep Ohm Meter or a continuity tester, and find the fourth gear switch from the diagram on the post I linked. If your switch has one termenal (I think they all do) then put one probe from the tester on the termenal, of the psi switch and one to the tranny case. If the tester reads 0 or the light comes on it is a NC switch.

Do you have a one or two wire solenoid?

I got to go the Ol' Lady is B1tchen.

Apeiron

You don't need that connector if you still have the factory harness. Some people use it because it's a little more convenient to use a quick-disconnect terminal than it is to try to find a mating 4 pin connector.

my3rdgen

Correct, it isn't needed, I used it because I didn't want to splice into my harness. I want to leave it alone in case I do ever want to use the ECM again. Just leaving my options open.

IROCU69

iTrader: (1)

Spose I should give a little background on my car. It was originally a V6 85 Sport Coupe. I've swapped the engine oh about 5 times switching between a stock 305, modified 305, 69 355 (12.5:1), and then finally to a 69 358 (10.25:1). The stock V6 harness is long gone along with the Th200R4 and 2.8 MPFI that was mated to it. As far as factory harness goes... I've got the basics that were left in the dash and the alternator and ignition wiring. I've been running a TH350 I pulled from a Olds Cutlass Supreme. However not having OD has been a real pain on the highways and I want my OD back. So I bought a 86 TA 700R4 off my brother when he didnt use it to build a TA parts car he had bought. So thats the story in a nut shell.

-Mike

IROCU69

iTrader: (1)

I pulled my pan this morning (didnt have time to do it before) and took some pictures because I'm not to familiar with it compared to the drawing that was on the other thread. Looks like I have a 2 wire solenoid and those seem to be the only two wires going to the 4 port plug. looks like the only pins connected are pins A and D. I cant visually see anything else in there as far as switches

Heres the full view shot with the pan and filter removed

"took out picture because it didnt work"

-Mike

Apeiron

Doesn't work either.

IROCU69

iTrader: (1)

Ok here this has to work...

copy and paste

www.geocities.com/irocu26/fullview

If this doesnt work I dont know what to do.

-Mike

Apeiron

Yup, no switches on that thing.

IROCU69

iTrader: (1)

So what do I need to do? Do I still need to buy the NO switch and then the question is were do I put it in there?

I'm betting I just need to send power to that solenoid through the red lead (yellow lead in picture), pin A and then ground it through pin D to turn the TC lock up on. Which could be done with a manual switch externally but I'd rather not have to worry about yet another switch to turn on and off. So a little help please.

Thanks, Mike

Apeiron

Buy the switch and put it into the valvebody where the 4th gear clutch switch is in the diagram. You'll have to take the plug out first, of course.

<img src="http://www3.telus.net/~crussel/tcc_wiring.gif">

There are still a number of ways you could actually wire it. The way I'd probably do it would be to get a 8642473 single terminal NO switch, run a wire to pin B on the connector, and then join the wires to pins B and D together outside the transmission.

Apeiron

Actually I changed my mind. Whatever vehicle that thing came out of, it doesn't have the right wiring for an F body so why not butcher it. I'd replace the connector in the case with the single terminal 24205373 connector, and run a wire from it to one side of the solenoid, and then from the solenoid to the terminal on the 8642473 switch.

my3rdgen

Apeiron, thanx for helping him out. I havn't gotten time to get on the computer or out into the garage this past week.

Apeiron

One of these days when I have a 700R4 apart I'm going to take pictures and make a tech article.

my3rdgen

You might want to get a new solenoid for a 1987 TransAm because mine (87) had a two wire solenoid with a short red wire and a long black one. The short red wire has the connector on it needed to hook it up to the psi switch and the black wire is long enough to get up to the termenal in the case. This way you won't have to figure out how you are going to attatch the wire to the psi switch.