I'm stumped on this one. My trans doesn't want to unlock. I have learned that 700R4s lock in 2,3,4 gear, and it will do it at any speed. Even 5 MPH. I've installed a switch to unlock it. disconnecting the ground on the left side of the tranny housing.
I understand it could be considered a performance booster however when my consern is that it's a pain in the but to drive, Plus when I pulled the dip stick the fluid smelled a little burnt. Now, when I drive it, it never drive in OD without the TC locked in. The lock up Solenoid has recently been replaced. People are telling me it could be the PROM. any other ideas/ solutions.
I'd like to leave the switch installed for racinging. But I'd like it to be normal and the switch to force lock-up. I'd greatly appriciate any help. :hail:

Thanks.

Vinny

 

Are you sure it's not unlocking? With your switches set to "normal" operation, go for a drive. On a highway, at 50 mph or above, with light throttle, in OD, keep your right foot constant on the gas. Tap the brake lightly with your left foot- enough for the brake light to turn on.. maybe about 1/4 inch. Your RPM's should jump up a few hundred as the TCC unlocks, sensing the brake light. If the rpm's don't jump up, your TCC was never locked to begin with.

The main performance boost is from a TCC that's forced to lock as soon as you enter 2nd gear. A TCC with delayed lockup only makes the car feel more powerful. This is due to the increased RPM, which usually brings the motor closer to it's powerband (RPM range where the cam produces the most power).

Have you removed the computer or something? I think I've misunderstood your question, but it seems like you have one switch to unlock the TCC and one switch to lock it.

 

well when the I have the switch disconnecting the ground wire for the connector on the left side of the trans. This basicly disconnects the whole plug.
When the switch completeing the circuit the TC locks in second gear. now, that said when you are driving and press the break, it does unlock on it's own. the problem is driving in any gear above 2nd I'll say I'm driving through town in O.D. at 25 MPH. the TC locks. this causes the car to buck/bog, and is very anoying. so, now it's bucking and boging, you pull the shifter to drive(or second) It will put you through the windshield.
If I understand correctly, it shouldn't lock entil 45 MPH and above. Is this correct.
The TC in my car will lock at 10 MPH ( and below if you let it) in any gear above second. again when you step on the break it unlocks but locked at 10 MPH is alomost undriveable. any thoughts?

 

Explain exactly how your switch is hooked up. The correct way is to cut the ground wire going to the tranny and hook the switch to both sides of the cut wire. If you just hook the switch to the wire going into the tranny, and the other to a ground--you will get the problems you are telling us. Grounding that wire will force a lock-up in 2nd gear and up. If you do have it hooked up the correct way, the ecm may be the problem--the ecm grounds and ungrounds that wire to control the lock-up.

 

Yes I've cut the ground wire at the transmission and placed a switch in that line. This is how I have been unlocking the TC.



Now if it is the ECM, or Prom. will a Hyper tech chip correct the problem? some Hypertech chips piggie-backed the OEM prom. some directly replaced the OEM prom. this is on a 1985 Trans am with 305 TPI.

Vinny

 

Remove the power going to the transmission completely (this can be done at the brake light switch), and give it a try. If is still locks up, you don't have an electrical problem. If not, then continue down the electrical circuit fault isolation route.

 

When you step on the brake pedel, the TC unlocks, Thus the Circuit must be good from Brake bedel down.
What would be the next thing in the line UP. I'm guessing ECM.

Anyone know about the Hypertech chip? Piggie-backed or not for 85 TA TPI

 

For a little more than the cost of a hypertech chip you could buy a prom burner, tunercat and a few flash proms.

In the chip there are basically four constants and four tables that you would want to adjust.

Constants:
mph to lock in lower gears (usually 40mph)
mph to unlock in lower gears (usually 38mph)
mph to lock in 4th (usually 40mph)
mph to unlock in 4th (usually 38 mph)
(these are stock figures on AUJP bin)

Tables:
You really have no need to mess with the four tables as the factory settings work fine. They deal with %tps and mph to lock and unlock.

There's also an auto lock speed threshhold that should be set to 75 mph. Has any body ever messed with your PROM cause it sounds like some of these constants have been messed with?

 

To the best of my knowledge, no. The previous owner is a good friend of mine, and the owner before that is tech stupid. This all worked normally for about 6 month that my friend owned the car. And he only drove it local about 400 miles /year. So he just unplugged it and never ran in O.D. I’m driving the car almost daily. So I would like it to work normally again.
I did call Hypertech and found that the 85 prom is a direct replacement not a piggy-back.
Also it’s $108 through summit for the street master. I know the Thermomaster is a much better setup however I’m just looking to fix the tranny not tweak the car. So from a professional stand point what is your opinion. I’m an amateur at automatic transmissions.

 

Here's the problem with Hypertech chips and the reason I don't like them. All they do in the chip is adjust the fan on/off temps and give it WAY TOO MUCH spark advance in the upper rpms. This causes detonation which causes the knock sensor to retard the timing about 10 degrees which actually slows your car down.
Then they give you this bull about a 160 degree thermostat which is the real reason for a horsepower pickup if you don't hit the knock sensor first.
You could just put a 160 stat in and put your fan on a manual switch and you would have a better setup than a hypertech chip.
If you don't want to burn your own (which is actually easier than signing on to the internet which you just did) get a new stock chip from GM for your application.
If you don't believe me go over to the DIY PROM board and type "Hypertech" in the search box. There should be plenty of posts for you to read and hopefully it will change your mind about buying a Hyperjunk chip.
Let us know how you make out.

-IROCZ88

 

Thouse are good points. I'm actualy a technical guy, Computer smart. O.K. all of thease are good points with the knock sensor.
Now, where would I get all the pieces to the puzzel and for how much cash are we talking.
The reason I was thinking hypertech is because I figured it would be cheaper than a new stock prom. I've never got around to pricing a stock prom. Acording to summit Racing's Tech line the Hypertech chips is one of the best for the F-Body meaning better that JET's version etc.
Thanks for all the help allready. and any in the future.

Vinny

 

Here is what I use:

Pocket Programmer $150
Tunercat + DEF 90
Craig Moates ZIF 40
3 Flash Proms 15

Thats all you need for adjusting constants and switches in the chip. I also have a laptop and Datamaster for recording data from my car but you don't need that until you start adjusting the VE tables and spark curve.

It seems like a lot more money than just buying a premade chip, but once you have this equipment the possibilties are endless and you'll be much happier and satisfied.

Read this article and it will tell you where to get this stuff.
www.thirdgen.org/newdesign/tech/promintro.shtml

 

I was just reading the site dealing with DYI prom burning, I was thinking of an other advantage, My 2000 S.10 with a speed limiter of 96 MPH. with 4.3/ L60E i think, and 308:1 rear . In this config. she turns a rather impressive 15.56 ET in the 1/4 mile. proble is interstate driving she turns 95 in O.D. at 2600 RPM. with this prommer I might be able to raise the bar of the 96 MPH limiter.

is this ture. I know the programmer III for your favorite manufacture advertises it can raise the speed limiter.

 

LOL!! I've heard good things about there programmers because you can adjust what you want. It's just there chips where they rip you off.
If they say it can do that than it must be true. I have no experience with it myself.

 

People I know who have the programmer realy like it. realy like it's ease of changing settings and said it did raise the speed limiter. this was not in an S-10 pickup though. The down is, once the programmer is used I guess it remembers some sort of ID code emmited from the ecm once that is used you can only use the programmer III in that vehicle. At least that's what I've been told.
Tell you what. I'm liking the programmer idea. but for now I'm going to look into getting a stock replacement PROM. Performance mods wil be after I get the motor rebuilt.

Thanks again for keeping this sheep from following the wrong herd.

I'll keep you posted.

THanks,
Vinny

 

The problem is the single disc clutch in 700R4 TC's wil not take that kind of abuse. It will probably burn up very quickly.

 

in further research, I don't have an electronic Speedometer. which means my TC must at some place be connected to the TPS. That at least according to the code scanner is working fine. I had the prom out today getting the number off of it for pricing at the dealer ship. not too bad only ~$65.00.
But seeing the prom out of the computer really makes me want a pocket programmer, and a few EEPROMs. on the 85 the EPROM plugs right in to a socket. not daughter card or nothing.
Any how If TPS is good, and it seems like it. it has to be the prom. I'm out of ideas. but it's totally ignoring the speed variables . I had it locked in O.D today at 10 MPH bucking like a mule.

 

Guess what All. I replaced my Eprom today with a new stock one. Fixe everything. She is shifting solid with correct TCC adjustment, and also locking correctly. Hope this post will help someone else with a simular problem.

P.S. I am looking in to building a 350, Keepint the TPI. so in the future plans is a pocket programmer. but Now i can sleep at night knowing the it is working correctly.

Thanks for all the help

 

If you notice the torque converter is unlocked at WOT? That is the way it should be, unlocked at WOT. Glad you fixed it, now change the fluid (all of it) to a good quality fluid and install the Trans-Go Shift kit.

 

It works great, Unlock at WOT doesn't lock in over drive until about 43 MPH etc. Love it. I do need to change the fluid/Filter. it's a little burnt from the switch. Not sure I want a shift kit though. Is'n't a trans pack better???