I am having torque convertor issues. I put a car together from a mess of parts. It was a TPI Trans Am with no motor or harness/ECM. Got a new motor, rebuilt tranny , new convertor used factory harness, installed all myself. Long story short, the torque convertor won't lock-up, unless I use the under dash "jumper wire" trick, then she really locks up. I'm looking to get this to function like its supposed to. Any suggestions would be greatly appreciated. The car is great otherwise and no codes are presently appearing.

 

If you used a five speed manual harness or ecm, it won't control the lockup function. As far as the ecm, check the broadcast code on the prom chip to see if it's for manual or auto car.

 

I see we're still on speaking terms after the Hood Blister Drama !
Thanks for the info, I will pull the ECM/Prom tomorrow and check the codes. I plan on having a new chip(burned) would that correct the problem without having to check the codes? Maybe I should check anyway . Thanks for your Input.

 

No worries dude. Mud washes off after the slinging is over with! I figure if you can actually lock it up manually, it has to be something with the ecm or harness provisions.

 

Yeah, that sounds logical. I'll let you know what I come up with on the codes. I'm hoping you are right.

 

Pulled the ECM today. Here is what I found.

16069300.............Delco........... 16055375 ....... 16055376
27C256/5DBB..........ACXS ............8723..................8720
D 501AP
U711009SX


Haven't been able to find all the info I need to crack to codes.
Any help is appreciated.

 

I forgot to mention that you can find the prom broadcast code info in the FAQ section on this site. The part# of your prom isn't in there, but the broadcast code (ACXS) says the prom is for an 87 Firebird 5.0 Auto Trans. (MD8) Fed. 2.73 (GU2). So if that info is correct, then the prom you have should be for an auto trans. The only other thing I can figure is maybe there's a broken or missing wire in the four prong plug that goes into the trans, or the ecm is faulty and isn't grounding the lockup feature? You could always send a pm to Traxion or Anesthes since both of those guys are prom/ecm gurus. Anyone else have any ideas?

 

First off.

Get a wiring diagram and see how they wired the TCC switch in the car.

than figure out what its bypassing in the tranny.

Bad gear switch could be overirdden by a manula switch to apply lockup.

I would have to guess a bad 3rd or 4th gear switch and /or wiring issue

later
Jeremy

 

Thanks for looking into it Pat, I did use the FAQ section to see the codes, but as you know it wasn't there. I'm gonna look into the short harness first, the one that 4 plug that goes to the tranny, I think it can be disconnected/unplugged by the Distributor. I'll change it out and go from there.

 

Jeremy, This car came with the tranny still in it, but no motor. Purchased from a friend. After the donor harness/ECM and new engine were installed I noticed the tranny slipping right away.
My first thought was to change the tranny, and since I had a fresh rebuild in the shop, I dropped it it with a rebuilt convertor for good measure. Guess what, same problem, slippage. My next idea(should have been my first) was to jump the data box with a short wire to lock up the convertor. It worked!...So this is were I am stuck, how to loose the jumper wire and function off the harness. I'm not to electrically inclined, so if you have any other suggestions, please spell them out for me! I am under the impression that driving around under total lockup is not that good for the tranny. I could live with a switch if its the simplest way to go?