First off, I've got a 85 Z28 w/ LG69 305, Holley 4160 w/ e-choke, MSD HEI Distributor, and DynoMax exhaust. After putting on the Holley and MSD, my computer shut off, I guess because it didn't have anything to do . The car is running great now, but the only problem is my torque converter does not lock up. I don't need it to lock much, just for those long drives on the highway so I can save some gas. The TC bring my cruising RPM's down like 500-600, so that make a difference. I know there is a way to wire a switch into the computer to lock it, but my computer is dead. Is there another way to wire a switch up w/o the computer. I don't wanna spend $129.99 on a retrofit kit. Any advice is appreciated.

 

Do it the same way, pins A and F on the ALDL port, as long as you haven't hacked up the factory harness.

 

There is a tech write up on this already(under carb I think) plus I just bought a TCI automatic lockup for $78.

 

Get a vacuum activated switch from GM, I can find the part number if needed, hook up a 12v igntion source, then to a in line resistor to drop the voltage to 5v, then to the switch, on the other terminal run it to the A terminal on the 4 pin connector at the trans, inside the pan, there should be a red wire(from the A terminal) that goes to the TCC solenoid, then a black wire to a pressure switch. Hook manifold vaccum to the vacuum switch and thats it. It will lock up in 2nd, 3rd and 4th. When you are cruising and have high vaccum your convertor will lock up, when you accelerate it will unlock, and when you go back to cruising, it will lock back up. This is the way Dana told me to do it, I have everything, I just haven't hooked it up. He said they have been doing it this way for years and it's alot easier and cheaper than using a TCI kit or hooking it up to a toggle switch.

Hope this helps.

Jason

 

i do them almost like that but i pull the pan and hook it up to fourth gear pressure switch, that way it only comes in in 4th, also run the vacuum switch, works great...

 

I think you are right about it only locking up in 4th gear now that you mention it, I can't remember for sure now, I'll talk to dana this week and ask him. Sorry if I gave any wrong info.

Jason

 

I'd still use the ECM for timing, and lockup. but thats just me.

-- Joe