Hi all,

here's the deal. I've got this '83 Z28 with a 700R4. When I bought it, it had a holley carb installed, most of the emissions equipment removed, etc. It does still have the stock distributor though. I know everyone says that's bad...I just didn't realize it until lately (after I stopped driving it) and truth-be-told it was running alright for an automatic and getting 20 mpg on the freeway.

I'm removing the A/C and will probably get a vacuum advance (mechanical) HEI for it. Eventually I would like to swap it over to a manual tranny too.

So my question is this: Can I utilize the stock computer to controll only the lock up torque converter for the present (until I eventually swap to manual?). I'm looking to do this cheap. I don't want to spend a bunch of money on a TCC kit that I won't use very long (assuming I will be swapping to manual soon).

What does the computer read (input) to decide when to lock up? Can this be done fairly simply?

A little help would be appreciated.

thanks
Clem

 

Pushing this back up for ya I got the same question... also what if you just run a non-cc carb but plan on keeping the distributor and tcc for a while? Does the computer have to be all or nothing? (I'm running an '83 LG4.)

 

I guess I could always rig up a manual switch like in the tech article...but that wouldn't be optimum for me (especially since I might be selling the auto car soon...would like to keep it though). I'd prefer to find out what the computer requires to retain this function. If it is fairly stand-alone it shouldn't be a huge problem.

Could anyone tell me what the computer reads as input to determine when to lock/unlock the converter?

The computer doesn't know how fast the car is going in '83 (IIRC...no VSS). I don't think it even knows what gear the car is in...or maybe that's it. Does it know when the car is in OD and lock it up under certain vacuum conditions?

Please help,
Clem

 

There is a VSS. It's a yellow box thing that bolts on the back of the instrument cluster, it "looks" (literally) at the speedo piece that spins.

The ECM needs to know the vacuum, the gear the trans is in, and the vehicle speed. It might also need the coolant temp. I have no idea whether it would function correctly without distributor pulses since it might think the engine isn't running and therefore wouldn't need the clutch.

 

Bottom line, you can't use a factory computer to control lockup. Without the distributor pulses, the computer will never think the motor is running, therefore no lockup. Even with the distributor input, lockup is one of the first things the computer stops doing when there is problems with other sensors.

All you need to do is spend 5 minutes splicing a switch from the "F" wire on your ALDL link to ground. You switch it, it locks up.

But get the right distributor first.

 

You say bottom line it won't work without the distributor pulses. Thanks for that info. I'm assuming though that if you wire up a switch, it will work even without the distributor...right? Sounds like what you're saying, and that makes sense.

I guess I'll just have to go that route until I can ditch this pos slushbox.

thanks for the info.
Clem

P.S. It sounds like you may have some knowledge of this system. Check out this thread:
https://www.thirdgen.org/techbb2/sho...0&goto=newpost

and let me know if you can offer any advice or insight. thanks!

 

The computer is pretty much all or nothing. There is a stand alone TCC module that is used on older cars that are retrofitted to overdrive automatics. I don't remember who makes it, but you should be able to get it from Summit, or Jegs. It works off a VSS that comes with it and locks up after a certain speed.

 

I know about the kits...I was just going to see if there was an easier [edit: I meant cheaper) way.


Just some background on my car. For some reason, even though the carb had been swapped out, everything else worked OK. The TPS (and possibly MCS) are just removed from the old carb and still plugged in laying on the intake manifold. Strange...but it worked and was quite dependable for the 2 years that I drove it. Strange huh?

 

Cool!

But fix the A/C as the next person that wants it may pass your car by because it ain't there. A/C is a great selling feature and only uses maybe 5 hp to turn.

 

I wouldn't have removed any of this stuff. It was all started by previous owners. If I keep it it will most likely become a track car (open track/road race). I'm keeping all the parts, but I don't have the money to fix the A/C. The lack of A/C is not what's going to devalue this car if someone wants it. If someone passes this car by, that's fine by me because I don't really want it gone (I'm humoring the wife by "trying" to sell it ).

thanks
Clem

 

man i don't know how it was hooked up but my car wouldn't even run with out the new distributor. i haven't done the tcc lock up yet but i will soon. and that is the only way i know to do it.

 

You need inputs the ECM for lockup to work:

park / neutral switch

VSS

TPS

temp.

As for distributor pulses, I'm sure it can be faked somehow.

I'm not sure on the 700 if you have a 4th gear pressure switch necessary for lockup (a'la 200-4R) but that would need to be working too.

There's really no reason for the lockup not to work. Theoretically you can use a 79 or so Q-jet w/ TPS but no M/C solenoid to do the TPS, or look for an aftermarket TPS. I too would prefer not to run the aftermarket lockup "kits."