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Recently bought a factory Carb 83 Trans AM, it has a 700r4 that i assume is factory???
My question is how does the lock-up work for that set-up??? What controls it?
Car is not stock and has a slightly built 700r4 with 3000 stall "lock-up" converter[part number confirmed lock-up]. Engine/carb are also not factory but still carb SBC with mech fuel pump.
I plan to do all fluids/filters and may adjust the governor shift points later. Add a better add-on cooler and while i have the pan off, I'll put an alum with drainplug type back on.
Thx for any relevant info, got tired of digging thru old threads that mostly ask about non stock carb cars n making the 700r4 lock-up work. This car i assume has it in some form from the factory. MY TPI cars were off the computer but idk how this factory carb cars does it???
Relies on input from various sensors including the TPS. If it no longer has the factory ccc-qjet carb the ECM won't receive the input it needs to command TCC lock up.
Relies on input from various sensors including the TPS. If it no longer has the factory ccc-qjet carb the ECM won't receive the input it needs to command TCC lock up.
Thanks! Figured it was something like that and may no longer be possible for OEM "lock up" to work with the things they changed. But for all i knew it worked off the speed-O. Still tho not had a chance to fully investigate the car(climb around under much) and see if they used some other way to "lock up" the converter.
83 Trans AM, it has a 700r4 that i assume is factory
Most likely.
Engine/carb are also not factory
Odds are it'll NEVER work without further intervention then.
with mech fuel pump
Kind of irrelevant.
The factory's logic can be somewhat replicated with an adjustable vacuum switch, the transmission's existing wiring which has an output that tells that it's in 4th gear, and a relay. The trans obviously won't go into 4th except at high enough road speeds and low enough vacuum, and the vacuum switch will keep it from locking up until the vac goes even higher than that. It's a fairly simple circuit. Somebody used to sell it as a kit that was said to work well enough, not sure who it was or if they still do.
Odds are it'll NEVER work without further intervention then.
Kind of irrelevant.
The factory's logic can be somewhat replicated with an adjustable vacuum switch, the transmission's existing wiring which has an output that tells that it's in 4th gear, and a relay. The trans obviously won't go into 4th except at high enough road speeds and low enough vacuum, and the vacuum switch will keep it from locking up until the vac goes even higher than that. It's a fairly simple circuit. Somebody used to sell it as a kit that was said to work well enough, not sure who it was or if they still do.
Mech fuel pumps help tell readers, it's not an EFI car. So very relevant since I know my 85 TA EFI electric fuel pump car controls the lock-up different.
There are multiple non-factory ways to control "lock up"
As i said the car has not been fully inspected, it goes into OD and i don't know fully yet what the builder did as it changed hands with two of his children.
Gonna have to check my settings, thought i had you on the ignore list.[Fixed do now]
The whole factory logic that controls the lockup is really really crude, not hard to replicate if you hook up to the same things the factory did. I think you'll be able to get it done, one way or another. And yes there are "multiple ways", butt, some are AHELLUVALOT better than others. The factory logic isn't flawless butt most of the "alternatives" are worse. People have reported "hunting" in and out of lockup, not coming out of lockup at a stop, etc. Wouldn't quite do to end up with that sort of crap.
https://www.thirdgen.org/torqueswitch/
if shorting the aldl locks it up, "they" used the factory wiring, in part.
If tapping the brake unlocks it, they did it fancy.
Since a switch can be threaded into the third or fourth gear circuit to act as on/off, they may have done it with one of those.
The non-ECM method used by the factory (diesel, early 80s Canadian models) may have been used.
Trace your wires and take notes; you'll figure it out.
Look up transgo 700-LU. That may be the solution to your lack of lockup. I have this kit in my 700r4. It causes lockup to occur with the 3/4 shift hydraulically!
I own a 1984 Trans AM built for the Canadian market. Thus the car has a QJ & a 700R4 & no ecm. Everything works.
As per any info thst u require, I cannot help. there must be a module for the 700R4 that in old school vs an electronic shift & lockup.
my 85 TA EFI electric fuel pump car controls the lock-up different.
Actually, the CCC Carb model would engage lock up the same way as the EFI model; the ECM grounds the lock up solenoid in the trans in either case. So....you need to confirm IF that ground signal is absent, if the converter is not locking, which should be an easy test. If it isn't grounding, then you'll need to work your way back to the ECM to see why it's not grounding. Do you have access to an old OBD I scan tool that you could read a data stream with? That'd help a lot.
Why are people talking about Canadian cars in this thread?
Because CA export cars in those years didn't have an ECM, therefore no ground being applied by an ECM, therefore whatever the factory did to make them work, will work in any car without an ECM.
Pretty sure it involved a vacuum switch, a connection to the 4th gear contact coming out of the transmission, a relay, and a hookup to the brake light switch.
He didn't. He said his car was no longer computer-controlled. Without the inputs from the TPS, dist, etc. the ECM flounders in stuuuupidity. He needs a non-ECM-based means of controlling his lockup.
He didn't. He said his car was no longer computer-controlled. Without the inputs from the TPS, dist, etc. the ECM flounders in stuuuupidity. He needs a non-ECM-based means of controlling his lockup.
If that's true, I agree. If the parts are still in the car, he could do some diag and make it work.
the TCC lock up used it's own brake switch which would be normally closed whereas the brake light switch would be normally open. I have, in the past, had to take one of these switches apart to 'repair' it to get the lock up working again. correct me if I'm wrong.
FWIW: My 84 carbureted Camaro was non-computerized. TCC lockup was factory designed to work via the brake switch, vacuum switch and the 4th gear applied switch (in the transmission).
By way of comparison, the 82 Monte Carlo in the "fleet" was done the same way.
I've duplicated that in the current hot rodded 82/86 chassis.
FWIW: My 84 carbureted Camaro was non-computerized. TCC lockup was factory designed to work via the brake switch, vacuum switch and the 4th gear applied switch (in the transmission).
By way of comparison, the 82 Monte Carlo in the "fleet" was done the same way.
I've duplicated that in the current hot rodded 82/86 chassis.
Interesting and one could do it that way.
I perused the wiring diagrams for a vin H '86 and they show a NC switch going to the TCC and a NO switch for the stops. The NC switch had two outputs, the second looks to have gone to the cruise.
