I am swapping over from TBI to carb in my 91 camaro, and i have read that my Torque converor will no longer lock up. Why is that? The computor is this hooked up and everything is still in tact just no more injectors or computer operated dist.

 

???

 

No throttle position sensor. That's one of the things the ECM looks for to determine when to lock up the torque converter. I suspect that there are other reasons- like the ECM will be in a fault mode since it basically won't have any communications with a LOT of sensors on the motor once you've conrted to carb and it probably wouldn't allow torque converter lockup even if you somehow "tricked" a TPS signal to the ECM.

 

So what are my options here, i mean as far as getting it to work like it did?

 

1) You can order the kit from Painless with the required wiring and vacuum switch. 2) You can wire it yourself through the brake switch through a vacuum switch to the fourth gear switch for about half the price. The intent either way is to engage the lock up when the tranny is in fourth gear and to disengage whenever the brake pedal is pushed or there is a change in manifold vacuum (throttle change).

If you're not sure you can do a professional wiring job, I'd recommend the kit.

 

do you have to pass emissions where you are?if not,just remove the computer and everything associated with it!everything you need will still work,and the check engine light will always be on.
you're going to need a different fuel pump.
i used the tci lockup kit,76.99 at jegs,didn't hook up the override yet,but the thing works just fine.part#890-376600.
b&m and painless also offer more sophisticated kits at roughly twice the price
Eric B

 

You can order a 4th gear lockup only kit off of ebay for 14.99. It just needs 12 volts and will lockup. It includes everything you need for the job except pan gasket.

 

I've been told that if you leave everything else intact (VSS/ECM) that the TC will still lock up. It's only dependant on the VSS and which gear it's in via the tranny pressure switches and CTS maybe. I might be wrong, but trying first and buying later might be an option

 

Nah, it needs the TPS too.

 

Check this post...notice the reply by evilcartman...

https://www.thirdgen.org/techbb2/sho...ght=TCC+lockup

He's using a differnt tranny, but really should be an issue.

Maybe a quick check at the DIY_Prom forum would tell the tale?

 

Can't answer for the 200C but the 700R4 uses the TPS for lockup in the same way as the vaccuum switch for a mechanical system. When there is a (large enough) change in throttle position it unlocks the converter. The vaccuum switch does this by sensing changes in manifold vaccuum which is also caused by change in throttle position. Both are indicators of changes in engine load. Trickster has posted some diagnostics for the lock up that will definitively answer this.

 

Cool, I'll have to look further into it, I'm getting ready to do the same thing (SBC-carbed with 700R4) and had been searching around (only reason I had that thread).

FWIW, I plan on the vac switch and using the 4rth gear pressure switch for TCC lockup.

 

If you're wiring it yourself you may consider adding a switch to disable the lockup. There are times when it can annoy and sometimes it can cause a slight delay when detent downshifting at cruise. While you're there anyway.

 

if you dont do any of this wiring, can anything bad happen to the tranny?

 

Yes, running an overdrive trans without lockup lets it cruise near its stall speed which increases the slippage in the converter creating more heat. Higher temps can lead to premature failure.

 

cant you run the purple wire from the trans to the brake switch and have that control it?