Hi,

I've just putted a new GMPP Crate engine in my car, the 350 HO deluxe and I have rebuilded my 700R4 tranny.

The problem is that from the factory my Torque converter lock-up was controlled by a vaccum switch and mine is broken and no good anymore and this part is discontinuated by GM.

So the guy that rebuilt my tranny has putted the lock-up direct so right now on 3rd and 4th gear, my lock-up is ALWAYS ON, the only way to shut it off is to go to 2nd gear or apply brake.

The big problem with that is that i have no power at all on 4th gear since the torque converter is locked, and ever my kickdown to 3rd gear is not really powerful since the lock-up is also engage at this gear..... the only real power that I can get is on 2nd or on 4th and 3rd IF I hold the brake a bit to disengage the lock up.

The question is, Is there's a way to fix that, to make it work normal like before???

BTW, i don't know why, but my new engine only pump 10psi of vaccum and my old 305 was pumping 20 so perhaps it's gonna be hard to make it worked with a vaccum switch again......

I think they must have other people who put the same engine as me in their camaro with the same tranny and managed to make Torque Converter Lock work normaly.

If u guys can give me help about that, it will be apreciated.

Tanks
David

 

Try a 14014519 vacuum switch. Idle vacuum shouldn't make much difference to the lockup operation since your vacuum switch should be on a source of ported vacuum, I believe.

 

[QUOTE]Originally posted by Apeiron
[B]Try a 14014519 vacuum switch.


I've ordered the part today at my Gm Dealer. In the system that part was originaly for a 82-83 Camaro with TH-200 tranny, do u thing it's gonna fit anyway???

 

I'm pretty sure it will work. What was the P/N for the original switch that's discontinued?

 

I dunno

 

I've receive the switch today, as u can see, it seems to be the same thing.....


I just hope that it's gonna open/close at the same vaccum pressure level as the old one. (I just hope it's not gonna need more psi to make it work)

BTW i've checked the P/N # for my old one and there was one number that i was not sure if it was a 1 or a 4 so here it is :

14073467 or
14073167

Anyway I will give news if it's gonna works..... tanks