i have read threads for months now now i think ive read so much that im starting to get confused! is there any one out there that can give me some strait answers on what i can and cant take out to make my car carbed.i also need to know what has to b done and what dont.will this work even though my car has vats or does this not matter? i know that this matter has been coverd many times but i am not making any since of it.
my car is a 92 25th rs 350 someone else has put the eng in it is still tbi dont quite run right that is why i want to go to carb it has headers crap center bolt heads. i have a edlebrock 650 4 brl carb performer intake and a better set of heads dont have spects on them yet gonna run numbers on them tonight. they are older style heads

 

This covers the basics: https://www.thirdgen.org/carbswap

VATS isn't affected if you leave the ECM in place. You can remove the harness that goes from the ECM to the engine compartment without affecting that (or speedometer). If you have a TH700 automatic transmission, you'll have to do something about the torque converter lock-up circuit, which is part of the ECM harness. I'm not clear on the transmission-mounted VSS circuit, perhaps someone else can chime in.

You will need a vacuum/mechanical advance distributor of some sort.

 

you know if i can remove the engine harness and leave the rest and keep the speedo that would be cool. maybe pocket would know.

 

On a 1992 TBI car the entire pass side harness can be removed when swapping to carb.

 

but the harness that is left will it run the speedo and everything else without the engine harness.

 

The speedo is not a part of any of the engine harnesses or underhood harnesses on a 92 - it's an electric speedo with speed sensor at the tranny that plugs into the instrumentation harness.

The driver side harness has all the inputs for the rest of the guages, including tach, water temp, oil pressure. The oil pressure guage is fed by the third wire of the oil pressure sending unit which is just above the oil filter (stock location), the water temp is fed by the sending unit on driver side head between #1 & #3 plugs - tach supplied voltage from the (I think) white wire in the distributor wiring. Volts supplied by the alternator.

I always advise anyone swapping to carb from TBI to just leave the pass side harness alone - get the swap done, and make sure everything works correctly - then remove if desired.

BUT - since the TBI harness is worthless anyways (as in so sellable value to anyone unlike a TPI harness that sells for decent bucks), might as well leave it in place and just cut the leads back, and tuck the harness into the fenderwell where it's unseen. This leaves you a slew of wires that already run from the cabin to the underhood to make use of in the future for things like foglights, exterior lighting, aux fan wiring, etc. I've made alot of use out of mine!

Feel free to PM me with anything if you need help - my 1992 RS has been swapped to a 350 carb for over 2 years now, and I've had everything working properly since.

 

ok this answers alot but can any one help with the trans lockup? im running a 700r4

 

Is the torque converter clutch lock-up part of this transmission harness?

 

Not that I'm aware of - the speedo signal comes from a wire that plugs into the rear of the tailhousing, the lockup is in the 4 wire connector in the side of the main tranny body - I don't remember the two ever 'meeting up'.

There was a sticky somewhere about options for locking the TC, but now I can't find it.

Basically, as I remember - there are several options.

1) leave the ECM connected, and use a toggle connected into the correct ports of the ALDL to manually lock the TC

2) leave the ECM connected and use a vacuum switch to lock the TC using those same ports of the ALDL

3) a combo of 1 & 2

4) Purchase an aftermarket kit that installs into the trans and provides both 1 and 2 (like the TCI kit at Summit which is what I used - about $90)

5) B&M now makes a kit that connects into the existing wiring and controls TC lock based on a user defined speed without having to open up the tranny - about $160

I really wish I could find the sticky - I looked in the carb, tranny, electronics, and engine swap forums with no luck - anyone know what happened to it?

BTW - I went with the TCI kit that installs into the tranny because I had the tranny out anyway at the time of my swap - I had it rebuilt, installed shift kit, servos, and the lock up kit.

 

i am gathering that the easiest way to control the tcc lock up would be to go through the aldl connector.if this is so than does any one know where i can get a pin out for this or a write up

 

also i would like to know the out put pressure on my fuel pump it is a 92 tbi v8 this might aid in buying a regulator

 

That would mean the TCC lock-up harness would come out with the ECM engine harness, meaning you need to either cut that out of the ECM harness, or do one of the stand-alone aftermarket kits.

You mean this one, https://www.thirdgen.org/forums/carb...c-control.html second from the top in this forum?

No, that won't work if you remove the ECM and ECM engine harness.

 

no i dont plan to remove any wiring was gonna stuff it inside the fender incase it is needed down the road

 

well went out and removed the ecm. no speedo. im also using one of the injector wires for the choke. also one of the fuel pump wires to go to my hobbs switch. i believe a couple a more wires to. but i can tell you that i did remove all the wires that i wasnt using for the ecm and sensors. man what a bundle. suppose it isnt hurting anything as well. so i will continue to use it for a power slave.


mine is also a 92tbi car. just buy either a barry grant or the one in the tech articles. either will work. your tbi pump will only put out about 15psi.

 

what do u mean no spedo did it work before removing the ecm and now that you remove it it dont work? i am looking at the jet industries tcc kit.it says that you dont have to remove the pan.

 

yes the speedo works great with the ecm in there. i believe i seen on a diagram that it gets either a ground or power from the ecm.

 

That's weird on the speedo, on my 1992 TBI car the ECM was taken out 3 years ago, and the speedo has worked fine ever since.

And yes, that's the TC lockup sticky I was looking for - guess I couldn't see the forest for the trees!

 

yeah i didnt like it either. i was just reaching up and removed it. guess i need to get under there and see if i may have unplugged something else. of course then wiring power to the fuel pump relay and the choke. maybe another day. when i go to put in my new engine i am going to buy or build a totally new engine harness.

 

like i said im going to leave mine in.so that info helps i am looking at pressure regulators on ebay will a edelbrock 4.5-9lb work or will the 15lb pump blow by it

 

It has to be a return-style regulator if using the in-tank pump - if it's less than $60, chances are it's not a return-style.

 

it gives a return fitting size of 3/8 npt,dual outlet,single inlet,but yet says regulator styal non return

 

what would happen if i was to throw a t fitting inline for a return

 

The only pressure you'd get would be what was produced by the resistance of the slightly smaller return line.

Basically, zero pressure at the carb.

 

yeh i was talking to the foreman here at work that was what he said.butif i can get the return regulated than it would work.so im gonna put my dual out let adjustable regulator on put my fule in than to carb second out let to the return but install second regulator in return adjusted so it has less pressure than the first 1

 

good morning camaro lovers!! i had a great week end.my car is now carbed she hasent been started back up yet but the full change is almost complete.just have minor stuff to take care of. ie. pumps back on alt back on.waiting on pressure regulators to come (orderd them on friday) but all is going well.just so happens a buddy and i are performing this same swap on his 88 iroc tpi car.
has any one used the lock up kit for 79.00$ that was mentioned is this thread? i would like to know how it went and if any other parts were needed?

 

Saving info