I have a 89' 305 TBI that i have swapped into my 92' RS and i have been having trouble with the wiring and such, so i decided to go with carbed. I was just wondering what all i have to do to switch successfully so the car doesnt run like crap. Im going to try and modify my V6 mpfi wire harness to work. What would i do about computer and torque lockup. Im swapping intake, carb, and hei from a 84' cam. Please post any suggestions that will make this somewhat easy.

 

If you are swapping the factory stock intake, carb, and HEI from a '84 Camaro, you will need the entire portion of the wiring harness that starts from the passenger side fender well, and all the sensors it connects to, and the computer from that car. You may run into other harness peculiarities due to the difference in years. But, that will also take care of the torque converter lock-up issue.

Any particular reason you didn't get the entire engine from the '84 as well?

What are you doing for exhaust?

 

The carb set-up from an 84 camaro isn't that great. I have one, it doesn't use an HEI distibutor, like the older 305 engines. It uses a computer controlled set-up. If I were you I would do what I did, throw the electronics in the garbage and buy your self a 600 cfm carb, and an older HEI dis., but if you go to an edelbrock carb you will have to get a spacer that holds the carb, it won't match up with a stock intake manifold.

Sage

 

The factory '84 carb has fantastic potential for street performance. The rest of the '84 engine, I'll have to admit, isn't that great. But, the '84 engine heads will be better than the '89 TBI engine's heads.

You really need to think through what you're going to do. It should be just as easy - well, probably a lot easier - to do the complete '89 TBI set-up as it would be to do the '84 carb set-up.

 

Well the engine in the 84' does have HEI but it looks like the guy made some mods. to it because the whole wiring harness going to the computer is cut. I figured i can just make some mods. to the v6 harness so it will still work the starter and such things needed. Ive just been having so many problems with the TBI swap that i think it will be easier to just go carbed. Such as when i turn the key to start it sometimes wont do anything and sometimes it will give power to the starter which is why if i go with the v6 harness i know it worked before and it should still at least give power to the starter. and the exhaust situation is already takin care of.

 

If the '84 was properly "de-computerized", then it shouldn't be too much trouble to put it in your car. The way you first stated it sounded like it was still factory stock.

The torque converter lock-up can be accomplished with a manual switch, a kit from an outfit like TCI or B&M, or you can get into the tranny and use the 4th gear indicator pressure switch to ground the lock-up solenoid. If you do the 4th gear thing, it's a good idea to put a vacuum switch in series with the power wire.

 

Here,
five7kid is a smart guy.. and sounds like he knows what he is talking about. if you dont understand him here is a article that might be usful on taking out the computer just ignore the EFI part about it


https://www.thirdgen.org/newdesign/tech/carbswap.shtml



This is what i am going to use in the summer.. i have a 84 camaro also and getting rid of the disbutor and the carb. i have already deleted most of the stuff. Good Luck

 

One significant issue is the '92 car will have an electric in-tank fuel pump, where the '84 only had a mechanical pump on the engine. You can put a mechanical pump on the '89 engine, but you need to do something about that in-tank pump - either remove it; or wire it up to "push" fuel to the mechanical pump, which will require the use of a pressure regulator. Looking over the topics posted in the past few days on the Carb forum will yield information about that issue.

 

Would it be all that hard to just get a new Fuel cell? Just Drop the old and fit a cell in? i think that would cut alot of time, but will add to the expenise.

 

The hard part is getting the tank out and back in. Switching/modifying the pick-up is the easy part.

But, if you find a carb tank in the JY or have one from a donor car, you can make sure it's ready to go before you tear the car apart - I suppose that's an advantage.

 

I already have the tank out and am going to put an in-line pump on. But my concern now is that the car wont do anything when the key is in the start position when i have the tank (wires going to fuel pump that come out of tank) disconnected. Well when i put the inline in wont the car recognize there is no electric fuel pump connected in the tank and not allow the car to start?