How do I convert a 2.8L carb to TBI using parts from a GM 4.3L TBI?
 

I was reading this guide to try and get more horse power from my 84 s10 2.8L V6 http://www.4x4wire.com/tech/60degreeV6/ and the first step is to replace the carburetor with a TBI from a GM 4.3L V6. This sounds like a good way to get an extra boost, but I am not sure of exactly what all I will need to pull from the donor vehicle. I understand that if I were to replace the motor with a 4.3 that this would be a better option, but that is not in my budget right now. I flipped the lid on my air filter cover and added a K & N air filter, and this drastically improved air flow, but I really want to add the TBI. Has anyone successfully done this? From what I have read it is a direct fit and the mod only takes like 2-3 hours. http://i955.photobucket.com/albums/a...r/101_0344.jpg

sounds like it will be a bit more complicated then that. i swapped out my 85 2.8 tbi for a 83 2.8 carburetor set up and i had to swap intakes too which involves pulling all the rocker arms and push rods too. i dont think that anything on the 4.3 is gonna work on a 2.8.

i just read that article. and it doesnt specify what the 2.8 WAS. it refers to that the 2.8 ECU will handle the 4.3 throttle body. so it might be a direct bolt up to a 2.8 tbi not a carb'ed 2.8

How about a direct replacement bolt in engine from GM Goodwrench: http://www.crateenginedepot.com/HT-3...230-P25C2.aspx

I expected that would be too easy
 

well...I want to do all the mods on the list, and I wanted to get a manifold anyway so I don't have to take apart what I have until it is ready so that is not a big deal to have to swap the intake manifold since I want to port match it anyway. I really just am not sure what all the parts I have to pull is all as I have never worked with a TBI before. Maybe I just need to go to the junk yard and take a look at what all is involved.

youll need the wiring harness. your also gonna have to get a different fuel pump as the tbi has a higher psi then a carb. might have to get a new distributor. i dont know if your gonna need the vss sensor. i was told you do. it was about 9 years since i did the tbi to carb swap so dont really remember everything that i had problems with

The HT 3.4 V6 Crate engine is a good option, but I would have to find someone with a shop or pay someone to install it. I am in student housing right now and garage less. I was kind of looking to hold me over to work on now until I have the right conditions to drop a new engine in it...well now I have some options to weigh. Thanks for all your input guys.

If your 84 is like my 84 then you have a mechanical fuel pump driven off of the engine. The TBI uses an electric pump mounted in the tank so I think you're looking at doing that as well. Plus all of the paraphenalia that goes with it. I don't thing the manifolds are remotely the same for mounting a TBI unit on the carbureted intake but there are aftermarket ones you can get. Thought about doing this myself a few times and still may.

They do sell inline fuel pumps you can buy to put in your frame rail so you don't have to deal with dropping the tank. Makes it so much easier

The TBI is controlled by the computer so you have to be able to have all the correct inputs. Throttle Position Sensor, Idle Air Control Valve, The injectors themselves need to be controlled for pulse and duration. The O2 Sensor and EGR along with the temperature switch controls open/closed loop operation. If you can get either a manifold or an adapter plate for the TBI then you need to get a complete wiring harness and computer from a donor vehical. Also the computer itself has a prom for each vehical for performance. A stock chip may work I do not know. If you do all your research and get all the right parts and all of the inputs to work correctly this could be done. It also depends on how much time you have to work on this and if you have a problem how long can you do without your car running. I do love my TBI unit on my 4.3 it is reliable and trouble free.

You are much better off getting all the TBI stuff from a 2.8 and doing that swap first. The 4.3 TB mod is not a bolt on and the TB from a s-series aint really the best to use. You have to bore out the intake to fit the bigger bore of the new TB. The s-series 4.3 TB doesn't have the holes on the side to bolt the throttle bracket to. I drilled and tapped the holes in mine but cause I'm cheap and got my TB for free. I've seen some full size and astro vans with the correct TBs (4.3, 5.0, and 5.7 all have the same bore TB). Also on the 2.8 you still want to run the 2.8 injectors or it will flood out.


The stock 2.8 chip will run everything just fine. I'm running a stock chip on my hopped up 3.4 with 4.3 TB and injectors with no problems. I do however plan on burning a chip once I get it broke in and get all the supplies ordered. I did get on it a few weeks back and walked off on my buddy in his ZR2, lol.