I don't know to much about the tpi system what all will I need to do and or get I'll have the intake, injectors, wiring harness, computer, fuel pump and knock sensor is there anything else and is it worth it I'm trading the guy my brand new 750 elderbrock and high rise air gap intake for this any info is helpful

 

from looking at your info about your car it seems healthy. Stock tpi will lower your current horsepower and raise torque. Im going tpi on my 327 sbc in my 92 trans am and its taking a lot of money and parts to make it work right. Then modifing the tpi for high rpm and big horsepower takes money and lots of it.

im just saying start searching and doing homework before taking the plunge and gong efi

 

thanks for the info I was wondering how that would effect my horsepower and torque as well

 

I just found out that the set up if off a 91 vette does that make a difference

 

Is the set up complete including the computer? I think your biggest obsitcal will be the wiring harness. I understand from a friend (Dyno Don here on tgo) who has done a lot of tbi to tpi and carb to tpi conversions that the bulkhead connection plug changed between 1989 & 1990 on the F-body cars. I don't know what sort of connection the Vette used. I also don't know if the bulkhead connection for the harness changed between 1982 & 1985 when they first came out with tpi. You will probably need to get a harness from a 1985-1989 tpi or a cutom aftermarket harness to wire it up. You might be able to convert your original 1982 harness, but you will need more wires because there are a lot of sensors on the tpi engines that are not on the 1982. You will need to repin the harness and you should buy the necessary Helms manuals to get all of the wiring diagrams you need to modify the harness with. You might be able to add the necessary wires to your 1982 harness to make the tpi work. You will want a big table to spread the harness out on. Diagrams for the harness you are starting with and the harness you want to end up with, and a volt ohm meter to check continuity with to make sure the wire you grab one end of is the same wire when you find the other end. You will also want a roll of masking tape to mark and label the wires as you change your harness. You will need to re-pin the plugs in the ecm because the various ecm's that GM uses use the same pins, but each application has the inputs and outputs in different pins. You might be able to use the Vette harness with a modification to the hole in the firewall to fit the bulkhead connection. The problem is that because the Vette is a smaller car, many of the wires may not be long enough and many of the components may be in totally different locations in the Vette necessitating shortening some wires and lengthening other wires. When you modify your harness, resist the temptation to use crimp connectors to make splices. Solder and heat shrink all connections. It is more work up front, but when you start having wires break at crimps, corrode because of dissimilar metals between copper wire and steel crimp connectors, or crimps getting loose, you will wish you had nice soldered connections insulated with heat shrink. Also be aware that up until 1989 the tpi systems were maf systems with a very limited, slow ecm. The system out of the 1991 Vette will have speed density and a much faster computer. If you end up converting an older F-body harness, you will need to convert it to speed density.

My 1987 Trans Am originally had a carbureted 305 with a t-5. We swapped out the 305 for a 350, and converted the 350 from tbi to speed density tpi. The lady I bought the Trans Am from wanted to see the car when I finished it, so I took it by after it had had the mechanical work done and body and paint work completed. We were talking and I mentioned to her that I was getting 20-22 miles per gallon on the highway with a lot more power. She told me that the best mileage she had ever gotten out of the carb'd 305 was 13.5. If you want a high horse power tpi, it will take a lot of work and be fairly expensive. If you just want a nice driver with a stock tpi, it is well worth the effort to make the conversion as far as I'm concerned. I would never want to go back to a carburetor.

 

the wiring and computer are a plug and play thing.....buy f-body harness and sell the vette one...enough said


biggest hurdle is fuel system. need the tpi fuel pump and fuel lines

 

You're preaching to the choir, Sir. Not many of us would revert for a daily driver, or even a moderate track car.

The fuel lines are different on a Corvette TPI, so keep that in mind.

 

yepper. ive got a chevy high performance mag that has a fuel pump extravaganza in it, its the Feb 09 issue. it has two fuel pumps that are really affordable and are pretty much direct replacements for stock pumps, just better performance.

1. Holley electric in-line pump; (PN- 12-920) Free flow rate: 67 psi. Max pressure: 100 psi. 10 mm inlet/outlet sizes with 3/8 barbed fittings included. supports: 800 hp TBI apps. 700 hp MPFI n/a apps. 600 hp MPFI forced-induction apps. pump rated for continuous duty and tested for 2500 hours. price: $168

2. Mallory model 255 high performance electric pump; (PN- 4259) Free flow rate: 264 lb/hr. Max pressure: 100 psi. inlet size: n/a, outlet size: 5/16 hose. Applications: High performance direct replacement for stock in-tank pumps in 85-92 GM vehicles. comes with complete hardware package for easy mounting. price: $177

both are well priced for the performance they deliver, and would certainly be better than the stock pumps. the mallory in my mind would be the best one, with better free flow rate and its direct replacement in the tank. then again, if your car didnt have an electric pump to start with, im sure the holley would be easier, just stick it right in front of the fuel tank.

the corvette lines should feed from the passenger side rear of the fuel rails, and i believe you can get braided steel fuel hoses from auto parts stores and/or summit/jegs.

good luck with your swap, this is a good place to find info, the peeps on here know thier stuff. Good Luck!

 

if you have a bunch of money and time go with the tpi

just keep in mind that if you replace all the sensors, a chip, injectors and the list goes on you will be married to your thirdgen

 

I'm also about to sawp from carb to TPI, except i have a 94 TPI. Can i use a 3rd harness or do i have to get a 4th gen? If i do have to go 4th gen, will the connector match up with the connector in the car?
Good Luck Mario

 

i think the LT-1 style heads are different than tpi and older, but not sure on that. also, you will most likely need the 4th gen harnes and computer, cuz i dont think the tpi and lt-1 series are the same. best off to get as much of the 4 gen parts you can get your hand on, and keep the swap as simple as possible.