Carb to tbi swap

[Blizzaro]

New to the site and hoping to get some insight on doing a motor swap from my 88 k5 into my 84 k20. I want to keep the tbi motor all together and put it all in the 84. I know the computer and fuel pump need to go in with it. Anyone have more info on what needs to go with it to make it work?

 

[Country705]

I am not completely sure what all has to go with it but I imagine all the sensors and wiring along with the computer and the tbi components. I think this has been discussed before so someone with more experience can chime in. This group of guys here have a vast amount of knowledge and can help you. Again

 

[Jims86]

Welcome.
You will find all you need in the engine and performance sub forum of TBI and EFI swaps.

 

[MrMarty51]

I have a question that I do`nt think has been answered.
If a person using the 79 tanks, installed a return pipe through the sending unit cover and an inline fuel pump, would there still be cavitation from braking/cornering if a 1/4 of a tank of fuel was maintained???
Or would it take closer to a half ???

 

[Irishman999]

I have a question that I do`nt think has been answered.
If a person using the 79 tanks, installed a return pipe through the sending unit cover and an inline fuel pump, would there still be cavitation from braking/cornering if a 1/4 of a tank of fuel was maintained???
Or would it take closer to a half ???

Good point buddy, You have to change the fuel lines and sending units from the tank. Regular fuel line wont work, it will explode. Im drunk, cant remember. There is some **** with the fuel system though.

 

[Jims86]

You need to use SAE J30R9 fuel line for the rubber parts. Usually dont get problems until around 1/8...especially in a burb or blazer will let you know that you are close to out of fuel on hard cornering and accelleration. Tanks before 87 did not have the baffles that keep fuel gathered around the fuel pump pickup sock.
That said, I have been using my stock 86 tank for 11 years, just dont let it get too low.

 

[MrMarty51]

You need to use SAE J30R9 fuel line for the rubber parts. Usually dont get problems until around 1/8...especially in a burb or blazer will let you know that you are close to out of fuel on hard cornering and accelleration. Tanks before 87 did not have the baffles that keep fuel gathered around the fuel pump pickup sock.
That said, I have been using my stock 86 tank for 11 years, just dont let it get too low.

This helps a lot, I know the proper way would be to get the tanks,senders and pumps along with the factory fuel lines, but, moneys real tight and I do have a inline pump with an adjusteble regulator so it seems about the only other requirements would be a switching valve from a 87 or newer and some return lines, which I think I can drill and solder into the original sender units mounting flanges.

 

[Jims86]

This helps a lot, I know the proper way would be to get the tanks,senders and pumps along with the factory fuel lines, but, moneys real tight and I do have a inline pump with an adjusteble regulator so it seems about the only other requirements would be a switching valve from a 87 or newer and some return lines, which I think I can drill and solder into the original sender units mounting flanges.

If you can round up another inline pump, you can build a small fuel reservoir can that will serve the same purpose. 1 pump as a lifter to fill it, than the other after to provide pressure to the TBI. run a return line from the res, t'ed into tqhe TBI return line.
This give the 2nd pump a constant supply tqo draw from, even if the fuel runs away from the in tank pickup when low.

 

[MrMarty51]

If you can round up another inline pump, you can build a small fuel reservoir can that will serve the same purpose. 1 pump as a lifter to fill it, than the other after to provide pressure to the TBI. run a return line from the res, t'ed into tqhe TBI return line.
This give the 2nd pump a constant supply tqo draw from, even if the fuel runs away from the in tank pickup when low.

So, the first pump, could be a low pressure to feed the reservoir then the return,from the high pressure pump/regulator would be Td into a return out of the reservoir and then back to tank, so, any thing returning would all be hooked together and back to tank to ensure there would be a free flow of returning fuel ???
When I was expirmenting with My 78 MG-B, I found that running a loop back into the high pressure pump without a return to tank caused the high pressure fuel pump to over heat and begin to fail, OUCH !!!, so I built into it a return to tank and problem solved, no more over heating fuel pump, I had a problem with bad injectors so I disasembled that system and installed an older intake manifold with twin SU carbs to get it back on the road again.

 

[Jims86]

So, the first pump, could be a low pressure to feed the reservoir then the return,from the high pressure pump/regulator would be Td into a return out of the reservoir and then back to tank, so, any thing returning would all be hooked together and back to tank to ensure there would be a free flow of returning fuel ???
When I was expirmenting with My 78 MG-B, I found that running a loop back into the high pressure pump without a return to tank caused the high pressure fuel pump to over heat and begin to fail, OUCH !!!, so I built into it a return to tank and problem solved, no more over heating fuel pump, I had a problem with bad injectors so I disasembled that system and installed an older intake manifold with twin SU carbs to get it back on the road again.

I like to use the same pump for the Lift(#1) and the TB I pressure(#2), that way, you garentee the same volume betwix the 2. the return line from the res tank is there to keep the tank from pressurizing to the point of doing damage.
The fuel outlet from the res should be at the bottom. I like the bottom of the res to be domed a little, or even coned a little, and then the fitting centered. Returnline can exit the top,and the feed from the tank in from the side.

 

[MrMarty51]

I like to use the same pump for the Lift(#1) and the TB I pressure(#2), that way, you garentee the same volume betwix the 2. the return line from the res tank is there to keep the tank from pressurizing to the point of doing damage.
The fuel outlet from the res should be at the bottom. I like the bottom of the res to be domed a little, or even coned a little, and then the fitting centered. Returnline can exit the top,and the feed from the tank in from the side.

OK, it is an old thread, but.
I am replacing the fuel tank switching valve and I will search for that information, to change it over to the 87 valve, for TBI, but.
I have changed the dryer on the A/C of My 93 GMC and the bottom of that canister is domed outwards.
If that canister is flushed real good to remove any oil, I wonder if it could/can be used for a reservoir for the fuel system ????
Just curious is all.

 

[Jims86]

OK, it is an old thread, but.
I am replacing the fuel tank switching valve and I will search for that information, to change it over to the 87 valve, for TBI, but.
I have changed the dryer on the A/C of My 93 GMC and the bottom of that canister is domed outwards.
If that canister is flushed real good to remove any oil, I wonder if it could/can be used for a reservoir for the fuel system ????
Just curious is all.

Nahh, not unless you cut it open, and gut it. You can also use a res from an 87-89 f series truck, and 84-89 bronco.

 

[MrMarty51]

OK, I`ll be a scrapping for one then.

 

[89Suburban]

Posted From Hell

 

[chevyman]

fuel pump

new to this site so not sure how to post. I did an engine swap on my 85 sierra classic. went form 302 carb to 350 TBI. I need to install an electric fuel pump but need to figure out how to do the wiring. meaning from the battery all the way down to the pump it self. last peace to the puzzle and cant figure it out. iv done a lot of research and cant find anything. maybe not looking in the right places.