[ForceFed86]

Helping a friend put a SBC in his 88 s-10. Motor/trans are installed. Working on the fuel system. The engine has an aftermarket mech pump. The old s-10 was fuel injected and still has the in-tank fuel pump and return line.

What is the best way to convert the system over to a CARB setup. Can we leave the EFI pump installed? Should we use the return line or convert to dead head?

Thanks

 

[eric32]

Well I hope this helps you out. I have a 86 and 96 s10 that I have converted to carb and you will need to take out the electric fuel pump in the tank to begin with. Your mechanical pump will have a hard time to pull fuel through it. I only use the main fuel line and have the return line and the others plugged off. Also on your sending unit you will have to modify it so it will pick up fuel to the bottom of your tank. I don't know what my dad did to make mine do that but that is somthing you will have to do. Look up some forums on s10 v8 conversions and ask around and you will be able to get more answers. I am doing a fuel tank drop this sunday on my 96 s10 and have a new fuel sending unit I am installing and I will have to modify it so I will post on what I had to do.
Eric

 

[bobscogin]

What is the best way to convert the system over to a CARB setup. Can we leave the EFI pump installed? Should we use the return line or convert to dead head?

Thanks

I used the stock "in tank" EFI pump. It operates at a pressure that's too high for a carb, so I put a T fitting in the line to the carb and used a regulator to bypass some fuel back to the tank through the return line. This dropped the pressure to an acceptable level. Worked for me.

Bob

 

[Soule88]

if you use the stock pump, DONT dead head it. it will cause the stock pump to overheat and die early, but you dont have to take it out. a mechanical pump will pull fuel through it. its not the ideal set up tho. there should be three lines coming up the frame the biggest is feed middle is return and the smallest is a vent

 

[eric32]

Well to help you out some more. I took out my old fuel tank the other week and got a new one. I am using my old sending unit and all I had to do was take out the fuel pump from the sending unit. Now for fuel line I am just using my main fuel line and have the vent open and the other's pluged. So am running one line and nothing more.I got rid of the return line since I am running carb. Whether using a mechanical pump or electric it helps to remove the old pump. I could not get my truck to run with the old pump in my older 86 s10 so we took the pump out and put sending unit back and an all is done. Worked like a charm.
Eric

 

[Siggy_Freud]

You can also consider using both an intank pump, and an inline main pump. The intank feeder pump will help take some heat out of the inline pump. You can use a fuel pressure regulator if you're worried about exceeding recommended Carb fuel pressure specs.