Hello everyone,

I've been searching the site for awhile now trying to figure out what needs to be done in regards to the fuel pump for a ls1 swap into a 305 carbd car? I know the TPI is an in tank pump but the one on my 86 is not i believe, besides replacing the entire tank with a 4th gen one what are my options? Are there in line pumps that will work with the LS1 fuel system? I guess I am confused haha

 

The 3rd gen lines for a 305 carbed car run on the passenegers side of the car. You will need to go to a junk yard and get the fuel lines all the way from the engine to the the fuel tank from an EFI car. I believe you may need the EFI tank with the fuel pump in it. But I would recommend going with the 4th gen tank and pump. Then you can buy a fuel conversion kit from hawks or f-bodymotorsportst;great service on fbodymotorsports, to connect your existing fuel lines to the engine for a professional look. You can go the way I did it since I didnt have enough money for the kit. When you get the EFI lines try to get the rubber hoses that are screwed into them that run into the engine and just hook it up to the LS1 engine. Hope this helps, any questions let me know.

 

thanks,

so if i go get an efi tank will the gas guage sender from my carbd car work with the efi tank or will i need a new sender as well as purchasing an in tank pump? i was gonna do the 4th gen tank since i have it sitting around (it's a 98 so its not plastic) but i've heard that the guage sender will not work with my guages even if i decide to go aftermarket such as autometer. can anyone shed some light on this? I want to have a working fuel guage

Thanks,
Jeremy

 

You will need an entire TPI setup from the tank plus all of the hardlines going to the front. You can use a fuel tank and lines from a V6 MPFI car, but will need to upgrade the pump. When I say entire setup, I mean sending unit and all.

 

thanks,

so since i need the sending unit will it read the same as the stock one on the guage or is the unit somewhat different that it will make my fuel guage be off a bit? once again thanks for the help so far! also are there any good sites to find all the hardlines, i suppose shipping that would be a PITA, i went to some junk yards but i didn't fine anything in good shape

 

Nobody seems to know much about this. The LS1 sender reads 33 ohms at empty, and 270 ohms on a full tank (according to LS1Tech). Our gauges go from 0-90 ohms. I haven't figured out how I'm going to convert it, but I might have to take the sending unit apart and install a different resistor. Most people have just used the stock fuel tank/sender, or have installed a 4th gen dash/gauges, so they didn't run into this problem.

Not that I know of. You could make your own hard lines, or buy some braided fuel line and use that.

 

The sending units in any of the TPI or MPFI cars are the same, so you don't have to worry about the fuel gauge being off.