Madcrazy

I broke the return line on my tbi 305. I can't seem to find this line anywhere. I was told by someone I could just block off the retrun and he said thats what he did but he has an LS1 so I am unsure as to whether it is applicable to the obdII motors. Would this be ok to do and if so can anyone explain to me what I would need to do. I have a good idea but am unsure since I have never done this before. Also, if anyone has that return fuel line that runs from the tbi unit to the fuel line along the fender I would like to buy one.

Home Built

My understanding of blocking the return line would not be a good idea.
If you do then the fuel pressure would be to high and you would run extremely rich.
since the retun line is not under any pressure you could just splice a piece of fuel line in between the break.

Just my .02

swerve-driver

I would be careful of what that someone told you. The return line is there for a reason. I would have to imagine if you deadhead the fuel pump by blocking the return line, it will toast the pump and all the extra pressure built up before pump failure might cause leaks on your injectors, AFPR, etc... leaking.
ATI Procharger actually uses a device that essentially restricts return flow back to the fuel tank to increase pressure at the injectors, which increases the amount of fuel being delivered.

If you can't find hardlines, there are alternatives out there. I posted this thread a while back-
https://www.thirdgen.org/forums/tbi/...ght=fuel+earls
You could just get the return line setup.
Hawks Thirdgen came up empty? I actually just wrote them about some wheels and haven't heard back from them.........
Best-
S-D

novadk13

Not sure why but the 88 I had the guy swapped in an LS1 tank with the ls1 pump and it was running to the FPR with no return from the TBI.

RBob

iTrader: (1)

I'm fairly certain the LS1's are a returnless system, no return line. The y-body's have the regulator in the fuel filter, with the f-body's having them in the tank in the 'fuel container.' There may be some varience to where the regulators are located.

And please, don't take this as an absolute, as I do not know how each MY was set up.

Madcrazy, could also check with junkyards to see if they have a line.

RBob.

FreeLoader

everything I've read about the ls1 tanks also says they're returnless...I'm not sure where that guy was coming from.

as for whether or not to block it off, if you have the ability to adjust your regulator, you could just back off the psi a bit and block off the return line, I can't really see a downside to it.

also, that would actually improve the maximum pressure of the stock pump, which would allow you to use it a bit longer.

that is, if it doesn't die from the fact that you're making a 16+ year old pump work harder, heh.

as for whether or not it'll kill it from simply becoming returnless, I doubt that'll happen, there's not a whole lot of difference between the ls1 pumps and the tpi pumps, or even the tbi pumps for that matter, most of the differences are related to maximum fuel pressure, not so much quality.

that's all just my opinion though, no facts. in fact, i'm not sure anyone has tried it yet.

swerve-driver

Item number: 270027138267
This is on e Bay. Won't get much easier.

Madcrazy

thanks alot. I appreciate it.