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Fuel line question for TBI conversion

goathearder

goathearder

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Hey Guys,
I am converting the 73 over to TBI and I have a question on fuel lines. I went and bought a 91 gas tank and sender so I have a baffled tank and in-tank pump but the sender has the GM only o-ring flare fittings on them. I have been reading about people using AN-Sagniaw adapter fittings and other stuff and that all just seems a bit excessive to me so my question in this:

Can I just cut off the flare, remove the fitting and use fuel injection hose and fuel injection clamps or would that be no good? If I do cut off the fittings, do I need to put some sort of vacuum flare onto the line to get good sealing?

I'll go the adapter and fitting route if that is significantly better for some reason but I just want to check first.
 
goathearder said:
...Can I just cut off the flare, remove the fitting and use fuel injection hose and fuel injection clamps or would that be no good? If I do cut off the fittings, do I need to put some sort of vacuum flare onto the line to get good sealing?

I'll go the adapter and fitting route if that is significantly better for some reason but I just want to check first.
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I've helped 2 guys convert carb to TBI and have gone about the conversion two different ways.

Option 1:
He didn't want to do it the "factory way" so we did exactly what you described...cut the fittings and used hose and clamps from the tank to the TBI. No issues, no leaks.

Option 2:
We gutted everything off the TBI donor...tank, lines etc. and mouted/ran everything like factory.

Either way will work.
 
Sweet! This is exactly what I needed to know. I don't have a TBI donor (my kit came from affordable fuel injection) but I might run to the JY this weekend and see if they have something I can just pull all the lines from. If not, I'll cut the flares off and run clamps.

When he cut the flare off, did he put an extra little bump in the lines to help seal it or just he just run the line straight?
 
FYI power steering lines use same fittings .

dont forget tho EFI rated rubber hose for your flex sections . and hard lines for the long runs .

dont forget the inline filter and also 3/8 feed / 5/16 return / 1/4 vent .
 
Yep, got all that except the filter between the pump and the throttle body. I gotta figure out what/where I am going to put that.
 
goathearder said:
When he cut the flare off, did he put an extra little bump in the lines to help seal it or just he just run the line straight?
Click to expand...

He ran it straight with 2 smaller hose clamps at each connection and has had no issues.

Personally, I would try and leave the flare just to ensure positive sealing.

If you get some lines from the JY they shouldn't cost more than a few bucks. If you go with JY lines, be absolutely sure you clean and blow the lines out to keep crap from getting into the injectors.
 
I know ur a ways away J, but ur more than welcome to see what I've done in person some time. You can see most of it in y build and FAST system install, though I haven't finished the FAST thread :(
 
K85 Octane said:
I know ur a ways away J, but ur more than welcome to see what I've done in person some time. You can see most of it in y build and FAST system install, though I haven't finished the FAST thread :(
Click to expand...

Thanks Dude, I have been through both of those threads and it looks pretty straight-forward for the most part. The kit gets here on Friday and I have the tank and sending unit already so its just the lines. I think I might have found some lines on CL which would be perfect!

I broke my power steering pump in Big Bear this weekend so I gotta get that fixed (ordered a PSC to compliment my AGR box) so once I get that in and get the fuel injection in we gotta go hit some trails. We did Bullfrog out in Johnson Valley before we hit big bear and it was a pretty cool trail, I think you'd like it.
 
My theory is that GM only used the fittings on the K5's/Suburban's because the tank is under the passenger compartment.

On the pickup trucks, apparently all of those just used hose clamps. With the low pressure of TBI there should really be no problems.

Big fan of the threaded fittings, but the AN adapters are far too pricey IMO, so if you can't run them, hose clamping with proper fuel injection rated hose is fine.

It's unfortunate the saginaw fittings are so hard to make/uncommon, it makes cobbling a fuel system together more painful.

One other point, most GM cars in the late 80's and early 90's used the same fittings with braided steel fuel lines, and theoretically you could get enough of those to build the full line. :)
 
:haha:

i have had one for over 7-8 years now . i live in the rust belt . its a need to have tool. :thumb:

otherwise you be more than welcome to have me make you lines if you were close.

i just replumbed a 99 2500 NON hd last weekend . all lines new master to abs to wheels.
 
sweetk30 said:
not hard to make flare on hard line if you have one of these :whistle::whistle::whistle:


http://www.mastercool.com/pages/flaring_tools.html

if you do lines for fuel and brake you CANT go wrong on this kit. :bow:
Click to expand...

Oh, it's on the lists of tools to buy. I only plan to do two more sets of GM fuel lines, but I figure that thing will pretty much pay for itself. If you don't run the GM flare, you end up cobbling something together for the fuel filter, let alone the braided steel lines, etc.

If rusting brake/fuel lines were a major problem out here, I think I'd have bought it a long time ago.
 
So speaking of fuel filters, do they make a universal fuel injection one I can run between the pump and throttle body that doesn't use any crazy fittings?
 
I have been to o'reilly's a few times and seen their wall of fuel filters, I believe there are a fair number of Ford applications that just use a hose/clamp type setup.
 
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