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Question about fuel lines and high pressure pump

bassackwards

bassackwards

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I replaced the braided fuel lines with the rubber lines that Edelbrock specified and when I dropped the tank I found more braided lines there. They said nothing about replacing these but I have a piece of their rubber line left.

What did everyone else do when you went high pressure?

I have the tank out now and am ready to stick it back in today

1989 TBI truck
 
Are you keeping the TBI system or upgrading.
Kind of confusing "edelbrock" specified for???
I use fuel injection rubber lines or all metal when possible.
A little more info in regards to what you are trying to accomplish please
 
MEMO43 said:
Are you keeping the TBI system or upgrading.
Kind of confusing "edelbrock" specified for???
I use fuel injection rubber lines or all metal when possible.
A little more info in regards to what you are trying to accomplish please
Click to expand...


Upgrading to Edelbrock MPFI and a 65 psi fuel pump. They sent fittings and rubber hose and instructions to replace both the supply and return from the throttle body to the hard lines inside the frame rail and a short piece that went between the pump to the hard line inside the tank.

They did not send any fittings or include any instructions for replacing the braided lines connecting the sending unit to the hard line inside the frame rail. I have enough of that expensive hose they sent to replace the pressure line but not the return. I would also have to find the correct fittings since I used everything in the kit.

I hope that the factory return line can handle the job that close to the tank since it will be open on the end
 
Make sure the line sizes are ok. The rubber is only intended to be a short piece to transition

there is a large percentage of us that went with braided line
 
Bent77 said:
Make sure the line sizes are ok. The rubber is only intended to be a short piece to transition

there is a large percentage of us that went with braided line
Click to expand...


This rubber hose is 3/8 and $5/foot and can handle 250 psi gasoline at 300 degrees. It is tough stuff

Edelbrock says it is up for the job, my concern is the original braided hose right out of the tank.
 
bassackwards said:
This rubber hose is 3/8 and $5/foot and can handle 250 psi gasoline at 300 degrees. It is tough stuff

Edelbrock says it is up for the job, my concern is the original braided hose right out of the tank.
Click to expand...
The factory TBI line?
 
I am guessing the piece of fuel line you are talking about is quite old. Better to replace it now than after everything is back together, and it decides to explode. There are some people on this web site that know what AN adapter fittings are needed to connect high pressure fuel line to a GM stock type fuel tank sender.
 
1-ton said:
I am guessing the piece of fuel line you are talking about is quite old. Better to replace it now than after everything is back together, and it decides to explode. There are some people on this web site that know what AN adapter fittings are needed to connect high pressure fuel line to a GM stock type fuel tank sender.
Click to expand...


I'm sure is is 1989 vintage, everything else was
 
bassackwards said:
I'm sure is is 1989 vintage, everything else was
Click to expand...

The return lines you do not have to worry about. The fuel PSI on those is not all that high so any type of fuel injection hose from a parts store would be more than enough to handle the job.
 
The fuel line supplied in that kit is Aeroquip pushloc.
 
1-ton said:
The return lines you do not have to worry about. The fuel PSI on those is not all that high so any type of fuel injection hose from a parts store would be more than enough to handle the job
Click to expand...
60 psi pump on that kit.
 
bassackwards said:
I know but it seems like the line from the sender to the filter has the highest pressure of all. I think I'm going to at least change the pressure side if I can get the fittings tomorrow before the parts house closes at noon
Click to expand...
Everything behind the regulator is the same pressure
 
Last edited:
bassackwards said:
Not really, It is greatest closer to the pump.

https://www.engineersedge.com/fluid_flow/pressure_drop/pressure_drop.htm

Pressure drop is exacerbated by bends, elbows, fittings, and different materials along the way.

If the fuel wasn't moving it would stabilize but velocity is a significant factor in pressure drop
Click to expand...
But the difference is really not enough to worry about, a few psi across the length is not enough to warrant re-engineering where the rubber section goes
 
Bent77 said:
But the difference is really not enough to worry about, a few psi across the length is not enough to warrant re-engineering where the rubber section goes
Click to expand...


If I have 70 psi at the end of the sender in order to have 60 at the regulator on a 30 year old fuel line that was intended for 17 psi..... But who knows, this might be the same line they used on the TPI cars.

I think I need to change it if even for my own peace of mind. The truck is lifted and the tank is out so access is as good as it will ever be... I hope. I don't ever want to be working on this section again
 
bassackwards said:
If I have 70 psi at the end of the sender in order to have 60 at the regulator on a 30 year old fuel line that was intended for 17 psi.....

I think I need to change it if even for my own peace of mind. The truck is lifted and the tank is out so access is as good as it will ever be... I hope. I don't ever want to be working on this section again
Click to expand...
That is the most important part. Did you measure the pressure at the rail when you did that?

I’ve tested tbi units before with 15 at the pump and 14 at the reg. I used rubber line on that without issue

@6872xtc is using factory TBI lines on his Edelbrock system
 
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