Fuel lines

[Harleyboy1]

Was going to replace fuel lines from lmc trucks but noticed that it said that the fuel lines were for carburetor engines only has anyone used the original fuel lines on there trucks for the ls conversion if not could anyone give me the name and the part # of what they used i need to be able to maintain 60psi

 

[1987 GMC Jimmy]

Was going to replace fuel lines from lmc trucks but noticed that it said that the fuel lines were for carburetor engines only has anyone used the original fuel lines on there trucks for the ls conversion if not could anyone give me the name and the part # of what they used i need to be able to maintain 60psi

Not a good idea to use those low pressure lines with that LS fuel pump. If you can, try to find a 1987 fuel setup, especially the lines and tank, be used that setup is compatible with the LS pressure parameters. If you have duals, the stock style selector switch will also be overwhelmed by the pressure. Not sure what people are doing with that, but just a heads up there.

 

[Harleyboy1]

Thanks for the heads up will look into it

 

[chengny]

You should call Inline Tubes (586) 532-1339. Here are the 3/8" fuel supply and 1/4" return lines sets for 81-87 with FI. List for $115 each:

http://www.inlinetube.com/_p/prd14/...87-v8-1-2-ton,-1-4"-f.i.-return-lines-ctf8113

http://www.inlinetube.com/_p/prd14/...87-v8-1-2-ton,-1-4"-f.i.-return-lines-ctf8113

I say call because - although they do very good work - the product descriptions on their web site are sometimes both vague and confusing. Also it is - by far - the slowest web site I have ever visited in my life. Their sales/tech guys however, are outstanding.

BTW - if you have dual tanks, you will have to rewire your tank switching system to operate the in-tank pumps that are used with the FI version.

You must be registered for see images attach

As used with a TBI equipped vehicle, the tank select system actually has 3 functions instead of just the normal two. In addition to switching tank feed/returns and level indication, the dash switch also energizes/switches the associated in-tank fuel pumps.

Since the power supply to the fuel pump must continue - even after the plumbing and level indication have been changed over - the momentary switch/motorized actuator set up used from 81-86 was not an option (apparently the same wiring harness was to be used in model year 1987).

A solenoid operated actuator operated by a rocker switch (the pre-81 design) was also not a viable option because solenoids only use an O/I type signal - they move in one direction when power is applied and only move back due to spring pressure when power is secured. The fuel pumps each needed their own power supply - that was switched on and stayed on - when it's tank was selected.

So, both pumps needed power even after the tanks were switched over. But a solenoid set-up was only on/off not left/right and a standard motorized actuator would burn up if power was left on for any considerable length of time.

In the end, it appears that Pollak developed an actuator that was specifically for the 1987 model year. It is a motorized actuator with a rocker switch that killed the power only to the motor windings (and continued to supply the pumps) after the valve had shuttled. That allowed GM to use the same wire that moved the valve to supply power to the fuel pumps.


Here read this - it explains it much better than I am:

The information I have is the 87-91 carbureted & TBI trucks used a 4
terminal dual pole dual throw rocker switch (D7089C - #15599081) and a motor
type switch-over valve (not solenoid operated) that included a fuel level sender
switching circuit and switch-over current control (#15548879). This system
was very similar to the previous carbureted trucks with the exceptions of
the rocker switch no longer is a momentary type switch and once the
switch-over valve is in commanded position, the unnecessary current flow is
ended by an switch and diode circuit within the switch-over valve itself.
The left & right fuel level circuit switching is handled internally by the
switch-over valve.

 

[Swims350]

the line kits should work, the problem is the pre 87 ones use rubber hoses to connect them to the fuel pump and the sending unti that's a no-no for fuel injection. Now my thought would be some AN adapters maybe or some compression type fittings on the steel/stainless hard lines, those can be bought to handle high psi. For that matter you can buy your own hard lines in coils and flare them or whatever you want.

By saying they should work I mean I would think the steel lines or stainless ones themselves would hold the 60 psi. I don't know for 100% as I have never done it but brakes use steel lines, not sure what kind of psi the brake system has either.

You would have to do like I had mentioned a find a 60 psi or stronger compable way to connect them to your fuel pump/ sending unit, and then to your fuel pressure regulator, fuel rails whatever it is they use.

 

[chengny]

the line kits should work, the problem is the pre 87 ones use rubber hoses to connect them to the fuel pump and the sending unti that's a no-no for fuel injection. Now my thought would be some AN adapters maybe or some compression type fittings on the steel/stainless hard lines, those can be bought to handle high psi. For that matter you can buy your own hard lines in coils and flare them or whatever you want.

By saying they should work I mean I would think the steel lines or stainless ones themselves would hold the 60 psi. I don't know for 100% as I have never done it but brakes use steel lines, not sure what kind of psi the brake system has either.

You would have to do like I had mentioned a find a 60 psi or stronger compable way to connect them to your fuel pump/ sending unit, and then to your fuel pressure regulator, fuel rails whatever it is they use.

Do you mean the kits noted above - from Inline Tubes? I have only purchased their brake lines, so I can't honestly comment on the quality of their fuel lines. But I think they have that figured out too.

If your concern is that they sell the same kit for both carbureted and fuel injected delivery systems, without being aware of the different requirements for each...you probably shouldn't be too worried.

There are a few clues in the product descriptions that would allow one rest assured - they have things well under control:

1. The kits for the two types of supply lines have different product codes

2. The text for the fuel injected kit includes FI and Fuel Injected, while the
kit for a carbureted system makes no mention of the type of system it is
intended for.

3. The FI kit contains 3 pcs and the carbureted kit consists of just one piece.
To me, that would suggest that the rubber transition hoses typically used
with a carb system (at the sender head and in the engine compartment),
are replaced with steel tubing when a FI kit is ordered.

4. The price for the FI kit is nearly double that of a standard kit. This is most
likely due to the increased cost of the materials used to produce a kit that
meets NHTSA requirements for FI systems.

You must be registered for see images attach

You must be registered for see images attach

I think Adan would be alright if he bought from Inline.

 

[Swims350]

no I meant any kits lmc classic etc. they should be steel or stainless steel hard lines and work with the right fittings to couple them instead of the rubber lines with clamps.

 

[Harleyboy1]

Called brothers trucks this morning to ask about the quality of their fuel lines seems they are in the catalog but they couldn't find them on their website any more thinking of making my own fuel lines to connect both fuel tanks now have to figure how to hook up to the selector valve p# fsv3 rated at 65psi here will have to flare the steel line and use a high pressure fuel injection hose to connect to it. Don't really see any other options . Unless I sell the new 16 gallon tanks that I bought for the 87 R10 and just buy the 20 gallon tank for drivers side and be done with it . Weld passenger door shut seems a lot easier at this point.