Fuel lines

[jdavidsmi]

Working on the 86; EFI, duel tanks, plastic fuel lines , in tank and frame mounted pumps, inline reservoir

If you needed to replace the plastic fuel lines, what would you replace it with? Plastic, rubber or metal?

And where can you purchase the quick disconnects used in the 86s

On my 86 I finally got fuel to the engine but, the return line had a small crack in it. And when I was messing with it , trying to get a small clamp on it. The complete end broke off about 3 inches from the end.

[Gary Lewis]

I recently went through this on Big Blue.  I ordered:

Dorman 800-072 3/8 in. Nylon Fuel Line - Black, 25 ft.  If I remember correctly the supply is 3/8" and the return is 5/16".  However, I used 3/8" on both and the 25' was just enough to make a whole new system.  But I had to get the right connectors.

Dorman 800-084 Fuel Line Quick Connector for 5/16 In. Steel to 3/8 In. Nylon Tubing, Pack of 2:  This fit the 5/16" steel tubing but used the 3/8" nylon tubing.

Dorman 800-082 Fuel Line Fitting for 3/8 In. Steel to 3/8 In. Nylon Tubing, Pack of 2: This fits the 3/8" supply steel tubing to the 3/8" nylon tubing.

Dorman 800-301 Fuel Line Repair Tool: This wasn't absolutely necessary as with a hot air gun you can probably get a good joint of the nylon line on the fittings, but it made it easier and more sure to get a good connection.

[jdavidsmi]

Thanks Gary, got it on order.

[jdavidsmi]

So I got the fuel lines in, a new reservoir, and a new high pressure pump. I know the pumps are running , but I still was not getting fuel to fuel rail.

I have put 10 gallons of gas in it, so I know it has gas.

I would disconnect the fuel lines a different points to see if gas was at that point. After disconnecting the line from the tank at the reservoir gas would run out but not under pressure.

I left the line disconnected and went to the house for a bottle of water, when I got back the gallon jug I was using as a catch for the fuel was all but full. Key was off . But gas was running out, I quickly raised the fuel line up above the tank to stop it. Thinking to myself, what the!.,,.? What is pushing the gas out. I open the fuel tank fill cap and air rushed in and the gas stopped running out.

So now I’m looking for a new vent vapor valve.

[jdavidsmi]

Well guys I have found the problem, the PO had replaced the high pressure pump, I did not know it. When I was not getting fuel to the engine, but I knew both pumps were running. I replaced the high pressure pump and installed it just as the old one came out. What I did not know was the PO had installed the pump backwards. So while the tank pump was pushing gas to the reservoir, the high pressure pump was pushing air into the reservoir and tank.. thus no gas to engine.

I found this by removing each pump, making sure it would pump gas. When the high pressure pump was not and it being new , and I could hear and feel it running. I check the wiring and it was correct. So just because I turned the pump around and it started pumping. So I hooked everything back up and primed it 4 or 5 times the motor fired up. It died right way so I primed it a couple more times, it started and ran, warmed up enough and idle down. Started it a couple more times.

Over the next couple of days I will put it back together, and take it for a spin.

[Gary Lewis]

Excellent!!!  That’s an easy fix to a serious problem.