Fuel pipe connection on Tank

[ian2000t]

I'm going to upgrade all of my fuel lines to 10mm, over the stock size (seems to be 6mm).

How does the fuel line connect to the tank? Is it just a banjo fitting like all of the connections to pump/filter in the engine bay?

Where do you get to the tank connection? Under the car, or from inside the boot somewhere? It's a UK 760 TD estate.

[v8volvo]

The lines connect, on my 1980s 740s, at the upper rear of the tank. Accessible from under the car, or via an access panel in the trunk/back seat somewhere (I have seen the panel from below but have not attempted to access it from above). The connection at the tank is a simple push-on hose over nipple with a hose clamp. To fit a larger hose, you will probably need an adapter, or sometimes I have had good luck making a sort of "sleeve" for the nipple by forcing a piece of appropriate size nylon tubing over it. I assume all this is the same on your 1990 wagon, though I cannot say for sure... someone else on here was just saying the other day that the fuel tank and filler setup changed in the late 1980s so yours may be different from mine. I have only ever worked with 1986 and older diesels so cannot speak to any late-production differences...

Why are you increasing the hose size?

[ian2000t]

Cheers, I will have a look. Basically I'm increasing the hose size because of running Veg oil. The fuel heating is done in the engine bay (when the coolant is warm), so will still be thicker than standard diesel (even blended with RUG) in the fuel tank and fuel lines. The lines look to be 6mm standard which isn't very big really.

In the cold weather approaching 4500rpm I can feel it intermittently holding back on veg (not on dino) - only since I've turned the fuel up, so that tells me that the lift pump (in the VE) is struggling somewhat. Larger fuel lines should help that considerably (hopefully eliminate it). Failing that I might look into a Facet pump.

[piper109]

There is about a 3/8" pipe going from the bottom of the tank with a spring and a strainer. It goes through the round flange for the big round hole in the top of the tank and forms an elbow for a rubber hose and clamp. You could easily remove that hard line, fit a larger dia elbow and run a larger dia hose to the bottom of the tank as well as a larger line to the front of the car. I also have run my car on veg but with a 2 tank system. The second tank is for veg and has a heater inside it to heat the oil with hot coolant diverted from the oil cooler circuit. Its slow to heat as the engine tends to run cool anyway.

Steve

[piper109]

Seeing as your car is 1990, it probably does not have what I described before. I converted a 1992 petrol car and it did not have a banjo fitting on the tank unit but still had elbows for the fuel lines (short rubber lines with clamps).

Steve