Fuel Hose Shopping Guide

I apologize that this posting comes so long after this thread was started. I was unexpectedly away from my email for some time (and you wouldn't believe how many hundred Jag messages I had waiting!). Anyway, the purpose of this post is to detail the quantity of each size of fuel hose you need to buy in order to change all of the fuel hoses on the SIII XJ6. You can easily count the number of new clamps needed for the individual sections you are going the change, but since the fuel hose swells as it ages it is very difficult to know ahead of time what size hose and clamps to buy.

I'll start with the trickiest size. The three hose sections in the trunk leading from the two fuel tanks to the fuel changeover valve, and from the fuel changeover valve to the fuel pump inlet are 7/16 (seven-sixteenths) of an inch (all sizes given are for the inner diameter). I had some trouble finding this size--none of the three auto parts stores here in Moscow, Idaho, had it, but I was able to find it at one of the tractor dealers. Buy about four feet. It should be cheap, around a dollar (US) a foot. Note that this is the only fuel hose on the car that does _not_ need to be fuel-injection quality because it is not under high pressure.

The following sections are size 5/16 (five-sixteenths) inches: each of the 6 sections leading from the fuel rail to the fuel injectors; the section leading from the fuel rail to a metal connector tube; the very short section (located behind the fan) which joins one connector tube to another; and from the fuel rail to a sensor on the intake manifold.

Also, all of the hose sections in the trunk that come after the fuel pump are 5/16, with one exception noted below. This means from the fuel pump to the metal tube, from the metal tube to the non-return valve, from the non-return valve to the filter, and from the filter to the metal tube that leads up to the engine compartment. The exception is the return hose that leads into the _top_ of the non-return valve. This hose looks smaller and it is at only 1/4 (one fourth) inches. So, buy 1 package of 1/4 inches fuel-injection hose, and buy 4 packages of 5/16 inches fuel-injection hoses (the packages I bought were nominally 18" each).

The following hoses are size 3/8 (three-eighths) inches: the supply tube (coming from the trunk--this comes in on the intake side of the engine from underneath the car) to the fuel rail; from a metal connector tube on the exhaust side of the engine to the fuel cooler; and from the fuel cooler to the return tube (leading back to the trunk). Buy 2 packages of 3/8 fuel-injection hose.

As many other list members have already mentioned, be sure to buy fuel-injection hose, and replace all of the clamps with new ones. Like the hose, the clamps should be the special (and more expensive) fuel injection variety, and be sized correctly to match the hose. Watch out that the auto parts clerk really directs you to the fuelinjection hose. (One clerk tried to give me hydraulic hose.) None of the shops here sells it by the foot, only by the package. The packages cost about US 6 dollars each.

Changing all the hoses takes several hours, but it's extremely rewarding. Although it's not technically difficult (anyone can do it), there are a large number of hose sections. I cut off each old hose to save time on the removal, and I wore disposable latex examination gloves to keep my skin from getting dried out by the gasoline that spills from each hose section. A very sharp Buck-type knife is handy for cutting the new hose because it is just too tough to be cut easily with a standard utility knife. When you finally have the whole car done it is a good feeling to drive the car knowing that you won't pop a decade-old fuel hose and burn up your beautiful Jaguar.