fuel

The Fuel Gauge Reading

Instrument cluster readings on 18 December 2018.

You though that the fuel level display on the Scrubmaster should show you the fuel level, right? No. This is an Iveco vehicle, where NOTHING is simple if it can be made complex. It took Iveco 25 pages to show you what REALLY is being displayed. And that is said to be a work in progress!

The take-away message seems to be that the fuel gauge only updates reliably during fuel transfers if the ignition is turned off, the key is removed and then inserted and ignition turned on, and even then the fuel transfer must be more than 4 litres to show.

My experience is that when transferring fuel from the auxiliary tank to the main tank while driving (ignition on), the fuel gauge does update. This must be because the fuel transfer rate is sufficienty slow/close to what the ECU considers to be a possible instantaneous consumption that it accepts the changes.

Based on only a few long trip logs.

My experience is that the gauge is very unreliable at indicating minimum fuel level. The described algorithm claims that the display goes to zero when fuel level drops below 3 litres. My experience is that there can be over 20 litres left!

When travelling big distances between fuel points or when near empty its important to know what the fuel gauge is telling the driver. Here is a Table based on some log entries. I have never truely run out of fuel but the gauge needle has been BELOW E a couple of times! Always have a few 10s of litres of diesel in the auxiliary tank just in case!

Fuel Pre-filter

While well protected, the pre-filter bowl is easily checked for water.

Given the occasional reports of bad fuel in country regions and the damage it can do to common-rail diesel engines it is essential to have a filter with water trap that can be routinely visually inspected. The main diesel fuel filter on the Iveco 55S17W has a water trap and dash alarm. While that's good, it is not possible to inspect the water trap since it is enclosed in the black plastic filter holder and this is invisible behind the LH inner mudguard. It may also be too late when the alarm goes off.

I have installed a Stanadyne Fuel Manager F100 series Universal Water Separator/Filter model 42093 in front of the box for the camper battery on LH side of the chassis. It only takes a moment to check whether there has been any water captured, this can be drained out by loosening the black wheel at the bottom of the filter. As well as Stanadyne 30µm filter elements 31863, this Fuel Manager also accepts Donaldson part P551426. The element should be changed every 30,000km or more frequently if lots of remote travel.

Fuel Pre-filter Installation

There was a gauze pre-filter on TT30 but that seems rather useless. What was required is a quality pre-filter with water trap that can be routinely inspected.

The Stanadyne Fuel Manager model 42093 filter/water trap kit I purchased came with a universal housing and the correct barb fittings. The Stanadyne can easily pass the required 150 L/h and has a water separation efficiency of 95%.

I have chosen to mount the Filter on the front of the camper battery box using the supplied M10 bolts, washers and Nylock nuts. Because the battery does not completely fill the box, there is room to install the nuts without interference.

Discarding the Iveco pre-filter allowed me to reroute the supply hose from the fuel tank back towards the new filter. I needed a further 580 mm of 5/16" (7 mm dia.) fuel hose and a 1/4" brass hose joiner (P7-04) from a local branch of ENZED for the inlet to the filter. A 1400 mm length of fuel hose then goes from the filter outlet to the input line to the fuel pump using a second 1/4" brass hose joiner and worm-drive hose clamps.

On top of the fuel tank. Supply line goes to the left, return line goes to the right.

Fuel hose from the new pre-filter joins the OEM hose to the fuel pump.

Looking up at the new pre-filter with water trap bowl on the bottom.

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