Diesel cranking but not firing

[Ducati750cc]

Originally Posted by Mats

A good friend came to the rescue and helped with the diagnosis: the in-tank fuel pump has gone.

My faulty front offside ABS sensor played up the fuel gage so it was harder to initially diagnose.

Both will be repaired shortly

Just wondering, how did /could a problem with the ABS sensor affect the fuel gauge?


Intrigued !

[MarkS]

A short in the instrument pack wiring ?

[Popcorn]

Originally Posted by Ducati750cc

Just wondering, how did /could a problem with the ABS sensor affect the fuel gauge?


Intrigued !

Had this on my tourer,fuel gauge rising and falling slightly and speedo not working turned out to be f/o/s abs sensor, apparently because the car can't work out fuel consumption by the computer the gauge rises and falls .so I'm led to believe sure i read it in a post on here a while back.

[marinabrian]

Originally Posted by Ducati750cc

Just wondering, how did /could a problem with the ABS sensor affect the fuel gauge?


Intrigued !

The fuel gauge in the IPK is fed by two fuel level senders, each made up of a float and variable resistor. The senders are connected in series and if any fault occurs in this circuit the gauge defaults to zero and the low fuel warning lamp is illuminated.

However, if either of the senders fail during an ignition cycle, and this can take the form of a momentary glitch from one of the variable resistors, the fuel gauge is then driven by the fuel consumption signal received from the ECM via CAN-Bus, which in itself is derived from various inputs, including the road speed signal from the right hand front wheel, at a rate of 39000 pulses per mile in a square wave signal from the ABS modulator.

When the ignition is turned ’off’ and back ’on’ again the low fuel lamp will illuminate and the gauge will default to zero, however if there is a signal present from both senders, it will assume an average based upon the previous usage pattern.

The IPK performs complex algorithms on the signals from the senders to ensure the correct level is calculated, this is mainly to compensate for the saddle design, and to accommodate "slosh" damping.

Mats car had a fuel gauge sender fault logged in the IPK, the OS/F ABS sensor showed a line fault, and there was an indicated 1/4 of a tank of fuel.

The addition of 5 litres of fuel resulted in a LP delivery pressure of 3.5 Bar, meaning the priming port of the inoperative ITP was no longer exposed.

So the gauge had previously artificially shown more fuel, but after resetting, it settled at just under the 1/4 mark.

A collective of seemingly unconnected faults, that when put together resulted in a breakdown.

That's how I explained the problem to my friend after we rescued his car from the side of the road.

Now my memory isn't quite what it was when I last was tested on the inner workings of the IPK, so I'm happy to somebody to independently clarify this.

[Arctic]

Hi Mat.
Now i know whom your friend is and he explained to me your car had a defective ITP, and the UBP was sucking air, ( The IPK takes the average of the two senders in the tank, and uses an "anti slosh" algorithm coupled with the road speed input and engine load input, to calculate the remaining fuel.)

His words in the brackets which he told me through an email, i doubt anyone else would have found that out except your friend and mine whom i also to.

[BigRuss]

Undo underbonnet fusebox and unlatch and remove all the connectors a couple of times to clean up the contacts, see if that cures it

Russ

[Typhoon190]

Evening all.

My diesel has been off the road for a while undergoing quite a bit of repair work. I am in the last stages of putting it back together, and wanted to run it today but seem to have no action from the fuel pump in the tank.

I replaced the engine bay pump which is operating but car won't start.

Fuse 20 appears intact. Car was running prior to work, so guessing it needs a replacement in tank pump.

I can't find a wiring diagram to find out which wires to check on the wiring plug for the in tank pump to check it receiving power. Can anyone point me in the right direction please?

Thanks in advance. Ben.

[Yorkshire GOC]

As to wiring diagrams i would advise getting a RAVE disc see link below - as far as i am aware it has the most comprehensive set of electrical data for our cars - only a tenner or so. Just be aware to run on Windows 10 there is a workaround on the site somewhere.

https://rimmerbros.com/Item--i-ZAA000400

[Yorkshire GOC]

There you go pre facelift fuel pump wiring - sorry image is not great but this gives you an idea what RAVE contains.

[Typhoon190]

Thanks Martin.

I may have jumped the gun a bit and bought this.

https://www.ebay.co.uk/itm/304167520855

I'm planning to will it in to place.