Daily Driver Eccessive Diesel Consumption, 407 With 2.0 Hdi

[B1ack_Mi16 67]

Hi

 

I've got an issue on my daily driver that I bought not long ago.

 

It always consume much more fuel than the onboard computer calculates.

 

Last weekend I was doing some long distance driving, 450km's each way.

The computer figure out I had used 57.65mpg on the trip (this is about the same as my old 405 TD used on the same type of driving), which I think is a reasonable figure for this type of driving.

 

Anyway the real consumption after topping up the disel tank showed to be 40mpg.

 

The same is valid for my more daily driving to work and the garage etc. where the computer figure is around 45mpg, while the real figure is more like 33mpg.

 

I'm suspecting the injectors to be the fault, as I think the calculated consumptions by the computer looks reasonable when I compare to the economy I get using my 405 TD for the same driving.

 

Have anyone had this big deviation between real world values and calculated ones?

It's like 10 litres of fuel is getting lost somewhere during just 1 week of normal driving, and it surely ain't no leak from the car.

 

The car starts absoloutely fine and it also idles nice without any signs of something wrong.

 

I need all the help I can get

[welshpug 1,666]

I would also be inclined to test the injectors, you can do a leakoff test on the HDI injectors.

 

 

Edited June 13, 2012 by welshpug

[B1ack_Mi16 67]

Been looking at those kits, but price is a bit high. But think I have found a kit for about 120£ locally now so might just go get that.

 

Anyway, how do one know how much diesel is supposed to come out of the return?

 

I suppose if my engine uses so much fuel one of more injectors would give very little return flow?

 

Looking on youtube it seem like the faulty injector in the leak-off tests usually gives a lot of return flow, but then I suppose less is going into the cylinder, or isn't that necessarily correct?

 

Might be better off dropping a XUD into the 407

[welshpug 1,666]

It seems the ones that flow more to the return are the damaged/faulty ones, not sure why this is, but the ecu may be increasing the duration or rail pressure to compensate?

 

not sure specifically how much is meant to come back, but similar to a compression test its variation you are mainly looking for, I think something like autodata or peugeot data may give the leakoff figures though.

[B1ack_Mi16 67]

I bought the kit for measuring return flow from the injectors and that resulted in this after about 10minutes of idling.

 

I actually don't think the deviation was that big, but I guess if one or more injectors are leaking that would be #1 and #3 then as they return less diesel?

 

 

Went into PP2000 and checked out the injector correction, and they all seem to be the same, more or less 100%.

 

 

This car is really killing me, doesn't really get any proper time for the T16 project or the 205. I guess that's for having a more modern car :/

[pugdamo 111 2 Cars]

The fuel that flows back through the return should be minimal,the fuel that returns is fuel that is used to cool the injector.

Each manufacturer has different procedures for checking leak back so you would need to do a little research for the proper method but if i cannot find out i would just run it on idle for about 3 minuites and compare each of the bottles,as welshpug says the faulty ones are the ones that return more,the ones i have diagnosed in the past are very obvious when they are knackered,iv never ran one for as long as 10 minuites but there doesn't seem to be a massive amount of difference as you have said. If you get on with your local peugeot dealers give them a call and see if they will tell you the procedure.