Fuelling - injected quantity and start of injection advance

myfirstl322 said:

there is no emoticon to portray my hand brushing past my head and making a whoosh noise...

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mcapinha said:

Today, after a little run with the Hawkeye connected, I got curious about the fueling information. My DSE always seemed a little bit thirsty, compared to some reports around here, doing at best 22mpg when driven sensibly.

I have no clue on how to interpret these. Can someone help ?

When these were taken the engine was at idle, around 750rpm (sometimes droping to 728rpm), at normal running temperature (around 85º), outside air was at 20ºC and diesel temperature was around 50ºC.
The injected quantity reading was pretty stable but the "Start of advance" was moving between 0º and 1º. Is this supposed to be normal ?

I'm not trying to find a problem where there is none just curious on how to interpret these readings.

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wammers said:

Yes, if the fuel quantity was any less the engine would slow if it was any more the engine would speed up. Other reading is feed back from number four injectior. If 22 MPG is around town that is not shabby. You should see the high twenties on a steady motorway run above 50 MPH. Look for timing modulation on diags should be around 45% to 55%. Ideally 50%, any less than 45% pump static is advanced any more than 55% it is retarded.

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mcapinha said:

Unfortunately Hawkeye doesn't provide timing modulation info, that's why I posted the images above, in hope that there was some conclusion that could be reached.

Does the Nanocom provide this information ? I have a friend with one of those, could try hooking it up and see what it shows.

Looking back at my log book, my latest averages (brim to brim) are of 25mpg, 26mpg and 22mpg. The 26mpg one was a mix of highway travel and country roads at a slow pace, the other ones are mixed driving, so this isn't looking too bad.

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· Timing modulation (%): This value is the amount of percentage change that the EDC
· ECU applies to the injection timing. It can be checked in conjunction with the Injection
set points and actual values. On a fully warm engine this value should steadily remain
between 45% and 55%. There should be no erratic fluctuations.

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mcapinha said:

So, I finally managed to get my DSE checked with a Nanocom evolution.

The timing modulation, after the engine's at a proper temperature, is around 49% but it jumps up and down a little bit at idle (i'd say between 47% and 52%).

Nanocom's guide says this:


What do they mean with "erratic fluctuations" and "steadily remain between..." ? I wouldn't consider the fluctuation that I'm watching erratic but it's not exactly steady either ? :scratching_chin:

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mcapinha said:

Great info as usual Wammers.
So, if the timing modulation is looking good, can I assume that the static timing is ok ?
And, since I have the usual hot start problem, can I then assume that it's down to FIP wear?

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mcapinha said:

Great info as usual Wammers.
So, if the timing modulation is looking good, can I assume that the static timing is ok ?
And, since I have the usual hot start problem, can I then assume that it's down to FIP wear?

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