Unusual needle RPM - diesel

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kapilamuni

Active Member
Posts
550
Hi,
My car got a random hiccup when idling. Hence the idle RPM is set at 819 not 750 , to avoid engine stalling in traffic.
With NANOCOM got the following data (hot engine ,stationary car) and it appears that the needle RPM goes below the idle RPM . The issue is that observed random hiccup was never there when these were recorded.
The needle lift sensor injector is new , genuine part installed recently, about 1000 KM ago.

NANOCOM - EDC.APP - EDC inputs SWITCH file
Idle (rpm);low Idle (rpm);Needle (rpm);Crank speed (rpm);Road speed (kmh);Road speed (mph);ELAB;Alarm status (on/off);Primary brake (act./ina.);Secondary brake (act./ina.);Aircon requested (yes/no);Aircon grant (yes/no);Clutch (yes/no)
HIGH;HIGH;1069.25;1160.25;0;0;HIGH;;LOW;;LOW;LOW;
LOW;HIGH;1001.00;978.25;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1069.25;1001.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;864.50;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;955.50;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;2752.75;819.00;0;0;HIGH;HIGH;HIGH;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;955.50;1046.50;0;0;HIGH;HIGH;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;955.50;864.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1183.00;1137.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;1501.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1183.00;1228.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1046.50;978.25;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1160.25;1296.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
LOW;HIGH;295.75;1274.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1137.50;1069.25;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;659.75;1296.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1092.00;1023.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;887.25;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;955.50;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;955.50;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1274.00;1228.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;978.25;864.50;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1001.00;887.25;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;887.25;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;864.50;796.25;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;432.25;864.50;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
 
Hi,
My car got a random hiccup when idling. Hence the idle RPM is set at 819 not 750 , to avoid engine stalling in traffic.
With NANOCOM got the following data (hot engine ,stationary car) and it appears that the needle RPM goes below the idle RPM . The issue is that observed random hiccup was never there when these were recorded.
The needle lift sensor injector is new , genuine part installed recently, about 1000 KM ago.

NANOCOM - EDC.APP - EDC inputs SWITCH file
Idle (rpm);low Idle (rpm);Needle (rpm);Crank speed (rpm);Road speed (kmh);Road speed (mph);ELAB;Alarm status (on/off);Primary brake (act./ina.);Secondary brake (act./ina.);Aircon requested (yes/no);Aircon grant (yes/no);Clutch (yes/no)
HIGH;HIGH;1069.25;1160.25;0;0;HIGH;;LOW;;LOW;LOW;
LOW;HIGH;1001.00;978.25;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1069.25;1001.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;864.50;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;955.50;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;2752.75;819.00;0;0;HIGH;HIGH;HIGH;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;955.50;1046.50;0;0;HIGH;HIGH;HIGH;LOW;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;955.50;864.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1183.00;1137.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;1501.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1183.00;1228.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1046.50;978.25;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1160.25;1296.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
LOW;HIGH;295.75;1274.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1137.50;1069.25;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;659.75;1296.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1092.00;1023.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;887.25;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;955.50;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;955.50;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1274.00;1228.50;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;978.25;864.50;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;819.00;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;1001.00;887.25;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;887.25;841.75;0;0;HIGH;HIGH;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;864.50;796.25;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;432.25;864.50;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;819.00;841.75;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW
HIGH;HIGH;841.75;819.00;0;0;HIGH;LOW;LOW;HIGH;LOW;LOW;LOW

Have you set the static correctly yet?
 
Don't really understand these things but I dropped your readings into Excel and this is what I see (file attached).

The idle shows more HIGH than LOW but then you said you'd set it high to stop it stalling. Mine is pretty much 50/50.

The difference in revs measured by the needle (#4 injector) compared to the crank can be quite large. With a warm engine just idling mine is never more than 25 different and usually 0. Your crank speed looks more consistent although if you blip the throttle they will go out of whack a bit.

Looks like you touched the brake pedal at one stage?
 

Attachments

  • EDCliveSwitches_20170807.zip
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Thanks Grrr for that Excel sheet.
Yes, the 4th injector is new, Bosch part.
No, I could not set static timing correctly.
But the 4th injector reading going so low below the idle RPM and it has no visible effect baffles me
 
Thanks Grrr for that Excel sheet.
Yes, the 4th injector is new, Bosch part.
No, I could not set static timing correctly.
But the 4th injector reading going so low below the idle RPM and it has no visible effect baffles me

If you blip the throttle they fall out of sync a little before the needle catches up. If the wire was a little dodgy inside it might lose the signal momentarily. With no signal from the needle I think it just runs on default values from the crank sensor. Either way the Nanocom is sampling maybe once a second so you are looking at a series of snapshots, not a continuum, so maybe the needle reading is only gone for milliseconds at a time in which case the car probably won't notice. Most of the time yours is pretty close - check the average difference value.
 
Thanks Grrr for that Excel sheet.
Yes, the 4th injector is new, Bosch part.
No, I could not set static timing correctly.
But the 4th injector reading going so low below the idle RPM and it has no visible effect baffles me

You need to get the static timing set correctly. You have either got the bottom chain in the wrong position on the sprockets or the injection pump has serious internal mechanical problems. RPM is measured by the CPS, the ECU extrapolates TDC by measuring the time difference between two timing pips, one 40 degrees before top dead centre and one 20 degrees after top dead centre, so the ECU knows where TDC is. The number four injector tells the ECU the point of injection, if this differs from TDC as extrapolated from the CPS the ECU modulates the timing device solenoid to reduce or increase internal fuel pressure being applied to the timing device piston against spring pressure, to move the stator cam to advance or retard the point of injection to match TDC. This is ONLY measurable with engine up to full temp, engine idling at 750 RPM, when modulation should be between 45% and 55% and the point of injection within 1 or 2 degrees of TDC and the CPS and needle RPM within 40 RPM of each other. It is totally pointless asking questions like that until you get the static timing correct and idle is set at 750 RPM. Basically you are looking at a cracked mirror and wondering why the image is distorted.
 
I know what you are telling me Wammers.
Despite everything else is out of line, should the 4th injector output go as low as 295 RPM?
Does anyone else experience such low values from the 4th injector?
Ans I can remember there was a comment on RPM going below 500 and engine stalled by ECU. Should not it happen here?
 
As I can remember there was a comment on RPM going below 500 and engine stalled by ECU. Should not it happen here?

I am not sure how many readings it requires in a row to stall or whether it requires the needle or the crank or both to be low before it cuts the fuel. Clearly in this instance it either isn't low enough for long enough or it takes the crank as default. Or maybe it does momentarily shut the fuel and the engine will seem to be running rough.

I think you'd have to take a trace to spot values as low and brief as that. Not many people take traces of that screen. I tend to tinker a bit!
 
I believe he is listening, but for reasons known only unto himself he is chasing false shadows.
If I ever have a problem that may be known to Wammers I will only argue the toss for maybe 2 posts then surrender,
you can't argue with experience.
 
Only option is to replace the pump. That's very expensive at the moment.

Forgive me for asking this, but if the engine is running reasonably well other than stalling when set at 750 RPM how is changing the pump going to correct static timing. The pump internals would have to be seriously worn to prevent static being achieved IF the bottom chain is in the correct place. So worn in fact that getting the engine to start at all would be a minor miracle.
 
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