From where you have tapped at the moment what type of pulse/signal do you get? Then check what you get from the crank sensor
.J
P38A Thor engine RPM
- Thread starter kermit_rr
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From where you have tapped at the moment what type of pulse/signal do you get? Then check what you get from the crank sensor
.J
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Thats news to me thank you
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that's getting above my pay grade! What do you mean, what sort of signal do i get? An electronical one I'd hopeFrom where you have tapped at the moment what type of pulse/signal do you get? Then check what you get from the crank sensor
J
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With the disparity between meaurements, I would suspect that one is engine revs and the other is crank revs
Marshall8hp
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Can someone explain to me the difference between engine revs and crank revs? I thought engine revs was the number of times the engine crankshaft went around in a minute. So what is/are "crank revs"?
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Engine revs and crank revs are the same. Neither are a complete 4 stroke cycle, which requires 2 revs.
When an engine is doing 1000rpm it has completed 500 4 stroke cycles in a minute, per cylinder or 4000 per v8 engine
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I'd have thought the rev counter comes off a cam sensor as the spark is redundant, although I guess there could be a multiplier for #1 spark or even crank sensor. I guess it could even use the injector pulse somewhere. Knowing Land Rover I could even see the BECM takings lots of inputs, calculating an average and then the BECM sending a signal to the instrument cluster.
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from the Motronic guide, "...engine speed is measured using the crankshaft sensor and sensor wheel"
tomcat59alan
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ah yes, I do like a nice straight 6, lovely engines
tomcat59alan
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Oh yes,we had a 325I ,it was fantasticly fast, the M51 is a nice engine as well.ah yes, I do like a nice straight 6, lovely engines
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i had one of them too and yes very fast! mine was the e36 with m50 engine. i got a later 328i with the m52 engine but it didnt feel anywhere near as fast and certainly more wheezy with the crap manifold, swapping the m50 manifold was a popular choice, i never did it though
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someone at BBS is going to check with the devs, see whats going on and see if I can be enlightened
Can we just get a few things clarified.
1. the engine runs and idles fine on petrol.
2. the engine runs and idles fine on gas.
3. the idle speeds on the Nano/gas system(laptop)/Rev counter all shown the same.
4. When was the last time you updated your Nano, would it make a difference.
From what I have looked at and can work out from your many musings. The pin you piggy backed onto at the ECU is it the 1 that goes to the BECM/IP?
For petrol that is 4 pulses/RPM (if I see it) not sure what that would mean or do.
What does the Crank sensor put out as there is a number of tangs (cant remember how many) but has 1 gap for reference for the ecu to know 1 revolution/where it is.
If the engine runs and Idles on petrol and LPG, then ignore all my waffle. and don't touch anything.
J
1. the engine runs and idles fine on petrol.
2. the engine runs and idles fine on gas.
3. the idle speeds on the Nano/gas system(laptop)/Rev counter all shown the same.
4. When was the last time you updated your Nano, would it make a difference.
From what I have looked at and can work out from your many musings. The pin you piggy backed onto at the ECU is it the 1 that goes to the BECM/IP?
For petrol that is 4 pulses/RPM (if I see it) not sure what that would mean or do.
What does the Crank sensor put out as there is a number of tangs (cant remember how many) but has 1 gap for reference for the ecu to know 1 revolution/where it is.
If the engine runs and Idles on petrol and LPG, then ignore all my waffle
. and don't touch anything.J
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i have disabled RPM input on the LPG ecu, so its calculating from ignition timing. When RPM measurement was enabled, it was seeing 4x RPM not actual RPM, I didnt dare switch to LPG
the nanocom is on the latest 1.35
yes, the wire i piggybacked is the one which comes from the bosch ecu. why would there be 4 pulses/RPM?
I've not measured the crank sensor output, dunno how to do that
it does run OK at the mo, but i'd like to know whats going on, purely from a knowledge point of view. If there IS something wrong then I'd like to fix it, or at least know why, in case it causes issues later down the line
the nanocom is on the latest 1.35
yes, the wire i piggybacked is the one which comes from the bosch ecu. why would there be 4 pulses/RPM?
I've not measured the crank sensor output, dunno how to do that
it does run OK at the mo, but i'd like to know whats going on, purely from a knowledge point of view. If there IS something wrong then I'd like to fix it, or at least know why, in case it causes issues later down the line
Tachometer
The tachometer will display the engine speed in
RPM. It will derive the engine speed from the
engine speed pulse train transmitted from the Engine
Control Module (ECM) (Z132).
The pulse rate for petrol engines will be 4 pulses per
engine revolution.
The pulse rate for diesel engines will be 3 pulses per
engine revolution.
INSTRUMENTS III
Audible Warning
Receipt of an audible warning request signal from a
vehicle parameter/message condition shall cause the
BeCM (Z238) to generate the required number of
warning tones. The actuator sounder unit is located
at the rear of the Instrument Cluster (Z142).
From the manual.
I understand wanting to fix/get it right.
So maybe the input side of the ECU is what you need (crank sensor)
Did you say there was 2 settings on the gas weak & strong?
Wonder if you need weak as the gap goes by it drops the pulse/voltage more.
J
The tachometer will display the engine speed in
RPM. It will derive the engine speed from the
engine speed pulse train transmitted from the Engine
Control Module (ECM) (Z132).
The pulse rate for petrol engines will be 4 pulses per
engine revolution.
The pulse rate for diesel engines will be 3 pulses per
engine revolution.
INSTRUMENTS III
Audible Warning
Receipt of an audible warning request signal from a
vehicle parameter/message condition shall cause the
BeCM (Z238) to generate the required number of
warning tones. The actuator sounder unit is located
at the rear of the Instrument Cluster (Z142).
From the manual.
I understand wanting to fix/get it right.
So maybe the input side of the ECU is what you need (crank sensor)
Did you say there was 2 settings on the gas weak & strong?
Wonder if you need weak as the gap goes by it drops the pulse/voltage more.
J
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thanks, I'd not seen that in my excavations of books and guides.Tachometer
The tachometer will display the engine speed in
RPM. It will derive the engine speed from the
engine speed pulse train transmitted from the Engine
Control Module (ECM) (Z132).
The pulse rate for petrol engines will be 4 pulses per
engine revolution.
The pulse rate for diesel engines will be 3 pulses per
engine revolution.
INSTRUMENTS III
Audible Warning
Receipt of an audible warning request signal from a
vehicle parameter/message condition shall cause the
BeCM (Z238) to generate the required number of
warning tones. The actuator sounder unit is located
at the rear of the Instrument Cluster (Z142).
From the manual.
I understand wanting to fix/get it right.
So maybe the input side of the ECU is what you need (crank sensor)
Did you say there was 2 settings on the gas weak & strong?
Wonder if you need weak as the gap goes by it drops the pulse/voltage more.
J
I've tried weak and strong, both give the same value. I wonder why its 4 pulses, something to do with error correction?
sounds like piggybacking the crank sensor is the next option.. at worst it can only be wrong or not readable
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4 pulse/rpm for petrol, 3 for diesel. They are both 4 stroke, i need to know why they are different other than *reasons*
other than *reasons*4 pulse/rpm for petrol, 3 for diesel. They are both 4 stroke, i need to know why they are different
Have you got a diesel?
EDC is different in a lot of ways I am lead to believe.
I dont really care
that much to take up valuable grey matter space.J
