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Bin neu hier
Mit dabei seit Anfang 2017 Wohnort: Silvaplana
...und hat diesen Thread vor 2607 Tagen gestartet!
| Fahrzeuge 1. 1998 Defender 90 TD5 |
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Verfasst am: 27.02.2017 05:25:53 Titel: Defender TD5 ecu timing |
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Hi, I have a question on my 98 Td5 defender, I have fitted my td5 with a new cylinder head. When taking apart, I inserted the locking pin at the camshaft and one at the transmission bell housing. I noticed that the two colored links by the mark at the timing chain sprocket were barely noticeable.
Before putting back together I made sure the two locking pins (bell housing and camshaft) were in place, I did not bother looking for the colored links though thinking that well if both locking pubs are inserted, the timing must be right...
Now I realize that I probably mixed up the compression with the exhaust stroke, because I did not see the two colored links at all, they were probably at the other end of the chain. Does this matter? The ecu sensor is on the flywheel. The flywheel spins once for the compression stroke of all cylinders and once for the exhaust stroke of all cylinders. How does the ecu know whether it's on the compression or exhaust stroke? Since the sensor is fitted on the flywheel, one entire revolution of the flywheel with the sensor passes for the compression stroke, another entire evolution with sensor passes on the exhaust stroke...
My ultimate question is: do I have to remove the cylinder head again, rotate the crankshaft one revolution, and refit the cylinder head?
Or will it run as is?
Look forward to any inputs...
Regard,
Jan | |
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Offroader
Mit dabei seit Anfang 2007 Wohnort: Alpenrod Status: Offline
| Fahrzeuge 1. Defender 90TD5 SW 2. Range Rover P38 4.6 |
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Verfasst am: 27.02.2017 07:55:05 Titel: |
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This will help you, it's from a technical document about the TD5:
Zitat: |
As previously mentioned, the crankshaft is drilled at 10 intervals and features 5 missing holes.
Because the missing holes are positioned at uneven intervals around the circumference of the
flywheel, the ECM is able to calculate the exact position of the crankshaft within each 360 of
rotation.
In addition to detecting the crankshaft position, the ECM is able to assess relative acceleration and
deceleration of the crankshaft, caused by a pistons compression cycle and firing strokes. This
function is explained in the section on diesel engine strategies.
The signal supplied to the ECM by the crankshaft position sensor is used to support its fuelling
strategy. The ECM also uses this signal to calculate engine speed and supplies this information
to a number of other vehicle systems. The ECM is also able to calculate the exact position of the
crankshaft relative to the firing position of the engine. This information is used to calculate the
exact point of injection.
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Oliver |
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Mit dabei seit Anfang 2017 Wohnort: Silvaplana
...und hat diesen Thread vor 2607 Tagen gestartet!
| Fahrzeuge 1. 1998 Defender 90 TD5 |
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Verfasst am: 27.02.2017 09:55:05 Titel: |
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Hi Oliver,
Thanks for your answer!
Ok BUT, when the flywheel goes around once, the intake and compression stroke for a particular cylinder is done. The flywheel needs to around a second time for the fire and exhaust stroke of that particular cylinder. So for the two revolutions of the flywheel, how does the ecu know which revolution is the intake/compression and which one is the fire/exhaust stroke for a particular cylinder?
The injection is done mechanically via the unit injectors over the rocker shaft. But what about the electronic signal from the ecu going to the unit injectors opening the solenoid valve to fill the unit injector with diesel before injection?
Regards
Jan | |
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Offroader
Mit dabei seit Anfang 2007 Wohnort: Alpenrod Status: Offline
| Fahrzeuge 1. Defender 90TD5 SW 2. Range Rover P38 4.6 |
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Verfasst am: 27.02.2017 10:27:54 Titel: |
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The ECU detects camshaft position by the uneven run of the crankshaft:
Zitat: | To ensure the ECM injects fuel at the correct time, it must know the exact position of the crankshaft
and the firing point of each cylinder. In a sequential conventional EMS system (where this
information is required), a camshaft sensor is used to provide the ECM with the firing point
information. The Td5 engine is not fitted with a camshaft position sensor. Therefore, the ECM used
on the Td5 engine employs a different strategy to identify the firing position of each cylinder.
In this application, the signal provided by the crankshaft position sensor identifies the exact
position of the crankshaft within each revolution. This information enables the ECM to determine
which one of the five pistons is approaching TDC at any given time.
In the Td5 diesel engine, the crankshaft speed ‘slows’ as each piston travels up the bore on its
compression stroke. The graph identifies the compression cycle over 720 ° of crankshaft rotation.
This characteristic allows the ECM to determine the firing position of the engine using the relative
acceleration and deceleration of the pulses within the engine speed signal provided by the
crankshaft sensor. |
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Oliver |
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Bin neu hier
Mit dabei seit Anfang 2017 Wohnort: Silvaplana
...und hat diesen Thread vor 2607 Tagen gestartet!
| Fahrzeuge 1. 1998 Defender 90 TD5 |
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Verfasst am: 01.09.2017 10:06:14 Titel: |
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Hi again,
in one of your previous posts, did you mean to say the flywheel is drilled at 10 DEGREE intervals?
You just wrote 10 intervals. Did you mean 10 degrees?
Thanks!
Kind regards,
Jan | |
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