Td5 fault reader needed around blackpool

johnlad said:

thanks Sierraferry,
just remembered also said that i have an idle speed error of +30-40rpm, with engine idling around 775 rpm,
would that be related to the injectors also

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johnlad said:

to test the injector, im thinking if i swop it with another cylinder roughness should move to that cylinder? if not then is it the wiring harness

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Crankshaft speed and Position (CKP) sensor
The CKP is located in the transmission housing with its tip adjacent to the outer circumference of the flywheel. The
CKP sensor works on the variable reluctance principle, which sends a signal back to the ECM in the form of an ac
voltage.
The ECM uses the signal from the CKP for the following functions:
l To calculate engine speed.
l To determine engine crank position.
l To determine fuel injection timing.

The CKP sensor works as a Variable Reluctance Sensor (VRS). It uses an electromagnet and a target ring to generate
a signal. As the target ring passes the tip of the CKP sensor the magnetic field produced by the sensor is cut and then
re-instated. The ECM measures the signal as an ac voltage.
The outer circumference of the flywheel acts as the target ring for the sensor. The flywheel is divided into 36 segments
each of 10. 31 segments have drilled holes and 5 segments are spaces. This equals 360 or one engine revolution.
The 5 spaces correspond to the TDC position of the 5 cylinders, this allows the ECM to control fuel injection timing
for each of the cylinders.

Input/Output
The two pins on the sensor are both outputs. The ECM processes the outputs of the sensor. To protect the integrity
of the CKP signal an earth shield or screen is used.
The ECM measures the outputs from the CKP. The ECM measures the positive signal from the CKP at pin 13 of ECM
connector C0158. The ECM measures the negative signal from the CKP at pin 36 of ECM connector C0158. The earth
path is via pin 16 of ECM connector C0158.
Voltage generation from the CKP sensor is relative to engine speed. The values expected from a good CKP sensor
are as follows:
l 2 to 3 volts with engine cranking.
l Rising to 6 to 6.5 volts from 1000 rev/min upwards.
The above readings are dependent upon correct air gap between the tip of the CKP sensor and the passing teeth of
the reluctor ring.

The CKP sensor can fail the following ways or supply incorrect signal:
l Sensor assembly loose.
l Incorrect spacer fitted.
l Sensor open circuit.
l Sensor short circuit.
l Incorrect fitting and integrity of the sensor.
l Water ingress.
In the event of a CKP sensor signal failure any of the following symptoms may be observed:
l Engine cranks but fails to start.
l MIL remains on at all times.
l Engine misfires (CKP sensor incorrectly fitted).
l Engine runs roughly or even stalls (CKP sensor incorrectly fitted).
CKP does not have any backup strategy and if it fails the engine will stop running and fail to start.

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johnlad said:

futher to this, ive had the crankshaft sensor out today, it was a bit grubby, so gave it a clean with contact cleaner, tested it with a multi meter, across the pins it had a resistence of 1.3 ohm, is that relevant?
anyway it started and smoked the same but drove a lot more lively,
any idea's anyone

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