:scratching_chin:Can anybody give me any help the timing chain snapped on my 2000 discovery replaced chain and sprockets, valves,seals and guides, rockers as they were all smashed, head is still straight which was a bonus, replaced head gasket and bolts, followed purge procedure and flattened battery about 5 times so far and had to replace starter as it burnt out can anybody think of any other reason to why it is not starting as I am scratching my head at the moment.
Bennehboy
Well-Known Member
Is it chucking fuel vapour out the exhaust?
They can take a while to prime once they've had no fuel in for a while.
Not sure how many times you tried the purge, but when I rebuilt my engine I think I had to do it 4 or 5 times. If it's not chucking fuel out the exhaust do another purge, then keep your foot to the floor whilst cranking, this tells the ECU to chuck more fuel into the pots...
If there's fuel being blown out the back then next bet would be to check the CPS sensor.
They can take a while to prime once they've had no fuel in for a while.
Not sure how many times you tried the purge, but when I rebuilt my engine I think I had to do it 4 or 5 times. If it's not chucking fuel out the exhaust do another purge, then keep your foot to the floor whilst cranking, this tells the ECU to chuck more fuel into the pots...
If there's fuel being blown out the back then next bet would be to check the CPS sensor.
The connecting rods are all straight the pistons and sleeves are all ok the pistons all reach top and bottom of travel the valves all open and close as they should will check to see if fuel vapour is coming from the exhaust. Can hear fuel pump running when purging and the can hear fuel coming from the injectors
Gearmuncher
Member
check compression, turn engine over by hand should be very hard at times, if compression ok, fuel is not being injected or being injected at the wrong time, the timing is created by the crank shaft sensor and the cam shaft sensor, if one of these is not working it will not know when to inject the fuel, also immobiliser may be stopping injectors to fire, I think there is a red light on the dash that will tell you if it activated, have to look in owners manual.
Gearmuncher
Member
also found this on another site, Thanks everyone, I did say I had fuel pressure at engine, but forgot it should be around 60psi. Off with tank again and stripped fuel pump. Found 1 carbon brush broken, shaft not running true and rotor binding on stator,which was full of fuel. Fitted new Genuine pump, bled, fired first time. Thanks again.
Bennehboy
Well-Known Member
There's only a crank sensor (CPS) on the TD5 as mentioned above, OP needs to check that it's functioning. The ECU works out all the injector timing from the signals coming back from this - including balancing for out of tolerance parts, it's quite smart really.
Someone like SierraFery on here can give the right electrical info for testing the CPS (or search the forum).
OP Should eyeball (and smell) the exhaust whilst cranking to see if fuel is being delivered.
sierrafery
Well-Known Member
immobiliser = no cranking so it's not that, i'm with Bennehboy on this, unfortunaltely to check crank signal a tester or oscilloscope is needed not doable with multimeter
Gearmuncher
Member
apparently there is no cam sensor on TD5, trying to work out how it knows which cylinder is at power stroke.
Bennehboy
Well-Known Member
From RAVE:
The CKP sensor 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 principal, which sends a signal back to the ECM in the
form of an ac voltage.
The ECM uses the signal from the CKP sensor for the following functions.
To calculate engine speed.
To determine engine crank position.
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 10deg. 31 segments have drilled holes and 5 segments are spaces. This equals 360deg 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.
sierrafery
Well-Known Member
...i was up to post that copy too but it's already there... i'd add this too:to check injector outputs from ECM also oscilloscope is needed
