TD5 engine cranks over but wont fire up

[ES4]

Hi, My td5 engine cranks over but wont fire up, not even trying. Suspected the crank sensor but the engine ecu shows a rpm when cranking so I assume its OK. Rev counter is dead but I picked up on the following in the Rave.
The tachometer, which is located to the left of the speedometer in the instrument pack, displays
engine speed between 228 – 6,000 rev/min. Below 228 it receives diagnostic pulses only.
If I don't turn the ignition off and keep trying cranking it will not start. However 1 cycle of the ignition switch on/off and it starts straight away. It seems as though something is been reset. I don't think its fuel because cycling the ignition switch wouldn't suddenly provide fuel pressure. The Pump primes up every time. What is been reset ? Thanks

[Tins]

Hi, My td5 engine cranks over but wont fire up, not even trying. Suspected the crank sensor but the engine ecu shows a rpm when cranking so I assume its OK. Rev counter is dead but I picked up on the following in the Rave.
The tachometer, which is located to the left of the speedometer in the instrument pack, displays
engine speed between 228 – 6,000 rev/min. Below 228 it receives diagnostic pulses only.
If I don't turn the ignition off and keep trying cranking it will not start. However 1 cycle of the ignition switch on/off and it starts straight away. It seems as though something is been reset. I don't think its fuel because cycling the ignition switch wouldn't suddenly provide fuel pressure. The Pump primes up every time. What is been reset ? Thanks

Three questions: does the MIL ( check engine ) light up? And when it starts after cycling the switch does it run normally? Do you have access to a Nanocom?

[ES4]

Hi, No MIL Light, Runs normally. Used Lynx Diagnostics no fault codes. Thanks

[shack]

Hi, No MIL Light, Runs normally. Used Lynx Diagnostics no fault codes. ThanksBut does the little red light at the bottom of the dash come on/flash etc?

[ES4]

Hi, Do you mean the immobiliser led, I believe if it had not received the correct code then it would not crank. the light does go out after unlocking with the fob.

[shack]

Yep.


They'll definitely kick over though.
I'd see if that light behavior changes between ignition cycles.

Dodgy inertia switch could also be worth looking into.

Cheers
James

[ES4]

Hi, I unplugged the inertia switch and it still cranks as you said, but it sets the hazards away so I don't think its that. Red led for immobiliser pattern stays the same. I have always started it the same way ignition on and straight into crank. What I am doing now is turning the ignition on wait until the fuel pump times out (20s) and then cranking and it starts first time. It could be taking longer to pressurise the fuel system ?

[shack]

Hi, I unplugged the inertia switch and it still cranks as you said, but it sets the hazards away so I don't think its that. Red led for immobiliser pattern stays the same. I have always started it the same way ignition on and straight into crank. What I am doing now is turning the ignition on wait until the fuel pump times out (20s) and then cranking and it starts first time. It could be taking longer to pressurise the fuel system ?Ok, so when it does start does it run rough AT ALL ? Even a little bit?

[Bazzle218]

Years ago when i did my 2000 d2 injector washers, it would wind but not start. starter was winding over well. Long story short turned out battery was on the down side, plenty of omph to wind her over but not enough to kick in the ecu. Was at wits end so fitted new battery and away it went . Check your battery .

[ES4]

Hi, Engine sounds the same as its always done once its started, Battery is 3 years old and tests at 70%. i will order a replacement just to eliminate it. I might remove the fuel pump relay to allow the engine to crank but not start and look at this crank position sensor as I have read it can become corrupted by the starter motor inducing a field into it or the wiring. LR have screened the cable from the sensor to the ecu for a reason. I am still convinced it electrical but I may be wrong. Its difficult at the moment as it an intermittent fault, so I am trying to re-create it so I can get some testing done. I always find doing diagnostics better than just throwing parts at it. Fortunately I have access to a second vehicle so I am in position to do this.

[shack]

Hi, Engine sounds the same as its always done once its started, Battery is 3 years old and tests at 70%. i will order a replacement just to eliminate it. I might remove the fuel pump relay to allow the engine to crank but not start and look at this crank position sensor as I have read it can become corrupted by the starter motor inducing a field into it or the wiring. LR have screened the cable from the sensor to the ecu for a reason. I am still convinced it electrical but I may be wrong. Its difficult at the moment as it an intermittent fault, so I am trying to re-create it so I can get some testing done. I always find doing diagnostics better than just throwing parts at it. Fortunately I have access to a second vehicle so I am in position to do this.Generally speaking the ones I've seen that had unusually "noisy" starter motors that caused very poor starting, would indeed start in a similar fashion to what you speak of, but would not be as exactly repeatable as you have described, they also throw a "noisy crank signal" error, so you should have seen that if it was an issue.