2002 td4 turns over but won't start

Hi td4van.

Thanks for the coments.

You can read the output from it by cutting into the signal wire while the sensor is removed and then moving the sensor close to metal and away from it watching for a change in the voltage on a meter but I didn't want to start cutting into the cable.

mediaseller said:

Hi td4van.

Thanks for the coments.

You can read the output from it by cutting into the signal wire while the sensor is removed and then moving the sensor close to metal and away from it watching for a change in the voltage on a meter but I didn't want to start cutting into the cable.

Click to expand...

You can check the sensor is working by measuring the signal at the EDC end of the harness

mediaseller said:

Hi td4van.

Thanks for the coments.

You can read the output from it by cutting into the signal wire while the sensor is removed and then moving the sensor close to metal and away from it watching for a change in the voltage on a meter but I didn't want to start cutting into the cable.

Click to expand...

Yes I know but that’s not in its natural environment and doesn’t prove that it’s picking up the right signal from the cam and transmitting it to the ECM

C0606 is the middle connector of the ECM. You can see the pins for CMP (cam) signal and earth, and CKP (crank) signal and earth.

CMP - Hall effect as stated above. Three wires - in addition to the 2 ECM connections, there is a 12V feed from fuse 1 of engine compartment fuse box. Not sure of the waveform, but I think there’s a Schmitt trigger in there somewhere to make a square peak every other crank revolution.

CKP is a two-wire, variable reluctance sensor. The reluctor ring on the crank has 58 teeth, and a gap with two missing. Expect a sinusoidal waveform (with a missing bit).

Easiest thing is to back-probe the ECM connector with a suitably shaped and sharpened paperclip. The plastic-coated ones are best - help avoid shorting stuff.

Hi and thanks to all how replied and contributed to my thread.

I've had my car fixed now and thought it might be useful for you all to know how it all went.

My freind who used to work in the car trade recommended a garage near to me who does diagnostics for the trade in our area and main dealerships. When I arrived they imediately put a set of injector test bottles on all of the injectors and imediately found that number one injector was allowing fuel to backflow into the fuel line so this needed replacing.

They put a very expensive looking Bosch diagnostic on the car and confirmed this, as well as finding six other faults which had not been cleared from previous repairs by repair shops. Probably because the diagnostic units they have aren't compatable.

I have to confess that my pulling out of the Cam sensor last Saturday also showed up because I'd not replaced the connector properly.

When I'd been checking the glow plugs in my previuos post I'd actualy been measuring the resistance of the injectors not the plugs.

In conclusion the first garage, (who are part of the Good Garage Scheme), were barking up the wrong tree and the second garage where just lying about the plugs and to be fair to them it's probably because they were not using the right test gear.

I will use the seconf garage for basic repairs in the future but all future repairs that require finicky diagnostics then I'll go to the new third gagage.

I live in the Huddersfield area and if anyone wants to know where I took the car this morning then I'd be happy to give the details. I can't praise them enough.

The cost was £240 total inc parts and diagnostic test. (The test was £40).

Thanks again to all.

So the root cause was leakback on no.1 injector. Seems odd that two successive garages didn’t perform this simple test on a non-starting common rail diesel.

I think you’re allowed to name the good diagnostic garage - their details are publicly available anyway, and you’re casting their services in a good light.

guineafowl21 said:

So the root cause was leakback on no.1 injector. Seems odd that two successive garages didn’t perform this simple test on a non-starting common rail diesel.

I think you’re allowed to name the good diagnostic garage - their details are publicly available anyway, and you’re casting their services in a good light.

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I'm surpised that a leaking injector stopped it from starting. Normal it'll just have a misfire, possibly with some smoke. I can't see it stopping it from starting completely.

Nodge68 said:

I'm surpised that a leaking injector stopped it from starting. Normal it'll just have a misfire, possibly with some smoke. I can't see it stopping it from starting completely.

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@mediaseller we’re gonna need some printouts of results...