The 75 and ZT Owners Club Forums - View Single Post - Rover 75 CDTi - Non-starting problem

Matt_75 · 27th July 2022, 19:59

Hello all,

I'm after a bit of help please as I'm struggling to diagnose a non-starting issue on my 75.

It's a 2003 CDTi Manual Classic SE with about 72,000 miles and has been off the road since 2018. I bought it as a non-starter and diagnosed the issue as a failed in-tank fuel pump. I replaced the pump and the car started, ran and drove around on several occasions. I did have one or two hesitant starts though.

Idle was lumpy so I cleaned out the EGR valve and intake manifold as both were heavily coated with soot. It seemed to idle nicely after this (may have been coincidence?) and I ran it on 3 or 4 occasions without issue.

I then replaced the radio and since then, it has refused to start. The engine turns over on the starter and occasionally coughs but no more than that. I've been following FrenchMike's instructions to try and diagnose the issue:
https://www.the75andztclub.co.uk/for...ad.php?t=69308
https://www.the75andztclub.co.uk/for...d.php?t=109615

Voltage at the low-pressure fuel sensor measured 3.82V before a fuel filter change and 3.80V after. This is slightly below the 3.9V mentioned in the 'How To' but is above the 2.6V minimum I read in another post. The under-bonnet pump is a bit noisy but flow appears to be good when I disconnected the outlet from the filter and the voltage readings seem to back this up. I listened for the in-tank pump and I can hear it running.

The cam sensor gave a 12V reading, dropping to 0V when a metal object (socket) was waved in front of it.

The high-pressure fuel sensor gave a 0.5V reading when priming the fuel system but only rose to around 0.7V when cranking the engine over, the target in the 'How To' is 1.2V. I found that if I primed the fuel system several times before attempting a start, I would briefly get a reading of 0.9V when cranking and the engine would cough and run for maybe half a second before dying and falling back to around 0.7V.

I performed a leak off test on the injectors expecting one or more of them to show an obvious problem, but this is where I'm struggling. Having never done this before, I don't know what "normal" looks like. Number 2 (going from left to right) seemed to leak the most, followed by 3 but it didn't look that bad to my untrained eye. I would guess about 2 or 3ml from about 20s of cranking. I recorded a video which is here: https://youtu.be/E2JthP0jTUs

Does anyone know if this is sufficient leak off the prevent it starting?

If it isn't, are there any suggestions as to what I should look at next? Would clogged injectors result in a low pressure (voltage) reading? I didn't think so but I'm not experienced in diesel injection systems. I'm thinking other possible candidates are: high-pressure pump, high-pressure fuel sensor or fuel pressure regulator.

I tried a squirt of Easy-Start in the EGR valve and it briefly fired up on this but died. I'm reluctant to use it again though as it sounded awful.

Thanks for your help,
Matt

27th July 2022, 19:59	#1
Matt_75 Gets stuck in 75 Saloon Join Date: Apr 2022 Location: North Somerset Posts: 547 Thanks: 13 Thanked 20 Times in 8 Posts	Rover 75 CDTi - Non-starting problem Hello all, I'm after a bit of help please as I'm struggling to diagnose a non-starting issue on my 75. It's a 2003 CDTi Manual Classic SE with about 72,000 miles and has been off the road since 2018. I bought it as a non-starter and diagnosed the issue as a failed in-tank fuel pump. I replaced the pump and the car started, ran and drove around on several occasions. I did have one or two hesitant starts though. Idle was lumpy so I cleaned out the EGR valve and intake manifold as both were heavily coated with soot. It seemed to idle nicely after this (may have been coincidence?) and I ran it on 3 or 4 occasions without issue. I then replaced the radio and since then, it has refused to start. The engine turns over on the starter and occasionally coughs but no more than that. I've been following FrenchMike's instructions to try and diagnose the issue: https://www.the75andztclub.co.uk/for...ad.php?t=69308 https://www.the75andztclub.co.uk/for...d.php?t=109615 Voltage at the low-pressure fuel sensor measured 3.82V before a fuel filter change and 3.80V after. This is slightly below the 3.9V mentioned in the 'How To' but is above the 2.6V minimum I read in another post. The under-bonnet pump is a bit noisy but flow appears to be good when I disconnected the outlet from the filter and the voltage readings seem to back this up. I listened for the in-tank pump and I can hear it running. The cam sensor gave a 12V reading, dropping to 0V when a metal object (socket) was waved in front of it. The high-pressure fuel sensor gave a 0.5V reading when priming the fuel system but only rose to around 0.7V when cranking the engine over, the target in the 'How To' is 1.2V. I found that if I primed the fuel system several times before attempting a start, I would briefly get a reading of 0.9V when cranking and the engine would cough and run for maybe half a second before dying and falling back to around 0.7V. I performed a leak off test on the injectors expecting one or more of them to show an obvious problem, but this is where I'm struggling. Having never done this before, I don't know what "normal" looks like. Number 2 (going from left to right) seemed to leak the most, followed by 3 but it didn't look that bad to my untrained eye. I would guess about 2 or 3ml from about 20s of cranking. I recorded a video which is here: https://youtu.be/E2JthP0jTUs Does anyone know if this is sufficient leak off the prevent it starting? If it isn't, are there any suggestions as to what I should look at next? Would clogged injectors result in a low pressure (voltage) reading? I didn't think so but I'm not experienced in diesel injection systems. I'm thinking other possible candidates are: high-pressure pump, high-pressure fuel sensor or fuel pressure regulator. I tried a squirt of Easy-Start in the EGR valve and it briefly fired up on this but died. I'm reluctant to use it again though as it sounded awful. Thanks for your help, Matt Last edited by Matt_75; 27th July 2022 at 20:01..