Engine cuts out, won't restart (diesel)
 

This is one I think I've come across before, but a long while ago...

A couple of weeks ago, the engine of my 2003 Rover 75 CDT Tourer cut out as I approached a roundabout, about half a mile from home. It turned over but wouldn't restart. I have had a long-term problem with a slow battery drain which caused me to fit a battery isolation switch last year, and my first thought was that it was to do with this somehow, as I had just screwed down the contact after the car had been unused for a while. I opened the bonnet, tightened the connection, got back in and the car started fine. I couldn't think why a bad connection might have caused it to behave the way it did, as opposed to being completely dead, but I assumed some current was getting through but just not enough to start the engine.

Anyway, I've run 2-3 shortish trips since without a recurrence of the problem - until yesterday. I drove 3 miles to the MOT test centre, parked slightly in the wrong place and went to restart, same thing. Chug, chug, chug but engine not firing. Assuming it was a connection thing again I left it in the hands of the guys at the garage. But I was on the phone to them this morning and they have only been able to get it to run intermittently before cutting out again. They're testing again this afternoon, but the guy I spoke to reckoned it was a fuelling issue, something to do with what he referred to as the 'pre-pump' (by which I think he means the under bonnet pump rather than the one under the back seat). I think he said no fuel was being pumped.

Now, obviously I can't expect a decent remote diagnosis from you experts on here with so little information. But what sort of thing might this be? If it is fuelling, what should he be looking at, and what replacement parts are recommended for the various things it might be, if it turns out to be pump failure or whatever?

Could be a failing UBP, try a sharp tap on the side of it if it can't be heard running with ignition on. If in tank pump is dead then you need over a quarter tank of fuel for UBP to be able to pump fuel through. I have also seen these symptoms when internal seals in high pressure fuel pump are failing. Also check the ECM has not gotten wet, as that can also give similar symptoms.

Thanks. I have a nearly full tank, so would that likely rule out a problem with the tank pump? I have had the under bonnet pump replaced before, maybe 40-50,000 miles back, so I would hope it was not that.

I do periodically check the ECM and I never see it sitting in water - the plenum does seem to drain OK. Haven't looked for a while, though.

What brand UBP did you buy?
Any other than Pierberg or VDO and it could still be the culprit

Did you get to the bottom of this issue, I have exactly the same problem with my Dads late face lift (54 plate)
It doesn’t have an under bonnet pump, I’ve checked the plenum, there is a high tide mark on the pollen, but the ecu seemed dry.
I did check delivery from the in tank pump, but today it seems dead,
Years ago, I had an 02plate club se tourer, and I think it was a Peugeot pump that was a common replacement for the in tank pumps, is this mod advised for the later single pump system?

I can't recall, to be honest. If it does need replacing, what should I go for?

The single pump system is very reliable and failures are almost unheard of, if you have a high water mark on the pollen filter the ECM may well have gotten wet as the slosh effect of cornering can still allow water to get to it. Also the french pump is only for the twin pump early system.

Remember a diesel ECU is not sealed unlike a petrol one - worth looking for any signs of corrosion from previous water ingress - might be worth leaving in an airing cupboard for a day or two if any signs of damp.

When you turn the ignition does the oil warning light come on - if not that points to a goosed ECU - if the case PM Big Russ on here and he will sort you out- he has plenty of diesel ECU's he can programme for you.;)

Have a look on the pump for the name, Pierberg or VDO are the only ones I would fit. If you can hear it running and its noisy its a cheapo as the OEM ones are pretty quiet. MY original managed 120,000 miles.