Another diesel non start problem...

[Johnny2R]

Over the winter months my CDT had a worsening cold start problem, where it would crank but not fire up on cold mornings and required a puff of Easy Start into the air filter to get it going (which always worked). Once it had been started for the day it always ran fine. I suspected a problem with a gasket or O-ring on the HP fuel pump, from various things I'd read on here, but haven't got round to fixing it yet. As the temperatures have warmed up, it's ceased to be a problem and the car has started easily enough anyway.

Until yesterday evening, that is, when it took much longer to start than usual. It had been a cold night and I hadn't driven it for a while, so I thought maybe it was the old problem, but I was doubtful when it failed to start again without a blast of Easy Start after having driven for a couple of miles and left it for an hour or so.

This morning, it completely failed to start, even with Easy Start. Cranked OK, but wouldn't fire up. I listened to both the in-tank and under bonnet fuel pump and they're both working (or at least making a noise). So I thought I'd have a go at a quick 'n' dirty injector leakback test as mentioned here:

http://www.the75andztclub.co.uk/foru...ad.php?t=85830

None of the injectors were obviously spewing fuel, although the left most and right most (numbers?) as looked at from the front of the engine were oozing a little - I don't know how much is problematic and whether you can tell from a quick visual check like this. It didn't look markedly different from this, anyway: https://www.youtube.com/watch?v=APHi...ature=youtu.be, as mentioned here http://www.the75andztclub.co.uk/foru...d.php?t=202967. But the test confirmed in any case that fuel is being delivered to the injectors.

The ECU is bone dry, no plenum problem.

The only thing that's changed since the car was starting smoothly is that I replaced the engine cover with one I got from a car which was being broken, and the surface of the foam lining it was much dustier than on my original. I wondered at first whether a lot of dust had got in somewhere but the air filter looks OK.

So I'm wondering what to look at next? I don't think cam sensor, because this is not a hot starting issue. Still suspicious of HP pump.

[Lee T]

Just a thought as you mentioned the engine cover, check the bolt holding down the left side of the cover as I've heard of this bolt being to long and putting holes in things under it (worth a check)

[FrenchMike]

Hi,

If you're handy with multi meters,carry out these measurements ...

http://www.the75andztclub.co.uk/foru...ad.php?t=69308

good luck

Mike

[Johnny2R]

Thanks Mike. I'm not handy with multimeters, in that I've never used one. But I did in fact buy one a couple of months ago, inspired by this very post of yours! So I shall attempt to have a go.

In my multiple cranking attempts I've now drained the battery, unfortunately, so it's on charge now. But in my last attempt at cranking, I kept an eye on the tachometer needle and it didn't move at all. Am I right in thinking that this might indicate a crank sensor problem?

[Mike Noc]

Originally Posted by Johnny2R

....Until yesterday evening, that is, when it took much longer to start than usual. It had been a cold night and I hadn't driven it for a while, so I thought maybe it was the old problem, but I was doubtful when it failed to start again without a blast of Easy Start after having driven for a couple of miles and left it for an hour or so.

This morning, it completely failed to start, even with Easy Start. Cranked OK, but wouldn't fire up.

So I'm wondering what to look at next? I don't think cam sensor, because this is not a hot starting issue. Still suspicious of HP pump.

Cam sensors can fail when cold too - mine did. But if the car starts with Easystart then it isn't anything to do with the cam sensor.

Some people will tell say not to use Easystart regularly, as the engine becomes addicted to it. This of course isn't the case, but if you continue to use it to mask a fault then the problem often deteriorates over time and eventually the engine may fail to start.

This could be the case with your car. Check out French Mike's multimeter tests to establish the rail fuel pressure when cranking, as you may not have enough HP fuel pressure for the ECM to enable the injectors' firing sequence.

The HP pump only runs at 3/4 engine speed, so when cranking it is turning relatively slowly, and any pressure losses will be more noticeable.

If the car runs fine once started then could well be HP pump/injector related, but either French Mike's tests or a plug in to a T4 or similar will help pinpoint what is wrong, and save wasting time and money on replacing parts that don't need changing.

PS I see that in the time it's taken me to type this Mike provided the link.

PPS Good idea to charge the battery up fully Johnny, saves bigger problems landing on your doorstep:

http://www.the75andztclub.co.uk/foru...d.php?t=106447




.

[FrenchMike]

Originally Posted by Johnny2R

Thanks Mike. I'm not handy with multimeters, in that I've never used one. But I did in fact buy one a couple of months ago, inspired by this very post of yours! So I shall attempt to have a go.

In my multiple cranking attempts I've now drained the battery, unfortunately, so it's on charge now. But in my last attempt at cranking, I kept an eye on the tachometer needle and it didn't move at all. Am I right in thinking that this might indicate a crank sensor problem?

Possible (however rare),but i doubt as it starts with easy start (ruling out any electrical issue)

The High pressure value the most important ;
For instance ,if you get only 0.8 volt while cranking ,then ignition is impossible.
(electrical side correct)

[Johnny2R]

Originally Posted by FrenchMike

Possible (however rare),but i doubt as it starts with easy start (ruling out any electrical issue)

That was what I was thinking. But it doesn't start with Easy Start today!

LATER: Definitely not that, needle moving anyway.

[Johnny2R]

Before I attempt to do the multimeter stuff, is there anything useful an OBD scanner with Torque might tell me? Incidentally, is there any way I can do that multimeter testing solo? It looks to me like I need someone else to be cranking the engine while I'm doing the measurements.

[RogerHeinz57]

Some people will tell say not to use Easystart regularly, as the engine becomes addicted to it. This of course isn't the case, but if you continue to use it to mask a fault then the problem often deteriorates over time and eventually the engine may fail to start.

I refuse to engage in any arguments over this, but have mentioned it before, neither SI or CI engines were ever designed to run on Easy Start. Initially for testing purposes I would say that it could be useful, but in very limited dose. The reasons for not using this are endless, but here are a few to consider:
Engine damage, piston ring cleaning. This increases the distance between the rings and the piston itself, and will effectively reduce compression. Assuming the engine refuses to start, we can also bring in to play bore wash, another life shortening exercise, In the event of the engine starting after extended dose of this idea, engine runaway is possible, even more damaging. The combined diesel and easy start will impact the crankshaft wear process as the design is strong, but not designed for a flammable liquid or gas in unmeatered doses and will provide shortened longevity.
So in a nutshell these are a handful of reasons not to use it.
BTW:
Hows the maf sensor doing with a pollutant running through it?
Hows your compressions, are they any good now?

I would strongly advise proper testing of the vehicle, possibly a T-4 or diesel specialist who has a good understanding of systems, and proper diagnosis strategies to prevent further damage, assuming your car has any value because it will be ruined doing the easy start thing over time.

I am not trying to belittle or rip it out of anybody here, I am making a point that has been missed or not considered.

Hope your car can be sorted out and returned to the road a happy beast soon and cost effectively.
Cheers, John H.

[FrenchMike]

Originally Posted by Johnny2R

Before I attempt to do the multimeter stuff, is there anything useful an OBD scanner with Torque might tell me? Incidentally, is there any way I can do that multimeter testing solo? It looks to me like I need someone else to be cranking the engine while I'm doing the measurements.

No,the difficulty is to pin through the insulation and keep a good contact.
With a sufficient length of wires,you can do it yourself .

I repeat :the knowledge of the HP value is essential....and may direct you to leaky injector,HP pump modulator ...etc