Diesel, Starting/idling issues

Hi All

I'm a previous subscriber from the UK, and have returned to the fold after a long absence.

Let me give you as much info as possible to my issue.  A friend bought a Van, its a 2005 Renault Master, 2.5 Ltr, 120DCi, it was an ex Ambulance.  It was sold as a runner but when my friend and I went to view it the seller (Garage) said that they tried to pull it out of the yard and it wouldn't idle, we tried a few times and it would fire but as soon as you let go of the key it would stall instantly, if we gave it some revs (1,500 - 2,000) it would run but would stall once we took out foot off the pedal, after a few attempts It idled absolutely fine, a solid, even revs, no fluctuations, no noises.

I said it seemed fuel/pressure related, and we did find a new fuel filter in the back. The garage said they would get it looked at........ after a few weeks they still hadn't got round to it so they agreed to knock a good chunk of money off the van and would deliver it for free so my friend took a risk a bought it, it was a really low price compared to other similar spec/age vans.

Once delivered, I plugged my Diag machine in (Snap-on Verus Pro) We saw Injector Circuit codes for cylinders 1, 3 & 4 (Codes: 18E2, 1830, 1831). We changed the fuel filter, which was really black and clearly hadn't been changed in a long time, cleared the codes,  we primed the system using the priming bulb and fired it up. ran great, we ran around in it doing a few chores and all was good.

The next morning it was back to not starting/idling, it would die as soon as you felt go of the key, we primed the system again and still the same. however, it i constantly pumped the priming bulb then it would idle fine until I stopped pumping.  We decided to change the priming bulb after some research said this was a possible cause, it ran fine after priming using the new bulb....... for a few minutes, then it would die as it someone flicked a kill switch. each time we checked the DTC's it would be Injector circuit codes again, sometimes 2 cylinders/injectors, sometime 3 and occasionally all 4.

We carried out a good visual inspection of the injector wiring as were told the wiring under the Airbox sometimes would chafe the cause issues.  All looked good!! I cracked each of the fuel lines at the Fuel Rail to ensure fuel delivery, then cracked the the lines at each of the injectors in turn and all were getting diesel.  We got it started again and it ran for a good 20-30 mins while we pottered around cleaning the inside of the cab and back then went for a much deserved pint.  an hour later returned to try and start it again and it wouldn't start/idle.

Live Data showed that the rail pressure was fluctuating quite a bit so decided to change the Fuel pressure regulator.... not the easiest job when they used Torx Bolts that are rusted, but we got there in the end and it seemed to run and idle fine, fuel pressures were a lot more stable at around 280-320 bar which is the expected pressure according to AutoData.

But after a few successful attempts start it and let it idle up to temp, then leaving for several hours or overnight and trying again, we even took it for another spin around the area, but the issue returned, still showing injector Circuit Codes, next we swapped out the fuel pressure sensor, this was because we followed the Testing procedures from HaynesPro:

1. Measure the voltage on pin 3. Is it between 4.8 and 5.2 V? - We got 4.9v
2. Measure the voltage on pin 1. Is it between 0 and 0.2 V? - We got 0v
3. Measure the voltage on pin 2. Is it between 4.5 and 5.2 V? - We got .4v, however if I unplugged the sensor and took a measurement, I got 5v so thought it was a faulty sensor.  As I got 5v I am assuming that the wiring integrity is fine, however under load we are getting voltage drop. (the only thing I'm not sure of is if this voltage will only show if there is pressure in the rail.

I'll admit it was a secondhand one from a 'working' van that was scrapped, I checked resistance between the pins and it was the same as the one already in the van so suspect that it’s not the sensor. At this point we experienced a flat battery when trying to bleed the air out of the fuel lines so are going back at it tomorrow but I'm not holding my breath as the 'New' sensor is giving the same voltage readings.

Would everyone agree that the next step would be to remove the injectors and get them tested?
Is there anything I can view/record using the diag machine to catch the live data at the point that it dies/stalls?
Would it be worth putting an amp clamp on the injectors to view the waveform?

I'm getting frustrated with it now and need a direction to head in, I would rather not remove injectors as they can be a nightmare to get out and if they break its a head off job which I would rather avoid.

Let me know your thoughts.

Thanks

Derek

So just as a quick update, I removed the injectors which had clearly been removed by the previous owner as they came out really easy which is unusual.

All injectors tested within tolerance and should not cause any issues.

I'm now thinking either wiring from injector to the ECU or the ECU itself.

Hey Derek,
I really only popped in here to let you know that you aren't being ignored. I really don't have any practical experience with diesel engines, especially European diesel engines. It seems the injector circuit codes continue to return. I don't have access to service information for that vehicle, but have you looked into the code set criteria for the injector circuit codes?
How about fuel quality? It sounds like it was sitting for some time, maybe water in the fuel?
I wish I could be of more assistance to you, I really don't like to open my mouth without anything helpful to add, but I also didn't want to see you hanging.

Thanks for the reply Noah, I did start to wonder, however I am aware that I'm UK based and most on here will be US which is predominantly Petrol rather than diesel.

I don't suppose you have a good source for code set criteria information?

Not without access to service information for that make.
I honestly wouldn't have known it was a van if you hadn't mentioned it in your post. I use shop key currently and there's no Renault information as we don't have them here. Sorry to disappoint

Been a while but I subscribed again in the hope the extra info I have and the PIDs that I have captured might shed dome light.

We got the Injectors tested and all good, we load tested all of the injector wiring and it was all good, hence we took the injectors for testing.  we still had the issue so sent the ECU off for testing/repair.

The ECU repair company bench tested it but said that they could find any fault, however someone had been inside before and not done a very good job.  We asked them to refurb the ECU, which included replacement of the injector drivers, and they said they would tidy up the previous 'poor' work.

We got the ECU back and fitted it, starts EVERYTIME, no random stalls followed by No start like we had before..... all good so far, as it did not have a current MOT test we couldn't test drive it.

We booked the MOT test (a yearly UK test to confirm road worthyness), pulled away to drive to the test centre, only to change into second and at 2400 rpm, it stalled!!!  started up again no issue, pulled away in first, changed to second, 2400 rpm and it stalled again!!

See the Image of the PIDs below and I have attached the saved file if anyone wants to download and view it in shop stream, I have added a screen grab of the same data in a couple of different views.

We no longer get Injector codes, always fuel pressure codes, I don'e seem to be able to view freeze frame data from when the code triggered on my Verus Pro.

Anyone got any clues of which direction to go next....... or is it some petrol and a match?   


 

 

 

 

Welcome back!
That's super frustrating, it seemed like you had it fixed there. Since it was all good after reinstalling the engine computer, I might investigate a pin fitment issue at the PCM connectors and maybe use a contact promotion agent like stabilant.
I'm just going to put this out there, not that it applies directly to you, but there's this industry wide misconception about dielectric grease. It is an insulator and will cause more harm than good applied to connector pins.
It's hard to see your captures, it appears as though RPM is dropping off to 0. This must be when the engine is stalling?

Good to be back, would be even better if it was under different circumstances 

Yes, the engine stalls and RPM drops to Zero, turn the key and it starts right up again. The engine is solid!, idle constant with not a single fluctuation at all.

Its really frustrating!! The PID's are a lot easier to read if you open them in Snap-on's Shop Stream application.

If feels like fuel starvation, we have since removes the tank and flushed it out with brake cleaner, pumped cleaner through the pickup line, the priming bulb and all the way to the high pressure pump too.

The strange thing is that the van drove great before sending the ecu away, with the exception of the random stalls and no starts , this makes me believe its not the high pressure pump.

Could there be air in the system that's just sitting there at idle and only causing an issue when there is a high demand for fuel and getting pulled into the injectors causing the stall, I don't think so as that would probably give Injector Codes rather than Pressure codes. its potentially causing pressure issues in the common fuel rail.

Whats the best way to test the pressure sensor?

We do have a battery light that's on permanently, but we are getting a good charge voltage from the alternator.

would a pin fitment issue be that consistent or would it be more random?

I am not sure what made you comment regarding dielectric grease, bizarrely we did put a little dielectric grease on the ECU connections..... I guess I need to get the contact cleaner out LOL 

Pin fitment came to mind because you said it was good after installing the ECU for a while. I was thinking maybe the act of disconnecting and reconnecting the computer may have temporarily masked the issue. I used to run into that a lot with Chrysler PT Cruisers.
Then that got me thinking I have seen intermittent contact issues when people go overboard with dielectric grease. I have fixed more than one electrical issue by removing dielectric grease from connectors, so I figured it was worth mentioning.
As far as testing the fuel rail pressure sensor, like I said, I don't have access to information for that brand. If you have a voltage pid, I would watch the voltage with the sensor unplugged, jump the signal wire to 5v and make sure the pod reads 5v. Then jump to ground and make sure voltage reads 0v. That's straight out of the SD book to verify circuit integrity.