General Doblo starting problem

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General Doblo starting problem

Supermariofiori

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Hello All,
I have a problem with an 07 doblo cargo that cranks over but will not start so I have checked the earth wire to the chassis / gearbox.
I have replaced the fuel filter, I have tested the fuel pressure switch, the pressure control valve, the camshaft sensor, air mass flow sensor and the glowplug connectors.
If i turn the vehicle over and spray a little easy start into the air intake the van will start and runs but once the engine is switched off it will not start again.
I checked the glow plug connectors and found that on cylinder 3 and 4 the wires sheaving was slightly damaged and used insulating tape to repair and refitted them then went to start the engine and it started straight away but unfortunately it was just coincidental as it didnt start after that !
Once the van is started the engine runs well so i think the glow plugs must be ok. so i'm down to crankshaft sensor, Fuel delivery or injectors.
The reason i'm saying fuel delivery or injectors is because i'm wondering if once i get the engine running its drawing enough through the system to keep it running ! I am quite happy to be shot down in flames if this is not possible !
Anyone got any ideas ?
 
Yes, enough rail pressure is crucial for the allowance to inject fuel. Start Pilot increases cranking speed for 2 or 3 seconds, injecting will be allowed then, and the engine starts.
I'd look after the battery, and its connections to the van first.
I never heard of a Doblo refusing to work due to low pressure but i heard from Ducatos, Mercedes Vitos , and VW T6' having done that under high strain. Usually they could restart after having the engine let cool down for some time.

So, my question: Since the rail pump relies on the oil's shear viscosity/stability, how is your oil? A 2007 Diesel is always a Multijet. The latter tend to fill up the oil with Diesel, especially, if the regenerating process of the DPF is interrupted or not done completely after it had been started.
Since you won't be informed when the process is in progress you must find that out indirectly. When having run the engine warm, try to go at a speed of 70 to 100 km/h for at least 3 minutes. Then take the gear out and let engine drop to idle. Then watch the momentary fuel consumption. If it is above 2.0 litres/100km the system is trying to regenerate the DPF (burn the soot away). If your dash is not able to show the momentarily consumed fuel you should watch your rev meter. Usually it should be just short above 900. When the system tries to regenerate it will be just about 1,000.
Even if i notice that short before home i let the system do going at a rev speed of 1,800 t0 2,500 until the process will be done. Climbing a mountain is usually helpful since the engine needs a lot higher temperature in order to burn the soot away than just moving the van.

My advice: Change the oil and the oil filter. Have a proper battery built in. Control the wiring and its connections, clean them. Then try to start the engine.
If you succeed you know a bit more about your van. If not you sorted at least usual problems out by having fixed them.

Did you ever consider to read the system out?
 
Ok Thanks guys, I have took the van to get MOTed so the garage are going to diagnose the starting issue and then I will post the work done on here to help out others who are having similar issues.
 
Hi, did you get to the bottom of your starting problems, I have the same issue when the engine is warm.
Cheers.
 
I had until today a hot start problem, looked at everything over the past months to sort it, in the end decided it was the HP fuel pump, my thyroid was that when the engine was warm the parts in the pump expand and when cranking at starter speed the pump can’t deliver the pressure, once started at Rickover and beyond the pressure was sufficient for the engine to run.chances it in the end and forked out , twenty minute job and now engine starting at all temperatures.
 
No, figured it wasn’t the RPM sensor as Rev counter worked OK when cranking over, it was a proses of logical thinking as to what would alter when it got warm, and a £230 gamble that paid off.
 
Good morning,
The van has been at the garage since I put it in for mot. They stripped the HP pump and said it was scored inside so they got another pump and fitted it, after this they said the van was starting but was running rough.
They said it could do with a pressure regulator so I bought a new one and sent it to them. Delivered 15-10-21
I believe that on the 16th they went to start the van and it didn’t start and as they have said they have spent too much time on the van it has sat there ever since !
When I drove the van to the garage the engine was running really well, a very nippy van for a 1.3.
I am going to email the garage today to ask what’s happening !
 
Hi,

has there been an end to the story?

The reason why am asking is that my Doblo showed a similar problem recently. Just cleaning all engine related connectors of the concerning cable harnesses solved the problem.
If it would have not i'd put a reasonable amount of veg oil in the tank since veg oil decreases the fluidity of the fuel what increases the internal rail pressure if the HP pump is worn out.
I didn't need to.

Cheers for the reply in advance
 
Hi,

has there been an end to the story?

The reason why am asking is that my Doblo showed a similar problem recently. Just cleaning all engine related connectors of the concerning cable harnesses solved the problem.
If it would have not i'd put a reasonable amount of veg oil in the tank since veg oil decreases the fluidity of the fuel what increases the internal rail pressure if the HP pump is worn out.
I didn't need to.

Cheers for the reply in advance
The garage I took the van to had no luck with it and the labour trying to repair it was more than the van was worth, I did a deal with the garage and they took it off my hands and to this day it is still in their yard declared Sorn.
 
Hello All,
I have a problem with an 07 doblo cargo that cranks over but will not start so I have checked the earth wire to the chassis / gearbox.
I have replaced the fuel filter, I have tested the fuel pressure switch, the pressure control valve, the camshaft sensor, air mass flow sensor and the glowplug connectors.
If i turn the vehicle over and spray a little easy start into the air intake the van will start and runs but once the engine is switched off it will not start again.
I checked the glow plug connectors and found that on cylinder 3 and 4 the wires sheaving was slightly damaged and used insulating tape to repair and refitted them then went to start the engine and it started straight away but unfortunately it was just coincidental as it didnt start after that !
Once the van is started the engine runs well so i think the glow plugs must be ok. so i'm down to crankshaft sensor, Fuel delivery or injectors.
The reason i'm saying fuel delivery or injectors is because i'm wondering if once i get the engine running its drawing enough through the system to keep it running ! I am quite happy to be shot down in flames if this is not possible !
Anyone got any ideas ?
I had the same issue. I replaced both battery terminals, and it starts every time. Once it starts it goes like a rocket, but a nightmare to start, replace battery terminals with brass ones.
John.
 
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