Technical Engine occasionally cutting out

[pramplin]

Hi all.
I've had an occasional problem with my Fiat Doblo Diesel Multijet that is becoming more of a problem so I fear I need to get it sorted. I don't really know much about engines so would like some advice on what sort of problem I might be looking at.
This is what happens:
For seemingly no reason I will lose power and the exhaust will billow smoke. The engine will sometimes cut out entirely, but other times it will rev slightly - repeatedly going from zero to 1000rpm and then back to zero again and it's possible to get the van to drive again if I time the acceleration with the increase in revs. Then whenever I slow, the engine tries to cut out again. This can last for a few minutes after which the problem just seems to go away. Alternatively, if I'm in a position where I can just stop the engine and wait a few minutes, it usually starts again and the problem will have gone away.
Any advice would be greatly appreciated.
Many thanks in advance,
Paul.

 

[Sillystu84]

Hi all.
I've had an occasional problem with my Fiat Doblo Diesel Multijet that is becoming more of a problem so I fear I need to get it sorted. I don't really know much about engines so would like some advice on what sort of problem I might be looking at.
This is what happens:
For seemingly no reason I will lose power and the exhaust will billow smoke. The engine will sometimes cut out entirely, but other times it will rev slightly - repeatedly going from zero to 1000rpm and then back to zero again and it's possible to get the van to drive again if I time the acceleration with the increase in revs. Then whenever I slow, the engine tries to cut out again. This can last for a few minutes after which the problem just seems to go away. Alternatively, if I'm in a position where I can just stop the engine and wait a few minutes, it usually starts again and the problem will have gone away.
Any advice would be greatly appreciated.
Many thanks in advance,
Paul.

I’ve just had a petrol car in doing the same it was basically over fueling, take cap off oil and see if it smells like diesel if it does your defo over fueling. could be anything from sensor to fuel pump

 

[pramplin]

I’ve just had a petrol car in doing the same it was basically over fueling, take cap off oil and see if it smells like diesel if it does your defo over fueling. could be anything from sensor to fuel pump

I've been trying to figure things out and in doing so stumbled across a thread somewhere on this forum that mentioned a rail pressure sensor being faulty, which seemed to cause some of the problems I'm experiencing. Could that be likely, do you think?

 

[Badumtss]

Clean the MAF to be sure first. I had the same issue and after cleaning the MAF it stabilized.

 

[pramplin]

Clean the MAF to be sure first. I had the same issue and after cleaning the MAF it stabilized.

Thanks, I'll give that a go.

 

[bugsymike]

Hi all.
I've had an occasional problem with my Fiat Doblo Diesel Multijet that is becoming more of a problem so I fear I need to get it sorted. I don't really know much about engines so would like some advice on what sort of problem I might be looking at.
This is what happens:
For seemingly no reason I will lose power and the exhaust will billow smoke. The engine will sometimes cut out entirely, but other times it will rev slightly - repeatedly going from zero to 1000rpm and then back to zero again and it's possible to get the van to drive again if I time the acceleration with the increase in revs. Then whenever I slow, the engine tries to cut out again. This can last for a few minutes after which the problem just seems to go away. Alternatively, if I'm in a position where I can just stop the engine and wait a few minutes, it usually starts again and the problem will have gone away.
Any advice would be greatly appreciated.
Many thanks in advance,
Paul.

Any chance it is trying to do a REGEN of the DPF, is it white smoke?
If you can read the error codes using a good diagnostic tool it may tell you.
However if you suspect this is possible and your driving is generally low speeds and short journeys then it may be worth putting a tin of DPF cleaner just before your next tankful of fuel and then going for a drive with engine warmed up to normal on the temp gauge and try to do at least 30 miles with the engine revs showing between 2000 and 3000 rpm so it is working a bit, try not to have to stop or slow down during this and hopefully the ECU will instruct the DPF cleaning cycle to operate.
I have seen this on many modern diesels, so it may be worthy trying on yours.
As has been mentioned earlier check for diesel smell in the engine oil and if you do what I suggested, then maybe a good time to change the oil and filter afterwards.

 

[Sillystu84]

I've been trying to figure things out and in doing so stumbled across a thread somewhere on this forum that mentioned a rail pressure sensor being faulty, which seemed to cause some of the problems I'm experiencing. Could that be likely, do you think?

Yes m8 fuel rail pressure sensor can cause it as well as map sensor and maf too

 

[pramplin]

Any chance it is trying to do a REGEN of the DPF, is it white smoke?
If you can read the error codes using a good diagnostic tool it may tell you.
However if you suspect this is possible and your driving is generally low speeds and short journeys then it may be worth putting a tin of DPF cleaner just before your next tankful of fuel and then going for a drive with engine warmed up to normal on the temp gauge and try to do at least 30 miles with the engine revs showing between 2000 and 3000 rpm so it is working a bit, try not to have to stop or slow down during this and hopefully the ECU will instruct the DPF cleaning cycle to operate.
I have seen this on many modern diesels, so it may be worthy trying on yours.
As has been mentioned earlier check for diesel smell in the engine oil and if you do what I suggested, then maybe a good time to change the oil and filter afterwards.

Could be, as it is white-ish and I do mostly do short journeys. I did put a DPF cleaner through about a month back but I didn't take it for a long drive.
I'll give this a go too.
Thanks.

 

[bugsymike]

Could be, as it is white-ish and I do mostly do short journeys. I did put a DPF cleaner through about a month back but I didn't take it for a long drive.
I'll give this a go too.
Thanks.

As I understand it , the fuel tank needs to be over half full or so + the engine fully warmed up + the DPF cleaner additive+ the revs around 2000-3000rpm +the 30 miles+no stops if possible.
All that is required before the ECU will start the cleaning cycle.
Assuming that works, but you continue with your normal town driving then the same job will be needed to be repeated regularly, all this is because of environmental regulations that undermine the benefits of a small economical diesel for town use, something the salesmen do not tell new customers on purchase

 

[pramplin]

So I added a DPF cleaner and went for a drive, keeping the revs mostly in the 2000 - 3000 range. And this morning I cleaned the MAF - which was VERY gunky. So I'm hoping things will improve now.
Thanks for the advice.