Fiat Doblo 1.3

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Fiat Doblo 1.3

Postby Dundeeguy » Mon May 20, 2013 8:04 pm

Hi guys,

Got a Doblo 1.3 multijet diesel in for running fault. It's on a 58' plate with engine number 223A9000. Complaint is lack of power below 2,000rpm. Once at 2,000 rpm, it's off like a rocket. Customer also says at time there is white smoke. Not really seen any myself. This car was in a month or so back and had lots of fault codes due to customer 'playing' around!

We had someone look at it and main code to return was fuel pressure, but everything checked out at the time. So it was suggested to us to fit a fuel filter first. We did that and fault still there. Customer took it away and told once I had been on the pico course, they could come back in :shock: Deep down we thought they would've taken it elsewhere by now!

So here I am wanting some pointers and a helping hand, please :)

Code read and codes stored were, glow plug signal (p0683), B-Can line (U1602), U1700 Can network (NCM - NBC), Can line error, wiring faulty (U1601) and also a code with no description 0246 (2, 38, c4, 26) All codes except last one cleared, but after a few more tries, final cleared and none come back yet.

Tests done are comparison compression test, looked fine. Low pressure fuel delivery to HP pump after filter was 4.5 bar and holds when revving engine. About 1 bar higher than autodata says. Have scoped fuel rail and HP pump sensor, injectors and MAF sensor and have attached for people to browse and give their opinions on the results. To me, it all seems ok, but would just like a second opinion.

I notice the smell from the exhaust is like an engine with no cat fitted, but a bit worse. It does have a dpf, but there is no O2 sensor, only an exhaust temp sensor beside the dpf. I scoped this and was getting about 1.1volts with very little change to the reading, is this normal???

Sorry for the long post, and do appreciate anyone taking the time to read it and offer their thoughts.

Many thanks,

Kevin
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Re: Fiat Doblo 1.3

Postby Dundeeguy » Mon May 20, 2013 8:07 pm

Oh, meant to add what the fuel injector correction figures were in live data.

No. 1 -0,14
N0. 2 -2.5
No. 3 -1.10
No. 4 2.70

No. 4 seems strange to be the only one not being a minus figure, but this stuff is all new to me so trying to learn as quick as possible.

Cheers
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Re: Fiat Doblo 1.3

Postby KimAndersen » Mon May 20, 2013 10:09 pm

Hi there

I would take a closer look at the Wastegate Solenoid before doing anything else if I were you. DTC P0246 means Turbocharger Wastegate Solenoid A High. You should also measure boost pressure from the turbo either with a pressure gauge or a voltage reading from the MAP sensor.

So there is some good starting points to start with. :wink:

Regards
Kim
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Re: Fiat Doblo 1.3

Postby Dundeeguy » Tue May 21, 2013 6:25 am

Hi Kim,

Thanks for replying. I have just realised by your reply that I put down the wrong code! Sorry. The code was 0426 (2, 38, c4, 26) not 0246.

I don't actually know if it is a 'P' code, as there was no 'P' to be seen, just as it is written above. If the 0426 code was a 'P' code, then that would be for exhaust temp sensor, which may back up my very little voltage movement I was getting from the sensor as the exhaust got hotter.

Are these sensors used only for DPF regeneration, or will the ecu require a good reading all the time to help with the general running of the engine?

Thanks,

Kevin
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Re: Fiat Doblo 1.3

Postby arjen » Tue May 21, 2013 1:48 pm

The number 4 injector is getting a lot of extra fuel. Have you checked the leakback of the injectors?
As far as I know the temp. sensor in the exhaust is used to see if the regeneration tempature is reached.
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Re: Fiat Doblo 1.3

Postby Dundeeguy » Tue May 21, 2013 5:32 pm

Hi

Injector leak off was done by a guy the last time it was, and was fine.

Have just gone and done a leak off test over a period of 2 minutes. There isn't much difference between each injector. Each injector gives off round about 12ml. So looking ok on that front.

Will have another head scratching evening I think....
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Re: Fiat Doblo 1.3

Postby arjen » Tue May 21, 2013 6:02 pm

Can you check the boost pressure and egr feedback from 1000 to 3000 rpm?
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Re: Fiat Doblo 1.3

Postby Dundeeguy » Wed May 22, 2013 8:35 am

Hi

I'm having a day off today, but might pop in later for a play around. We don't have a boost pressure gauge but will see what I can get electricaly from turbo and egr.

One thing I overlooked were the injector codes, so I checked them and they were fine. However, I input the codes again just in case.

Another observation we have made was, when the engine is cold, it can stall very easily. Most diesels will quite happily take off with no revs, this one doesn't. You need to add revs to compensate. Also, it appears to have a slight misfire. I wouldn't say it was fully off on a cylinder, just uneven enough to notice as you pull away.

I will report back with further information should I get any.

Thanks
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Re: Fiat Doblo 1.3

Postby KimAndersen » Wed May 22, 2013 10:42 am

Hi Kevin

A comment on the missing oxygen sensor. I think it's a bit odd there is no oxygen sensor on this car- when i know on a Fiat Grande Punto 1.3 with a 75/90 hp engine where there are a oxygen sensor mounted on this car.

Are you sure its a exhaust gas temperature sensor on your car ?


Regards
Kim
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Re: Fiat Doblo 1.3

Postby Dundeeguy » Wed May 22, 2013 11:18 am

Kim,

Maybe I just haven't seen the O2, I'll look later on. The sensor I see goes into the DPF and looks like a temp sensor. Only has 2 wires and at a guess screws in with 15mm spanner or there abouts.

Autodata seems to say there is no O2 on DPF models, and live data just shows the O2 sensor reading as "---" So assumed it was fitted.

Will let you know later.

Cheers
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