Technical HDI intermittant rough running, power loss and stalling

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Technical HDI intermittant rough running, power loss and stalling

Steve145

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Citroen Synergie 2002 HDI, same as Ulysse JTD.

About 50% of the time it runs fine. Cruising at speed presents no problems.

However, when slowing after a long run at motorway speeds, or after a period of driving in slow traffic, the engine coughs, splutters, loses power and sometimes dies.

EML is on intermittantly.

Codes relate to fuel pressure, but not always present (I'll put the reader on it later).

So far, I've changed the fuel filter, not been touched for years, but no fuel pump debries in bowl.

Cleaned MAF, also tried running with MAF disconnected, no difference.


If the car drops into 'limp'/degraded mode, it runs fine, so I strongly suspect a sensor/electronic issue.

Feels like a fuel (lack of) problem.


Nothing appears to be behaving completely consistantly, so I'm currently attemping to clean the connections on the ECU, when I can get it off that is.

Problem appears to be worse in hot weather and slow traffic.

Any ideas?
 
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Do you hear the in tank electrical pump run for several seconds when you turn key so warning lights come on?
 
Yes, pump runs when key turned.

It always starts fine from cold, sometimes doesn't want to restart after stalling.
 
Crankshaft sensor ?
It's a classic hard to start when hot item when it's starting to fail.
Doesn't always throw a code.
 
Maybe, though I thought crank sensor was a go/no go item, with no option to switch into 'degraded' mode if it failed.

Pulled the ECU off today and cleaned the connections, it was sitting in a mess of water, power steering fluid and dead leaves, we'll see if that helps when I run the van tomorrow morning. Started and idled fine once I'd reassembled everything.

I'm beginning to wonder which bit of these vans Fiat were responsible for? So far it seems very much a PSA mess...
 
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crank sensors can give poor signal when hot then work again when cooled down.

very pleased you have made progress. had the water and oil penetrated the connector?
 
Nothing had gotten past the seal that I could see, still, sometimes it helps to plug and unplug these things a few times.
 
Run to the builder's merchants today, fine going down and driving around the yard. Coming home in very hot weather heavily loaded and slogging uphill, it coughed a few times then dropped into degraded mode and ran fine.

Giving it a break for now, I'll look at the crank sensor in a couple of weeks.

Got home with a load of steel roofing sheet, so now I have a leak free garage roof, very useful vehicles these MPVs :)
 
Fault codes can be stored in the ECU, what I would recommend is taking it to a garage with a professional OBD reader then ask them to clear the codes, it will only cost a few £s at most.
 
Right, finally got to do a bit on this.

Changed crankshaft position sensor at weekend (by feel, can't see the damn thing).

Ran fine, then, after a steady run up a long hill, back to it's old tricks.

Cough, cough, splutter, bang, CEL on and dropped into "degraded" mode, after which it ran fine the rest of the way to work.

Degraded mode sounds like an old DI Transit, rather than the usual HDI smoothness, runs ok though (limited to 3k RPM and down on power).

Always same, trouble starts after a steady run under load, e.g. up a long hill in fourth.

Ideas?
 
Ok, plugged it in, codes are P0190 fuel rail pressure sensor circuit and P0230 fuel pump primary circuit.
 
A further twist to the tale...

Now that the ambient temperature is hovering around 0 Celsius, the van is running fine. No coughing, no CEL, just as it was this time last year.

So, which sensor could be affected by the ambient air temperature?

Fuel temperature sensor?

Coolant temp?

Mass air flow sensor?
 
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