engine Intermittently cuts out

[Picamik]

Citroen Xsara Picasso 1.6 HDi. 2006

Folks, I have written about a couple of previous faults, but I fixed them both myself, and wrote up what I did (apparently, it has helped somebody).
Now, I have a new problem. This usually happens shortly after starting to drive - usually when the engine is cold, but sometimes after it has been standing for a short enough time for it not to have cooled down more than half way (while I went into a shop, for example - like today). It usually happens while I am accelerating, and the engine cuts out very briefly. It has been doing this for a year or more, and at first, the cutout was so brief that I thought it had simply not fired on a single piston power stroke. It would usually happen once, or occasionally two or three times, but that was all. Then one day, I had been driving for a minute or two, and the engine completely cut out and the car coasted to a stop. I switched it off, then on again, and it started and ran fine - but I was concerned it was going to conk out, and returned home.

In the last few days, it has got worse, and is cutting out for half a second at a time (which equates to 20-30 power strokes). So far, it has never let me down, but I fully expect that it will if I don't solve this. It's like a petrol car that has had power to the spark plugs switched off for a moment. There is an abrupt loss of power, and when it comes back, it is equally immediate. There is no fade out / fade in of power.

Of course, it has never done this while I have been looking at the engine, or even when the car has been stationary, so I have no idea what is causing it. The best guess I can make is that a wire connection is intermittent, perhaps somewhere close (electrically) to the EMU.

Has anybody else had a similar experience - and solved it? If not, does anybody have a viable suggestion?

Thanks, Folks.

[wheeler]

You really need to get a diagnostic check done first to hopefully give a hint as to where to start looking.

[admiral51]

Does the engine actually cut out like an engine stall or is it more a case of lack of power, a bit like foot flat to the floor and no response?
Assuming the latter then the reaction from a driver would be to lift off the throttle and then putting foot down power restored ?
Without codes we are all guessing but it is a 1.6 so from previous experience does the vehicle have the double butterfly air doser and turbo vacumm valve that caused me so much aggro on the old Devil Car.
Symptoms are very similar need to dig out the link to the old thread.

Colin

[Picamik]

To answer Colin, above, I refer to what I initially said about the fault : " It's like a petrol car that has had power to the spark plugs switched off for a moment. There is an abrupt loss of power, and when it comes back, it is equally immediate. There is no fade out / fade in of power."

I don't know what can cause that on a diesel engine. What stops the engine when it is switched off?

To answer the point about the diagnostic check, I called a garage yesterday to arrange a service, and was told that if the engine light is not on (on the dashboard), then there is no diagnostic message to read.

I said in March that I was concerned it would conk out. It did - on a city roundabout 25 miles from home. I put it into 1st gear and drove it to the side of the road using the starter motor. My first try in an electric car!! I found that Green Flag would tow me 10 miles for £150. I was lucky that another motorist (a van driver) stopped to help, and towed me to a safer place a block up the road. He had previously trained on the 1.6 diesel engine, and had a brief look. He took off the plastic cover over the injectors, and asked me to turn the engine on the starter to see what noises it was making - and it started, and I drove home.

I have booked a service, but they tell me there will be no diagnostic messages because the engine light is not on (it does come on until the engine starts), and I can just see that a service will not find any fault. If anybody has any suggestions, I'd be most grateful.

[GiveMeABreak]

It could very well be fuel starvation issue, or a faulty crank sensor, or a dodgy fusebox.

You' will have a better idea once a diagnostic has been done. Any fault codes will be logged. The engine management light may well light up during ignition on and it is normal for it to go out after the engine has started. If it stays on though or flashes it may indicate a pollution fault.

[admiral51]

Hi
Just re read your original and last post and i think you are being misled in terms of what a diagnostic session involves from your garage.
Just because there is no visible engine/service fault light showing it does not mean that there is not a fault logged and stored.
A diagnostic session will show all recorded faults and provide specific codes that will allow those that are well above my paygrade to provide you with advice on what could be the problem.

A lot latter than i would have liked have a look at The Devil Car Thread and i hope it helps and maybe explain some of the symptoms you have but you really need to get the diagnostic session done.
It will probably cost around £80-100 but if you are paying for it you are entitled to a detailed report of what the report says.

Colin

[Rp0thejester]

Just a quick one Admiral, If paying 80 to 100quid for a diagnosis from a comp box at a garage, is it worth buying your own?

[admiral51]

I did get a Lexia/Diagbox kit and install CD for around the £100 mark 3-4 years ago. Add in a second hand cheap windows 7 laptop for £30-40 it has saved me hundreds of £££ over the years but the info i have got from it would be useless without the brilliant help and support from the members within this forum.

So yes if you are going to run pre 2015( personal view ) PSA vehicles then yes get one and keep donating to this incredible forum but follow the rules that Marc has posted about the use of the Diagbox it is very very important

Colin

[Doo]

Hi, I just skimmed through this and it definitely sounds like a crank sensor fault. They tend to get contaminated. When they're cold, they can send a decent signal, but when they get hot, the resistance changes, going out of standard parameter range. The usual issue is starts cold, warms up erratic, hot engine stalls or wont restart (when you shut down, a hot engine gets hotter as the coolant is no longer flowing).

However, just to add icing to the cake, they don't always show up on a diagnostic reading! If you're lucky, some diag can test the range and flag up as comms error or out of range or improbable reading or some such grammar.

[Picamik]

Thanks, Folks, for the suggestions. I took the car for diagnostic and service today, and on the way, the fault happened 3 times. "The way" incidentally, represents about 3 miles, so the engine wasn't hot. It was probably about warmed up by the time I got there. It simply stopped firing and coasted to a halt, running against compression. Luckily, it started again on each occasion after a switch off / switch on.

Usually, if your engine conks out, your concerns are looking around at other traffic and finding a spot to pull over, so it was only today that I noticed that the instant it stops firing, the ESP light came on. I called the garage to tell them, because I thought it might be vital information, but they told me it was quite normal, because the engine had stopped. But it hadn't. It was still being driven by the car, because it was still in gear and still coasting, and the ignition was still switched on. Then they told me that it was because the battery voltage goes down really low if the generator isn't turning (which it must have been). However, this was the same garage that told me that if the engine light is not on, there is no diagnostic information to read from the EMU. When I asked what causes a diesel engine to stop when you turn the engine off, he waffled for a while, then admitted that he didn't know. I know now - the injectors are electrically, solenoid-operated, and I guess the EMU doesn't send them a signal any more. I asked to speak to a mechanic instead of the receptionist, but they said I couldn't because of their workload.
Then they said "If you're not happy about it, you can come and pick it up any time" - a bit like "Do you see this finger,
Mr Customer? Up yours!" I would have done so, but I have no confidence in getting it anywhere else. I can just see that this is going to cost a lot of money, then I'll wind up fixing it myself. I would have had a go as a first measure, but I just had an accident with an electric wood planer, and I'll have to wait for my hand to heal.

[Doo]

Thanks, Folks, for the suggestions. I took the car for diagnostic and service today, and on the way, the fault happened 3 times. "The way" incidentally, represents about 3 miles, so the engine wasn't hot. It was probably about warmed up by the time I got there. It simply stopped firing and coasted to a halt, running against compression. Luckily, it started again on each occasion after a switch off / switch on.

Usually, if your engine conks out, your concerns are looking around at other traffic and finding a spot to pull over, so it was only today that I noticed that the instant it stops firing, the ESP light came on. I called the garage to tell them, because I thought it might be vital information, but they told me it was quite normal, because the engine had stopped. But it hadn't. It was still being driven by the car, because it was still in gear and still coasting, and the ignition was still switched on. Then they told me that it was because the battery voltage goes down really low if the generator isn't turning (which it must have been). However, this was the same garage that told me that if the engine light is not on, there is no diagnostic information to read from the EMU. When I asked what causes a diesel engine to stop when you turn the engine off, he waffled for a while, then admitted that he didn't know. I know now - the injectors are electrically, solenoid-operated, and I guess the EMU doesn't send them a signal any more. I asked to speak to a mechanic instead of the receptionist, but they said I couldn't because of their workload.
Then they said "If you're not happy about it, you can come and pick it up any time" - a bit like "Do you see this finger,
Mr Customer? Up yours!" I would have done so, but I have no confidence in getting it anywhere else. I can just see that this is going to cost a lot of money, then I'll wind up fixing it myself. I would have had a go as a first measure, but I just had an accident with an electric wood planer, and I'll have to wait for my hand to heal.

When the engine stops firing, even though it is being turned by the forward motion, the ECU is no longer sending pulses to the injectors, so the ESP says "wheels are turning, but the engine isn't driving them" (a little more complicated than that but you get the gist).

You really need a DiagBox for a correct reading. As I can proclaim, PSA cars are strange beasts that speak in tongues only the French can understand I just rebuilt my engine and it told me there was basically no gearbox! But I knew it was there because I attached it Anyway, the reason there was no comms to the box ?? I hadn't plugged in the headlamps! They were still in the boot. So I had to plug them and the fog lamp bulbs in JUST so the BSI could do a circuit test before looking for the gearbox. Once I did that, the gearbox "appeared" in the circuit. I kid you not (I actually posted on here about it).

See if any of the FCF members are nearby with a Lexia/DiagBox who would do you a massive and plug in to do a systems test. You need a live data reading to be able to find what the electronics do right at the moment of stoppage.

[Picamik]

Doo, thanks for the explanation - which makes complete sense. I had to go to the garage today to get my driving glasses from my car, and while there, I picked up the diagnostic results, which I will copy here entirely with the garage's comments <in angle brackets> and my comments [in square brackets]

Fault code p1351 pre-heating circuit permanent fault <wiring checks need to be carried out to the glow plug relay before replacing any parts>
[I have often wondered if my car has glow plugs. I know that diesel engines usually do, but they take a little while to warm up, and even when the engine has been VERY cold - standing out on icy nights - it has always started instantly. In any case, I don't think it likely that a glow-plug fault can be responsible for a misfire lasting an estimated 3 milliseconds, or for the car cutting out and coasting to a stop on a warm Sumer's day - as it is now]

Fault code p0335 engine speed signal incorrect or missing <intermittent fault crankshaft sensor needs replacing>
[In researching my problem online, I have come across mention of the crank position sensor a few times, and it makes sense to me that it could be this. If the EMU doesn't know where the crankshaft is, it won't fire the cylinders. I have told them to go ahead and change it. If this doesn't fix it, I may accept defeat and scrap the car - though I may also check the connector from the EMU - re-seat it in case of bad connections - and the connections in the wiring harness along the cylinder head to the injectors. This is because when it had died completely, and that area of the engine was disturbed by the plastic cover being removed as detailed in a previous comment, above, it started again and I drove 25 miles back home.]

ESP fault code j1208 communication with engine ecu incorrect value received <this message is received because engine has cut out>
[That's prety much what Doo explained above.]

[moizeau]

Crank sensor, as already mentioned and backed up by the diag. Also clean the plug with electrical cleaner. Ignore the glow plug fault. It's an HDI from PSA, most of us have that one. Do one thing at a time, i.e. the crank sensor without touching anything else, otherwise you won't be sure what fixed the problem.

[Doo]

Crank sensor, as already mentioned and backed up by the diag. Also clean the plug with electrical cleaner. Ignore the glow plug fault. It's an HDI from PSA, most of us have that one. Do one thing at a time, i.e. the crank sensor without touching anything else, otherwise you won't be sure what fixed the problem.

I second the glow plugs fault. I call it the ghost in the machine... These cars don't always require the glow plugs so they don't always "show up" on the scan. This is a total non fault "fault" as it were.

Every time I conduct a scan, the fault of the glow plugs shows up, yet this engine has never failed to start despite the winter throwing minus clogs at the engine and frost making my tash droop

[KennyW]

Crankshaft sensor or wiring. Checking the wiring for any nicks, splits etc this will also cause problems
Kenny