Xsara Picasso won't start

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Vuk1987
Posts: 36
Joined: 27 Oct 2018, 14:32

Xsara Picasso won't start

Post by Vuk1987 »

Greetings guys,

I have a problem with Xsara Picasso 1.6 16v (NFU/ TU5JP4 engine).
Engine cranks, but wont start most of the time. I have been struggling for almost a month now. First, the fuel pump was dead (got that from not hearing it when I switch on the ignition). Replaced it with a used one, and now the engine barely starts. I also have LPG installed which complicates things. Now, most of the time, when engine is cold, it will start after a lot of cranking. When it starts it works crappy. When it's hot, it won't start no matter what I did, except if I unplug the coolant temperature sensor. When the engine is off, and I unplug the coolant temperature sensor, it starts fine, mostly. The sensor is not a problem, since I firstly replaced one a year ago, and again yesterday thinking he's the problem. However, nothing changed. I read the fault codes with Lexia and I will post them here. There are codes caused by me driving with a coolant temperature sensor unpluged, but the ones that I I have my eye on are codes P0202, P0204, P0203 and P0201. I also have a picture of the diagram from the Sedre. If I've read right, wire from the injectors (parts 1331 to 1334) goes to PSF1 point 16. Is it a fuse, a relay, something else I have no idea, not an electrician. Any suggestions? Check replace a fuse/relay? Bridge something together (make a bypass)?
I have already been to a mechanic, he has no clue. I turned off the LPG by pulling out the fuse. Thanks in advance guys
Attachments
17058588980026530885966118562965.jpg
IMG_20240121_173836.jpg
IMG_20240121_173851.jpg
IMG_20240121_173903.jpg
IMG_20240121_173915.jpg
IMG_20240121_173926.jpg
IMG_20240121_173950.jpg
IMG_20240121_174004.jpg
wheeler
Posts: 6785
Joined: 21 Sep 2002, 19:07
x 701

Re: Xsara Picasso won't start

Post by wheeler »

First thing you need to do is see if there is a power supply at pin 16 of the 16 way black connector at the under bonnet fusebox when its cranking over but not starting.

Once the engine starts does it run normally without any misfiring?

I notice the coolant temp is showing as -40 on some of the screens, is this when it its unplugged?
Vuk1987
Posts: 36
Joined: 27 Oct 2018, 14:32

Re: Xsara Picasso won't start

Post by Vuk1987 »

It doesn't run quite normally, it misfires after start and chokes from time to time. Also depends on whether I'm running it with or without temp sensor plugged. I will check that thank you. If there is no power supply, what then?
Vuk1987
Posts: 36
Joined: 27 Oct 2018, 14:32

Re: Xsara Picasso won't start

Post by Vuk1987 »

"I notice the coolant temp is showing as -40 on some of the screens, is this when it its unplugged?"

Don't know, I ran lexia on engine off
wheeler
Posts: 6785
Joined: 21 Sep 2002, 19:07
x 701

Re: Xsara Picasso won't start

Post by wheeler »

-40 is the default value the ecu sees when the sensor is open circuit.
Have you ruled out an ignition coil pack fault? Very common on this engine.
Vuk1987
Posts: 36
Joined: 27 Oct 2018, 14:32

Re: Xsara Picasso won't start

Post by Vuk1987 »

wheeler wrote: 22 Jan 2024, 08:55 Have you ruled out an ignition coil pack fault?
Replaced it few years ago, but It's possible of course. Is there a way to check it without replacing it again?
User avatar
xantia_v6
Forum Admin Team
Posts: 9013
Joined: 09 Nov 2005, 23:03
x 818

Re: Xsara Picasso won't start

Post by xantia_v6 »

I would suspect low fuel pressure, perhaps a failing pump or blocked fuel filter.
Vuk1987
Posts: 36
Joined: 27 Oct 2018, 14:32

Re: Xsara Picasso won't start

Post by Vuk1987 »

xantia_v6 wrote: 22 Jan 2024, 09:05 I would suspect low fuel pressure, perhaps a failing pump or blocked fuel filter.
Interesting thing is that I replaced it previously to this problem, a few weeks ago (the pump), but the machanic put in the used one, not new. Is there a way to check the pressure? What should be the pressure (the value)?
Vuk1987
Posts: 36
Joined: 27 Oct 2018, 14:32

Re: Xsara Picasso won't start

Post by Vuk1987 »

I also replaced the fuel filter righta away, since I suspected on it first, although I change it regularly.
wheeler
Posts: 6785
Joined: 21 Sep 2002, 19:07
x 701

Re: Xsara Picasso won't start

Post by wheeler »

Vuk1987 wrote: 22 Jan 2024, 08:57
wheeler wrote: 22 Jan 2024, 08:55 Have you ruled out an ignition coil pack fault?
Replaced it few years ago, but It's possible of course. Is there a way to check it without replacing it again?
I use these > https://www.ebay.co.uk/itm/111584294839 ... BMhL7nn6Zj

There is normally enough slack on the harness to allow them to be fitter in between the spark plugs & coil pack.
Vuk1987
Posts: 36
Joined: 27 Oct 2018, 14:32

Re: Xsara Picasso won't start

Post by Vuk1987 »

Ok 12v on a 16-th pin on a 16 way black connector on under bonnet fusebox. Now I managed somehow to start the engine, but after a few minutes on running idle, the fan turned on, and warning about engine temperature and then it went off again and showed normal temperature. I guess the temp sensor is loosing contact. Any ideas now? I'm afraid it's multiple things
User avatar
CitroJim
A very naughty boy
Posts: 49242
Joined: 30 Apr 2005, 23:33
x 6091

Re: Xsara Picasso won't start

Post by CitroJim »

I'd be replacing the temperature sensor before doing much else if it's still showing= -40 on the Lexia. That'll really muck up the engine ECU mixture regulation and make it run rather rich and could be causing all the symptoms you see...
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
Vuk1987
Posts: 36
Joined: 27 Oct 2018, 14:32

Re: Xsara Picasso won't start

Post by Vuk1987 »

I replaced temperature sensor 2 days ago, and a year before that. That's the reason I'm excluding it as a cause. I put a Vernet Calorstat brand. The reason it's showing -40 in some errors is probably because I drove it with the sensor unplugged. Now I suspect that it is either sensor harness, or something worse. I will also check fuel pressure.
wheeler
Posts: 6785
Joined: 21 Sep 2002, 19:07
x 701

Re: Xsara Picasso won't start

Post by wheeler »

Have you unplugged the ecu connectors to check for water or coolant in the pins?
Its not unknown for the temp sensors to crack & allow coolant to travel up the wiring & into the ecu.
Vuk1987
Posts: 36
Joined: 27 Oct 2018, 14:32

Re: Xsara Picasso won't start

Post by Vuk1987 »

wheeler wrote: 22 Jan 2024, 20:14 Have you unplugged the ecu connectors to check for water or coolant in the pins?
Its not unknown for the temp sensors to crack & allow coolant to travel up the wiring & into the ecu.
I will definitely try that