Diesel limp mode and now starting issues...

Hi All,

I'm hoping for some advice to avoid rather costly investigation works and to try and root out any simple fixes for this problem. I'm new to the forum so if I've not included enough detail let me know and I'll do my best (although I am not a mechanic!!!)

The car: 2002 Citroen C3 1.4 16v SX diesel with 82,000 on the clock with a full service history.

I drive the car on regular long runs (excess of 200 miles at least once a week) travelling to work and it was doing four or five short runs (sub 15) per week. No black smoke on start up or heavy acceleration.

When I first got the car it would routinely show and EML but a garage confirmed this was due to carbon deposits etc so I flushed through a cleaner and then would only fill up with Shell.

The problem:
The car would went in to limp mode with an EML on one of the long runs but by the time I got back home, turn it off and restarted the EML had turned off. It was becoming increasingly more difficult to start in the mornings, although it would with a punch of the throttle.

With all of the news of bad diesel gelling (probably likely caused by the increased bio-fuel in this years batch thanks to the new EU legislation increasing the percentage up to a max of 7%) I suspected this might be the problem so I got some professional cleaning additive (archoil) into a full mix of diesel and went on a long run to flush it through (500 miles). No problems, no light, no limp mode ... until I got down to under half a tank when it went into limp mode with EML. The next morning the car wouldn't start at all (ticking over but not firing up) so I called out Greenflag and typically the thing started first time (although not perfectly). He left it running for a while, turned it off and on again and it started every time. He plugged in and to read the codes and came back with the following:

P1351 - Undefined
P0401 - EGR Flow Insufficient
P0002 - Fuel Volume Regulator Control Circuit
P1163 - Undefined
P0266 - Cylinder 2 Contribution / Balance
P1207 - Undefined

He also mentioned there might be a bad batch of diesel going around as five of their recovery truck had all gone into limp mode at the same time that week. The codes were cleared.

Anyway, I planned to get the car to a local Citroen specialist to have a look at also to change the fuel filter but couldn't go for a couple of days as I was away on business. When I went to take the car it would not start again, so I called out the guys again. Different chap looked it over and got it started by manually priming the fuel line. it got started but he said there was low pressure before start up but this seemed (as far as could be gauged at the side of the road without a full test) to normalise when running. He checked the fault codes and not surprisingly nothing was on there.

The car went to the garage and had the fuel filter changed and an inspection of the fuel lines and connections for any obvious faults (of which there were none). They mentioned the difficulty starting but it seemed to improve with the new filter. when I picked the car up it would not start and needed a sniff of easystart to get it going. I went out for a run to get her up to temp and put some new fuel in. On driving around it seemed fine but then went into limp mode when I got up to about 4000rpm. Now comes the tricky bit for me ... in limp mode I applied the brakes reasonably sharp so the nose dipped a few times and the car came out of limp mode revving feely and running ok. This happened a few times but cured each time with the heavy breaking to rock the car.

It would suggest to me that something is getting blocked but I don't know where to start except it is due for another service so I might get this done to change all of the other filters and fluids for good measure and I have seen on another forum to turn the ignition on (but not start the car) then off for ten seconds and repeat 2/3 times - if this makes the car start easier this points to a faulty pump maybe??

Any help or suggestions would be really helpful. Do you need more information??

Thanks,
David

Welcome to the forum DavidB,

When I first got the car it would routinely show and EML but a garage confirmed this was due to carbon deposits etc so I flushed through a cleaner and then would only fill up with Shell.

Carbon deposits where? I think there may be a more serious issue, like EGR that causes the EML. You can only diagnose EML problems with the right equipment - Lexia or possibly OBD2 if you are lucky.

P1351 - Undefined
P0401 - EGR Flow Insufficient
P0002 - Fuel Volume Regulator Control Circuit
P1163 - Undefined
P0266 - Cylinder 2 Contribution / Balance
P1207 - Undefined

all those 'Undefined' show the shortcomings of using a generic reader, you only have half the story. (see above for lexia link)

in limp mode I applied the brakes reasonably sharp so the nose dipped a few times and the car came out of limp mode revving feely and running ok. This happened a few times but cured each time with the heavy breaking to rock the car.

Like a loose connection that changes resistance as the wiring harness is moved around under heavy braking.

It would suggest to me that something is getting blocked but I don't know where to start except it is due for another service

I don't think that points to something being blocked, but getting the service that is due is a very good start.

I have seen on another forum to turn the ignition on (but not start the car) then off for ten seconds and repeat 2/3 times - if this makes the car start easier this points to a faulty pump maybe??

This procedure is to power up the pre heat glow plugs on non HDI engines to aid starting on engines that are worn out or lacking maintenance. Its not going to affect the pump. Its not going to help your C3 HDi Diesel.

Any help or suggestions would be really helpful.

Get the servicing up to date, then read the codes with lexia, record them, clear them, drive around then read the codes again.

Its the last set of error codes from lexia that are the ones to investigate.