Car misfiring when cold

Hi - just wondering if anyone could help me?

Bought my Citroen C3 Desire from new, K reg, so getting on a bit now, but been very reliable (just one lady owner - me - 54,000 on clock).

A few weeks before Christmas went to fill up with petrol as nearly empty tank - hadn’t even got out of the petrol station when the car started misfiring (never done this before). Drove it home, next day was ok, but then on way home from work engine light came on, misfiring/juddering again.

To cut a long story short, took it to the garage we use in work and they did new spark plugs/coil unit. All was well for a week, then started again, engine light on, misfiring. Thought maybe picked up contaminated petrol, so garage put some chemical in tank, worked fine, few days later same problem.
Since then, got AA to come for Homestart and they did the diagnostic thing and it said fuel injector 4 fault, so had a new one put in, drove again 2 weeks, same problem again, only car loses power and stops in road which is quite dangerous!

Tried it again this morning as wasn’t too cold out, engine light comes on again, but after warming it up, juddering stops, engine light still on though.

Any thoughts on what else it could be?

Thanks

Satellite wrote: ↑Mon Jan 14, 2019 3:30 pm engine light comes on again, but after warming it up, juddering stops, engine light still on though.

Any thoughts on what else it could be?

Hello Satellite.

You can't really guess at these things with any success. You need to read the codes and take it from there.

You can read the codes yourself with a cheap OBD2 reader from amazon (here).

They look like this:
The 'check engine light' or MIL is telling you there are codes stored that need to be read.

As soon as you have the codes, note them down, clear them (if they will) and run the car again. Then note down the new codes and list them all here.

This is the location of a 2005 Citroen C3 diagnostics port - behind 'FUSE BOX'



This the an OBD2 reader plugged into the diagnostics port and its reading the codes (not shown in the picture).

Thanks for the help - Homestart and work mechanic have done diagnostics, showing up as fault fuel injector 4, which was recently replaced, but same still showing up last time tested?

Work mechanic coming to pick up again on Thursday for another look, but the car’s not worth that much so don’t want to keep throwing money at it, just thought someone on here might have some suggestions as to what else it might be?

Satellite wrote: ↑Tue Jan 15, 2019 11:58 am just thought someone on here might have some suggestions as to what else it might be?

If you want guesses, then there is this common C3 fault - Leaking washer jets causes damage to fuel injector on the C3.

Satellite wrote: ↑Tue Jan 15, 2019 11:58 am Homestart and work mechanic have done diagnostics, showing up as fault fuel injector 4

Unfortunately this is not how the codes work. An injector fault doesn't necessarily mean a faulty injector.

The error codes are listed by 'P' codes and each fault will have a 'P' code that is used to diagnose the fault. The code reader above will give the 'P' code, but homestart and work mechanic didn't give you these.

Hi.

So, interestingly I’ve just dealt with a faulty injector on cylinder 4. (I have the same car as you) I bought second hand just recently.

Mine was a different issue though, mine was caused by a leaking injector. Diagnosed by a fuel fouled spark plug on cylinder 4 and hard start when warm. (Which I’ve now fixed by replacing said injector) During my diagnosis; the injector on 4 that was leaking for me was not a stock oem injector and had been relaplaced in the past by the previous owner at some point. So I researched it and it seems these cars suffer problems, particularly with injector 4, what happens is the washer jets can leak liquid and drip down directly onto the injector. This was fixed by Citroen with revised jets.

Try spraying your jets, wait a little while and open the bonnet and see if you see water droplets on the underside of the jets (often on the tubing)

Your problem sounds more likely to be an injector that isn’t dispensing fuel as opposed to a leaking one. And I wonder if it’s not the injector that’s at fault, I think you might have an issue with the actual wiring that goes to that injector. But I’m just following logic and making assumptions. What confuses me is the fact that it’s an intermittent problem.

I personally would point the mechanic in this direction though.

It’s a shame you haven’t got the old spark plugs to read. They would give you an idea of what’s happening on that cylinder