My Citroen runs on 3 cylinders when 80 degrees hot.

[citroenpicassoowner]

Hi, I have a Citroen C4 Grand Picasso 2011 1.6 88kW petrol 4cyl.

It starts and runs great but when looking on my phone using OBD2, when it reaches 80 ± 2 degrees celsius. The first cylinder (on the gearbox side) stops working. Starts working only when I turn off the engine and let it cool down and then runs great again until the same thing happens again.

I've been googling this problem a lot but nobody seems to have this exact problem.

The car also has a fault code P1337 ( camshaft Pos. Sensor, Bank1 Short to Ground). Maybe it's interfering the cylinder wiring or something?

I tried getting rid of it by replacing the camshaft sensors, but that didn't help the main problem and didn't take the code away.

Also changed the spark plug and the ignition coil of the faulty cylinder.

I've tested the spark of the faulty cylinder when it was hot, and it had spark.

Tried testing if the cylinder got fuel by taking the spark plug out and put it back in but didn't screw in in but was loosely in there. Tried starting it to get a explosion coming out.

When i turned the key, it exploded (ignited) like once or twice only when starting, but stopped then and didnt anymore. So the problem there is that it doesnt get fuel.

I guess the problem is the injectors, right? Do i have to replace it now or may there be a easier or different solution?

Thanks.

[mickthemaverick]

Yes I'd agree you have a partially gummed up injector which seals itself when it expands with heat. Firstly I'd try removing the injector and cleaning it thoroughly and then replace it. If that fails then you may be looking at a new injector which will require programming when you put it in. Other members with more knowledge on that procedure should be able to advise you further. Good luck

[MattBLancs]

I'm not sure about the loose spark plug test technique!

Worth considering without plug in place there will be less of a draw into the cylinder from the inlet manifold (so less to draw any fuel in) as it's easier to fill it through the spark plug hole instead.

I'm sure I have read of high engine temperature related ignition faults (the one which stick in my memory is a distributor cap that had a crack which opened up as the engine bay got hot, ran perfectly when cold, badly when hot)

So I would not rule out ignition system faults as yet. Can you swap in a known good coil pack and rule that out?

[mickthemaverick]

Also changed the spark plug and the ignition coil of the faulty cylinder.

That's already been checked Matt!! You've been using your propane torch too much!!

[MattBLancs]

Ah fair enough, read about new plugs but missed that about coil pack being swapped!