207 1.6 petrol turbo thp misfires

[matspiderpig85]

This is the fuel pressure from cold start

[matspiderpig85]

Forgot to say, when I started driving the fuel pressure wasn't going up, stayed around the same even when accelerating then EML came on, cleared the usual misfire code, started up again and the pressure was higher and increased while I was putting foot down

[matspiderpig85]

Also realised the battery is just 52a, isn't that a bit small? Checked it today as car was in economy mode when I went to start it up, on live data when I started it the volts dropped to 11.8, left it running a few minutes, turned it off and less that 10 minutes was down to 12.1/2. Just wondering if a crap battery could be causing problems with the coils at all?

[wurlycorner]

I can't see in those live data screenshots - is there a misfire counter function anywhere? Ideally separate by cylinder?

[matspiderpig85]

Not separate no, today was cylinder 3 but it does change. I pulled over when EML came on and plugged in while engine still running and fuel rail pressure was bouncing between 100-200 psi, the misfires only ever happen when I first set off driving, at the moment I'd say about 8 times out 10. This morning it was in economy mode when I went to start it , not sure the right battery is in it either, only 52ah. I've no rattling noises or anything, no coolant leaks etc. on live data it says camshaft and crankshaft are in coherence

[gwest]

I think I saw 8 bar of fuel pressure with the engine idling in one of your screenshots. It should be closer to 40. Before you start the engine the pressure from the pump in the fuel tank should be 4-5 bar. You need to plot fuel pressure against ref pressure. I think your HPFP is faulty

[matspiderpig85]

Yea it seems that when I start the car, at idle the fuel pressure is low and when I set off it doesn't increase then I get the misfires and checking the pressure when I have the codes it is the same, when I clear the codes and fuel pressure goes up it seems to be fine after a while but initial starts it can be really low and I think that's when I get the codes. I had a look where the fuel pump is, seems easy enough to change? Was only the plug I could get at properly, maybe need to take battery out and move ECU?

[matspiderpig85]

New symptom today, started the car and it stalled after a couple of seconds. Fuel pressure around 8 bar. Going to try get hold of one today and swap hpfp

[matspiderpig85]

Phoned a car yard today, they have a pump for the car. 40 quid they want so will pick that up Monday and see if it makes any difference, if it sorts everything then I'll buy a new one

[matspiderpig85]

The pump wasn't the right one, turns out no one has one in Ireland