Intermittent misfire

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Apr 13, 2024 | 03:19 AM

Carl F

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Junior Member

Joined: Aug 2023

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From: Wiltshire

Intermittent misfire

Hi

I have a 2008 XKR. Every no and again I get a misfire under load. Codes P0307, P0307 and P0300.
I've changed plugs and cylinder 6 & 7 coil packs. Seemed ok but then last weekend it happened again with limp mode and had obviously lost 1 or 2 cylinders. Turned off then in again and it cleared, got home and sure enough the same codes appeared.
It's 2 opposite banks so I'm ruling out cat or sensor.
My next thought would be injectors but I'm still thinking electrical.
Any thoughts?

Carl

Apr 13, 2024 | 03:44 AM

RichardS

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Joined: Mar 2015

Posts: 1,298

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From: Evesham, Worcs, UK

I'm thinking possibly a fuel delivery/pressure issue rather than individual injectors but I'm surprised there are no codes for that.

Richard

Apr 13, 2024 | 12:55 PM

sony2000

Senior Member

Joined: Jun 2023

Posts: 488

Likes: 156

From: Montreal, Canada

First to change should be the pressure regulator sensor in the fuel rail. On occasion it maybe the engine temp sensor, sending the wrong info to the computers.
XKRs run at 72.5 psi or 5.0 bar

Last edited by sony2000; Apr 13, 2024 at 01:02 PM.

Apr 14, 2024 | 03:25 AM

xalty

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Joined: Dec 2019

Posts: 3,695

Likes: 1,221

look at your misfire counter, 7 and 3 are companions.

i fought this on an xf sc that would only act up around 3k rpm. updated pcm and ton of bg 44k so far so good

Last edited by xalty; Apr 14, 2024 at 03:32 AM.