Help needed, engine has a misfire
Discussion
Afternoon all
Have a problem with the engine misfiring under hard acceleration, it feels like one cyl stops firing
For a month or so my heater hose had rubbed on cyl 6 coil pack screw head and had very slowly leaked coolant water down over that coil pack and down onto the HT lead, so I thought it may have been the lead so changed them all, then changed that coil pack, misfire still there, changed all coil packs and still have the problem, my next theory is change cyl 6 plug as it probably has had cooling water dribbling over it for a month, just waiting for the engine to cool down a bit before I swap it out for an old plug.
Has anyone got any other suggestions ?
Have a problem with the engine misfiring under hard acceleration, it feels like one cyl stops firing
For a month or so my heater hose had rubbed on cyl 6 coil pack screw head and had very slowly leaked coolant water down over that coil pack and down onto the HT lead, so I thought it may have been the lead so changed them all, then changed that coil pack, misfire still there, changed all coil packs and still have the problem, my next theory is change cyl 6 plug as it probably has had cooling water dribbling over it for a month, just waiting for the engine to cool down a bit before I swap it out for an old plug.
Has anyone got any other suggestions ?
snowwolf said:
Afternoon all
Have a problem with the engine misfiring under hard acceleration, it feels like one cyl stops firing
For a month or so my heater hose had rubbed on cyl 6 coil pack screw head and had very slowly leaked coolant water down over that coil pack and down onto the HT lead, so I thought it may have been the lead so changed them all, then changed that coil pack, misfire still there, changed all coil packs and still have the problem, my next theory is change cyl 6 plug as it probably has had cooling water dribbling over it for a month, just waiting for the engine to cool down a bit before I swap it out for an old plug.
Has anyone got any other suggestions ?
I do not no but will water get into the engine over the plug Have a problem with the engine misfiring under hard acceleration, it feels like one cyl stops firing
For a month or so my heater hose had rubbed on cyl 6 coil pack screw head and had very slowly leaked coolant water down over that coil pack and down onto the HT lead, so I thought it may have been the lead so changed them all, then changed that coil pack, misfire still there, changed all coil packs and still have the problem, my next theory is change cyl 6 plug as it probably has had cooling water dribbling over it for a month, just waiting for the engine to cool down a bit before I swap it out for an old plug.
Has anyone got any other suggestions ?
goldvxr8 said:
I do not no but will water get into the engine over the plug
No Goldy, the water cant get in the engine but I was thinking it may have badly corroded the outside of the plug, I doubt it has but will take that plug out as soon as engine has cooled down a bit and find out.goldvxr8 said:
snowwolf said:
Afternoon all
Have a problem with the engine misfiring under hard acceleration, it feels like one cyl stops firing
For a month or so my heater hose had rubbed on cyl 6 coil pack screw head and had very slowly leaked coolant water down over that coil pack and down onto the HT lead, so I thought it may have been the lead so changed them all, then changed that coil pack, misfire still there, changed all coil packs and still have the problem, my next theory is change cyl 6 plug as it probably has had cooling water dribbling over it for a month, just waiting for the engine to cool down a bit before I swap it out for an old plug.
Has anyone got any other suggestions ?
I do not no but will water get into the engine over the plug Have a problem with the engine misfiring under hard acceleration, it feels like one cyl stops firing
For a month or so my heater hose had rubbed on cyl 6 coil pack screw head and had very slowly leaked coolant water down over that coil pack and down onto the HT lead, so I thought it may have been the lead so changed them all, then changed that coil pack, misfire still there, changed all coil packs and still have the problem, my next theory is change cyl 6 plug as it probably has had cooling water dribbling over it for a month, just waiting for the engine to cool down a bit before I swap it out for an old plug.
Has anyone got any other suggestions ?
My guess is that the plug could be fouled, as I would think it could have been sparking intermittently, if the water shorted the spark. Alternatively, residue from the water could have built up on the ceramic, meaning the spark can track down the outside of the plug, rather than through the core.
Didn't 007 have a misfire under load, a couple of year ago. What was the cause of that?
ARAF said:
No, the plugs are gas tight, so water won't get into the cylinder.
My guess is that the plug could be fouled, as I would think it could have been sparking intermittently, if the water shorted the spark. Alternatively, residue from the water could have built up on the ceramic, meaning the spark can track down the outside of the plug, rather than through the core.
Didn't 007 have a misfire under load, a couple of year ago. What was the cause of that?
I am hoping it is what you mentioned Araf, I am just going out to the car and taking that plug out, brbMy guess is that the plug could be fouled, as I would think it could have been sparking intermittently, if the water shorted the spark. Alternatively, residue from the water could have built up on the ceramic, meaning the spark can track down the outside of the plug, rather than through the core.
Didn't 007 have a misfire under load, a couple of year ago. What was the cause of that?
Swapped plug and tested still same problem, just to mention, it does not need to be wide open throttle to get the misfire, also in last couple of weeks I had the cats removed but decided to put them back as the car was to loud for me, I also changed the headers for a second hand set (originals) so the sensors have been removed and put back in the new set of headers, could it be the sensors? I'm not getting and engine system warnings.
This is the plug I took out
This is the plug I took out
I was hoping it was going to be the cureringram said:
Does it trigger the MIL light?
If so it should tell you what cylinder is being naughty..
I did get engine management come up on two occasions both when idling in traffic while running with no cats, then again I hadn't fitted the spacers to the after cat sensors so just assumed it was that, not had and other warnings since putting cats back.If so it should tell you what cylinder is being naughty..
ARAF said:
Plug looks okay. Have you taken out another, to compare it? What's the state of the ceramic on the outside of the plug. Is that dirty?
I think a sensor would throw the CEL, so not sure it would be that. How's the low tension wiring, that has been soaked?
Plug was very clean on the outside, the water leak was very slight, about half a litre over about a month, low tension wires all ok and not been attacked by the waterI think a sensor would throw the CEL, so not sure it would be that. How's the low tension wiring, that has been soaked?
snowwolf said:
I was just assuming the problem was coming from that cyl because of the water seepage problem but it could be any of the others?
As Richard has said, the ecu should tell you which cylinder it suspects of having a misfire.The coils have built in misfire detection for this purpose.
Water is unlikely to cause a coil a problem, they're very well sealed up.
Surely any cat/lambda related errors or problems would have been disabled when the ecu was tuned ?
ARAF said:
You say that it's under hard acceleration, but not necessarily at WOT. Does it also do it at WOT? If not, could it be the potentiometer on the throttle pedal?
I think I have had it at WOT as well as half and it carries on missing, its not a bad misfire more like a burble with a slight hesitation thrown in, its hard to notice but definitely there.stevieturbo said:
As Richard has said, the ecu should tell you which cylinder it suspects of having a misfire.
The coils have built in misfire detection for this purpose.
Water is unlikely to cause a coil a problem, they're very well sealed up.
Surely any cat/lambda related errors or problems would have been disabled when the ecu was tuned ?
How do I find out from the ECU what one could be playing up?The coils have built in misfire detection for this purpose.
Water is unlikely to cause a coil a problem, they're very well sealed up.
Surely any cat/lambda related errors or problems would have been disabled when the ecu was tuned ?
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