Engine mgmt light help

[Brouse]

Hi folks,

Had my first EML on the dash in 3 years of owning my Z

It was on a drive home from TWG 30 miles or so, enjoying my new CSL geometry. Pressing on but not nailing it, I'm quite feather footed, 4k rpm tops.

Obviously I'll call TWG on Tuesday but in the meantime I wondered if anyone had any insight...

The car was a bit hesitant on acceleration a couple of times, then started sounding rough. The roughness almost sounded like I'd hit a limiter if that makes sense, like the fitting order was suddenly scrambled. I backed off and chilled and then the light disappeared. I pressed on briefly again after some time and it was fine. Very brief experience but concerning nonetheless!

 

[enuff_zed]

Could be several things and a code read would help, but I had a similar experience which turned out to be a loosely fitted coil. In that case I simply pushed it on properly.
It could be the first signs of a coil or plug failing?

 

[Brouse]

Should be able to get a reader on it later as my brother has one.

I did wonder on plugs, they've been in since 2020 and have 20k, (Bosch plugs and coils). As they on come up on Insp II I assumed they had some life still. But it has been pinking a bit recently. I use Shell Vpower/Momentum FYI.

 

[Brouse]

Cylinder 4 misfire P0304, hopefully just that simple. Will inspect plug and go from there...

 

[enuff_zed]

Cylinder 4 misfire P0304, hopefully just that simple. Will inspect plug and go from there...

Swap the coil to a different cylinder first and see if the fault moves with it.

 

[BumpyZ4]

That happened to me last week and it turned out to be a bad coil.

 

[Brouse]

Fault doesnt move with the coil, still number 4, spark plug looked great so combustion etc is fine

 

[enuff_zed]

Fault doesnt move with the coil, still number 4, spark plug looked great so combustion etc is fine

Did you clear the initial code?
Just asking as originally you said the fault didn't re-appear.
So you've swapped the coil and the fault has happened again, still on the same cylinder?

 

[Brouse]

Ah didn't clear original code tbf...

 

[enuff_zed]

Ah didn't clear original code tbf...

Excuse me while I just............................. :headbang:

:rofl:


Well swap the coil to a different cylinder then wait for it to happen again. When it does, see which cylinder.
But do clear the codes now.

 

[Brouse]

So cleared code, swapped plugs ran like a dream, swapped back ran great again. Only thing I did additionally was make sure the connector was seated snuggly on each coil, prob 1mm away from being fully seated in a couple of cases. Did a short run of 14 miles to check if I fluked something and all good.

Got a longer drive to do Thursday so will see if anything comes up again.

 

[enuff_zed]

So cleared code, swapped plugs ran like a dream, swapped back ran great again. Only thing I did additionally was make sure the connector was seated snuggly on each coil, prob 1mm away from being fully seated in a couple of cases. Did a short run of 14 miles to check if I fluked something and all good.

Got a longer drive to do Thursday so will see if anything comes up again.

One of those things that may never come back, but you need it to if you went to find out what it is.
I think I would have left the coils swapped as now if it happens again on cylinder four you still don't know if its coil or plug.