Running rough P0300 P0302 P0307

mjheathcote

Centenary Club
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9,033
Started up okay, pulled out of drive okay, tick over down hill onto main road, as soon as on the main road knew something was wrong, not firing on all 8 cylinders so turned around straight back into the garage.
Engine light on with codes P0300, P0302 and P0307 on the ultragauge. Reset engine check light.
Turned off and restarted obviously not running smooth.
Engine check light not immediately come back on but pending code P0302.
I assume this must be spark plug/coil pack related?
 

mjheathcote

Centenary Club
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9,033
Certainly sounds like it. Cylinders 2 and 7 from the codes.

Just looking at which cylinder is which.
Is it correct that it starts from 1 (front) through to 4 on the UK nearside, and 5 through to 8 on the offside?
Bit odd, used to even and odd numbering down each bank on my Stag V8.
Also the rear 4 coil packs and the front 4 coil packs are different part numbers (and prices!).
The front ones are listed at over £300 each!! A complete set £2,834...
Thats ridiculous.
Need to swop around the coil packs first.
 

tulit

Member
Messages
110
Theres Bosch part numbers for both (difference is simply the length of the cable). You can order the non maserati boxed ones for much less.\

I believe the fronts are Bosch 0258007001 and rear are 0258006486.


Sent from my SM-A515W using Tapatalk
 
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Zep

Moderator
Messages
9,110
Just looking at which cylinder is which.
Is it correct that it starts from 1 (front) through to 4 on the UK nearside, and 5 through to 8 on the offside?
Bit odd, used to even and odd numbering down each bank on my Stag V8.
Also the rear 4 coil packs and the front 4 coil packs are different part numbers (and prices!).
The front ones are listed at over £300 each!! A complete set £2,834...
Thats ridiculous.
Need to swop around the coil packs first.

It’s the other way round. OSF is 1 with 2, 3 and 4 behind. Then it starts again from 5 on the nsf.

This is what you need. https://www.ebay.co.uk/itm/233543537663
 

mjheathcote

Centenary Club
Messages
9,033
It’s the other way round. OSF is 1 with 2, 3 and 4 behind. Then it starts again from 5 on the nsf.

This is what you need. https://www.ebay.co.uk/itm/233543537663

Oh I see, the cables are moulded into the coil pack so different length for the back ones.
Are those listed therefore long enough for the rear, as well as the front ones? Assume so.
Just started her up again and as well as rough can smell unbournt fuel, so looks like coil or plug.
Will swop 1 and 2 around and see if the fault code moves first.
Thanks.
 

Zep

Moderator
Messages
9,110
Oh I see, the cables are moulded into the coil pack so different length for the back ones.
Are those listed therefore long enough for the rear, as well as the front ones? Assume so.
Just started her up again and as well as rough can smell unbournt fuel, so looks like coil or plug.
Will swop 1 and 2 around and see if the fault code moves first.
Thanks.

Yes, as Tulit says, the rear ones have a slightly longer wire.

Swapping them is a good shout.
 

hashluck

Member
Messages
1,515
Only Maserati could come up with two different types of coil pack for the same engine (largely for aesthetic reasons really) and then have one type NLS! Had all sorts of fun and games sourcing mine as wanted to replace all 8 when one of mine went (pleasantly easy to diagnose via OBD tool).
 
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mjheathcote

Centenary Club
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9,033
Yes, as Tulit says, the rear ones have a slightly longer wire.

Swapping them is a good shout.
Swopped 1 and 2 around, cleared pending code P0302, started her up, still rough, pending P0302 came back.
So not indicating coil pack at fault.
Plugs out on 1 and 2 next to compare....
 

mjheathcote

Centenary Club
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9,033
Yipee!
Pending error code is now P0301, so looks like the problem as moved from 2 to 1 with moving the plug.
Although P0307 hasn't come back with just running in the garage, I suspect that might be a plug too I hope.
Plugs never been changed from factory with less than 18K miles.
Any recommendations for replacement plugs?
 

CatmanV2

Member
Messages
48,557
Very low mileage for plugs. Can't recall the model, but someone will come along soon. Certainly looks like number 2's plug is done though.

C
 

mjheathcote

Centenary Club
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9,033
I should be getting my new NGK spark plugs today, the supplier has been waiting for a delivery from NGK.
Do they need gapping, or at least checking, and what should the gap be? Thanks.