Misfire when cold starting

Stuart Sutton

Zorg Addict
Joined
Aug 1, 2016
Points
50
Location
Bury
Model of Z
2.2 sport
Hello everyone

I've a 2002 2.2 sport . Its has this very annoying issue. When starting the engine from cold it develops lumpy idle when the engine lowers its revs down this will bring up the E.M.L . If I start it from cold and hold the throttle at around 1500 rpm until the temp gauge has started to move the light won't come on and it will idle perfectly fine on it's own then. Fault codes I have logged are P1353 and P1620. I've replaced the spark plugs with a new set of NGK and move coil pack #6 to #1 but still have misfire on #6 . Has anyone else had a similar issue? Thanks Stuart. Hopefully see some of you at Silverstone Classic.
 

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Richard29

Zorg Guru (I)
Supporter
Joined
Mar 10, 2022
Points
89
Model of Z
Z3 3.0 Auto
I have had this a few times on my e91 3.0.
Coil pack was a culprit twice which i diagnosed by reading codes and swapping coils effectively moving the misfire to another cylinder and replacing it which you have tried. unfortunatly and more expensively an injector leaking a bit of fuel in a cylinder when off was another occasion. When starring there is too much fuel in one cylinder that causes the misfire, then runs smothly once warm and burnt off. Revving the engine may clear this faster. This required more specialist help.
 

Stuart Sutton

Zorg Addict
Joined
Aug 1, 2016
Points
50
Location
Bury
Model of Z
2.2 sport
I have had this a few times on my e91 3.0.
Coil pack was a culprit twice which i diagnosed by reading codes and swapping coils effectively moving the misfire to another cylinder and replacing it which you have tried. unfortunatly and more expensively an injector leaking a bit of fuel in a cylinder when off was another occasion. When starring there is too much fuel in one cylinder that causes the misfire, then runs smothly once warm and burnt off. Revving the engine may clear this faster. This required more specialist help.
Hi Richard

Thank you for your reply. Swapping the coil packs hasn't moved the fault to another cylinder. The injector over fuelling sounds interesting . Looking at the original plugs that I've now replaced #2 #3 and #4 look to be running very lean compared to #1 ,#5 and #6 . I might swap #1 and #6 injectors and see if the misfire then moves to #1 cylinder.
 

Richard29

Zorg Guru (I)
Supporter
Joined
Mar 10, 2022
Points
89
Model of Z
Z3 3.0 Auto
Good idea, let us know how you get on. Fifferent type of injectors on N53 engine yours may not be prone to same issue. But worth a try.
 

Stuart Sutton

Zorg Addict
Joined
Aug 1, 2016
Points
50
Location
Bury
Model of Z
2.2 sport
Good idea, let us know how you get on. Fifferent type of injectors on N53 engine yours may not be prone to same issue. But worth a try.
Just read that N53 had a recall out for injectors and coil packs. I also read that they changed from Bremi to Bosch coil packs.
 

Richard29

Zorg Guru (I)
Supporter
Joined
Mar 10, 2022
Points
89
Model of Z
Z3 3.0 Auto
Yes thats right. I keep a couple of coil packs spare. Hopefully something simple on yours.
 
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