Hi All, I have done a lot of searching regarding this topic and pretty much all I can find are dead threads where OP didn't bother to come back and notify what the actual issue was. The one common theme that I was able to find is that this could possibly be a leaky injector, but I kind of doubt it... let me explain.
My car is N54 FBO + Pure Stage 2. Recently decided to go with the recommended one step colder NGK plugs gaped down to .021 so that I will be prepared to turn up the boost once the weather gets nicer. They run great, but on cold start my car will misfire in cylinder 1, 2, ,and 5 for about 30 seconds. After that, the car idles like butter. If I park for 45 mins and start the car again, it starts and runs just fine, only issue is if it sits over night. What is odd, is that my old OEM 3 prong spark plugs did not do this. They stuttered a bit on start up, but no misfire codes.
A few more details
-Injectors are index 12, only 10-15k miles on them.
-Delphi coils, also 10-15k miles.
-Compression test right before putting the new plugs in showed equal compression on all cylinders.
-Engine has 150k miles on it.
Any ideas? If it were an injector, wouldn't I expect a misfire on just one cylinder? If it were coils, wouldn't I have issues are high RPM? Only problem here is on initial cold start up.
