Does idle chache at all if you introduce a vacuum leak at the manifold, I know you said you smoke tested it, but try and taking the MAP sensor out to see if idle changes at all.

 

I did and the map is working like it supposed to. I even installed a new map

 

I also changed the Evap purge solenoid and it still
does it. Anyone else got an idea what could it be ?

 

I?m all but grasping at straws here, however:

1) what are your fuel trims at idle? Is the STFT and LTFT generally within +/- 10%? If greater than +10, you could have a vacuum leak, if you have less than -10% you could potentially have a leaky fuel injector. If you have a leaky fuel injector, it could cause fuel to drip while the car is sitting, which could cause the engine to run rough the first few seconds before clearing itself out. Do you smell any raw fuel/rich mixtures at startup?

2) if your fuel trims are abnormally high (something like +20-30% on both the STFT and LTFT), your upstream O2 sensor could be bad and giving false data, which could fool the PCM into thinking there is a vacuum leak.

3) how old are your O2 sensors? Are you able to see their signals/readings on your scan tool? Is the upstream sensor switching back and forth between rich/lean signals, or is it flatlined and not giving much of anything? If you can overlay the two of them, take a picture of them and post it here.

 

Was 80F at ambient?
BTW, I still have the original assembly line installed CAI intake & still starts up with a smooth idle!

 

short term fuel at idle is between 0-3 fluctuating
long term shows 2- both average around 1.03
i don?t smell any fuel at startup
the o2 sensors are new i installed them 2 weeks ago and yes I can see their signals

air fuel ratio is 14.7

 

so today I changed my spark plugs and coils and right off it?s start to misfire cylinder 5. I unplugged the coil while it?s running and it didn?t make a difference . I checked I am getting 12.45V and ground and signal are good. I did a spark test and the the spark was sparking. So is it my injector wasn?t working properly and now that I changed the sparks and coils lt failed ?

 

#5 VALVES STICKING:>Service Bulletin

 

the engine is rebuilt and cleaned . I also did a valve job and all that at the machine shop. I highly think it?s a valve since it?s been cleaned and new valves and all. I highly think it?s the injector, because remember maybe the injector was weak so it start run rough a little then smooth is a sign for a weak injector then when I changed the sparks and coils now it?s getting better spark and the injector not keeping up and maybe died cus it was already going out?
Ill change the injectors tomorrow and update

 

So the misfire was a bad Injector. I replaced all of them and no more misfire but still tho when I turn the car on it runs rough for few seconds and then smoothes out doesn?t matter if it?s hot or cold like my initial post. All the stuff I changed and swapped and still does it. What else could it be?