Recently only on stone cold starts does this happen... either first thing in the AM or when Im leaving work at night. In the video you can see it clears up within minute or 2... Tell me what you think.It almost seems like a misfire

 

not to be a d**k but is there any reason why would you rev the f**k out of your cold engine??? do you have any understanding on how engine internals work?

 

I don't look at it as you being a ****! I appreciate you advising me that free reving a cold internal combustion motor is dangerous. Thankfully i already know that, that's why its only done for the purpose of the video, wasn't sure how well the cell phone would pick up the recording.

So with that cleared up does anyone have something useful to say?

 

Um, cold engine is running on an enriched fuel mixture. You should never expect it to operate at full potential until it's up to operating temperature.

Your "Free Revving" of that cold motor isn't doing you or that engine any good. Nor should you expect it to respond the same way it does when it's up to operating temperature and running on the correct a/f ratio.

There is nothing wrong with your engine, the problem exists with the user!

 

OK so its normal... because my last car didn't do it .... and this one didn't do it til a few weeks ago..... I try to let it run while I'm getting ready in the mornings, but some mornings only have a minute to let er warm up.... so something has changed with the car...

 

On a cold start the engine uses the maf for a/f control. It's not crazy accurate but gets the job done until o2s take over. my wideband reads rich A/f for a mintute and the other minute it runs lean to warm up the rest of the o2. After 2 mins it settles and hovers at 14.7

 

OK so ill just make sure it gets warmed up before operation..... do you think the plugs might need to be changed too?

 

I would do change the plugs and air filter and clean the throttle body , the buildup when it's cold hardens inside the throttle body and then loosens as the car warms up and the internals of the injectors as they get gummed up.

 

Ok so when I do my plugs I plan on doing the NWP intake spacer addon as well. Maybe change injectors at the same time???..... just take advantage of having the top of the engine all apart and clean out the T/B and I/M???

 

mine does it too. it didn't do it when it was new. I'm guessing it's a minor vacuum leak somewhere in the intake, because I hear a whistle when I accelerate when cold along with minor hesitation. It clears up after I've been driving for a few mins. It also don't do it for as long when the weather is warmer. I just let the car run for a min. or so before I get going. It's really nothing to worry about unless it causes you to stall.

 

OK then Im not going to stress about it. Ill just make sure to warm it up fully.... I'm glad to hear I'm not only one with this LOL.