cold start choking and stumbling
 

Sometimes when the car start up in cold start mode, the idle would sometimes start choking and sputtering like it want to cut off, then when it go out of cold start idle and the rpm come down, it just go back to idling as smooth as it always does. Anyone know what could be happening here:iono::iono:

Oil pressure building up for the cam phasers. Normal but annoying...

Tracy, now that you did mention that, this did start happening after I started testing the new cam phase tune, now I don't know if there was a problem that was getting worse that I didn't know about and the timing just happen to fall in right after what me and vince been doing, however, I did talk to vince about this already and he is stating that the cam phase should not affect the cold start stalling problem I am describing since the cam phase adjustments was not involved during idle or cold start.

Some guys that I am talking to are saying that it also could be due to turning off the rear o2's heater. I asked vince to turn my rear heater off because it was throwing the heater code when I uninstalled one of the factory o2 and used that location for easy AFR wideband o2 sensor.

My stock V6 does this all the time when it is below 20 out.
Very annoying, but it does smooth out after the idle comes down.
Hurray for Spring!

It never used to stumble and stall like it does now tho..:iono: I know during cold start and while the rpm is up it definitely idle rough, but this is no rough idle. It stall and choke and shake like the car is not getting gas and it want to cut off. It only happens rarely and for a brief moment, then once the rpm come down it stop while even the engine is still cold. Its really weird and don't know what to make out of this.

Oddly enough mine smoothed out a little after a bottle of dry gas.

what do you mean by "dry gas"?

Mine is verry loud at cold start!! Lol

its an additive that people put in to remove water that sometimes comes woth purchasing bad fuel or places that get extreme temp changes quickly cold to hot so you get condensation. Usually gets used more in diesel engines but also in gas as well

when you check your underwear and it's still dry, it was dry gas. :D

uhhhh kkkaaay:laugh:

So it's basically an additive such as injector cleaners and mystery oil and such...

Yes, some injector cleaners also remove water.

There was a thread about this on here a while back. The MAF sensors with a specific one letter code on them seemed to be an issue when the motor is cold.

Have a look here. It may be worth checking.
http://www.camaro5.com/forums/showth...esitation+cold