Starting to notice that when the car is cold and at first start of the day, it fires immediately, high idles 10-15 seconds, then stumbles & sometimes dies. Restart takes some cranking. When it fires, it stumbles for a sec, I feather the throttle and it runs perfectly after that. Next starts are very easy, usually one bump of the key. No codes yet.... EGR? EGR solenoid? Injectors? What systems are involved in the cold start/cold idle?

 

test temp sensors, fuel pressure, throttle position sensor. 4th Gen LT1 F-Body Tech Aids

 

Cant find any issues with anything. I decided to go ahead and order a FPR, EGR valve and the EGR solenoid. I also went ahead and installed the NGK Iriidium plugs you suggested. It started great this morning, cold idled perfectly and idled down as it should....about 5 minutes into idling it stumbled once pretty hard, caught itself and ran fine after...

 

make sure your coil wire is plugged in all the way. i had one not go on all the way and it burned the end off the wire and ruined the coil.

 

Ok, will double check it tomorrow. Parts should be here tomorrow so Im hoping one of those things will help. I know throwing parts at a problem isnt really the best way to approach an issue... but with 150k on alot of these parts, it sure couldnt hurt.... It does seem like theres imptrovments with each step I take. Thank you for the help.

 

have you cleaned the iac motor/valve? can't remember,,, lol

 

Do you notice any changes when the weather is changed in your area? I am asking whether this has anything to do with humility to dryness, because you said when car is cold.

 

I have not, but it was replaced a year or so back when I originally purchased the car. Do you think its worth looking at again?

 

Not really...just when the engine is cold after sitting overnight for the most part.

 

probably ok.