Cold start troubles
 

Hi all,

A couple of weeks ago my car was running awesome, but recently i've been having issues with cold starts. (Not cold weather). When I start the car up, sometimes it immediately stalls, but usually it just bogs down at a really low rev and I have to give it some encouragement for 10-15 seconds.. usually resulting in a lot of backfires.

After she gets going she idles fine.

Could this be my spark plugs going out? Or possibly a vacuum leak?

I've searched but most people have crazy standalone setups or ports jobs and need to adjust their idle, but I have a pretty much stock S5 turbo and the problem only surfaced a couple of days ago.

I would check your plugs for fouling, as well as reccomend checking your TPS. If anything, if it has been a while since your last tune up, I would get new plugs and wires. Normal NGK Oem parts will work just fine. But also check for spark. Although it is starting, thats not to say you're not getting a weak spark.

Some additional information from tonight.

I've been getting frequent 'add coolant' buzzers.. about two or three every time i drive. I suspect air bubbles but i'm sure all of you guys understand my anxiety.

Tonight it was about as cold as it gets in San Diego (not very) and I had a pretty abnormal amount of smoke on startup. I don't think it smelled like coolant and it definitely wasn't as thick as I'd like to believe coolant smoke is. The smoke went away once the car started running right again after about 10 seconds of encouragement.

I'm guessing the smoking on startup is probably unburnt fuel due to weak spark, but i guess I'll only know for sure once i've changed the plugs/wires.

How often do you guys change your wires and how does one tell whether or not it's necessary to do so?

The bit of smoke at start-up seems normal. Are your plug wires cracked, melted, broken, sheared, etc...? How old are your plug wires? Do they function properly??

Alright I'm getting really anxious.

The car now blows smoke on hot starts (car off for ~15 min). I thought I caught a whiff of coolant but I can't really say. My add coolant buzzer still come on intermittently. I'm going to do the champagne test this weekend when I have time.

ive been having the same problems when i start my fc on a cold start. when i first start it itll run for a few seconds then stall. when i start it i have to hold the throttle down a little bit for like 30-60 seconds or it will stall. my add coolant light has come on a few times also. its pretty irritating because i dont know why its doing that

Pin 2I at the ECU is for the Water Thermosensor and is responsible for the amount of fuel at startup. If it is out of spec, it will inject too little fuel on a cold start. The pin should read 2 to 3 volts cold and .4 volts engine completely warmed w/key to on.