2009 C4S Manual, 43K, daily driver. Sitting at red light, radio on, then no go when i pressed on gas. I guess I could have stalled it but i really do not think i did. Tried to crank, everything was dead. Removed key, reinserted key, cranked and started. All was fine for the rest of my trip home. No CEL. Thoughts?

 

2009 C2S 191K miles

Never happened to me, although I have had odd stumbles at red lights. Maybe someone here will have a better answer, but this is what I would do:

1 - Get the codes read. Any Autozone will read your codes for free. Not all codes thrown will flip on a dash light.
2 - You may have a coil pack going bad, although I doubt it with such low miles.. if it is, you will have this happen again probably when hot and it will shake the car. Code reader will tell you misfires. No need to change anything until you are sure and with a coil, you will know... oh yea.
3 - Run a high concentration of Techron for two consecutive tanks
4 - With the Techron, run many Italian tune ups... high RPMs for minutes at a time (while driving)
5 - Clean the throttle body and MAF sensor. Buy a can of MAF cleaner, remove the airbox, remove the MAF and spray the heck out of it and shake it dry, spray the butterfly in the throttlebody with the butterfly open (with your finger) and wipe with a rag and get the edges of the butterfly.
6 - Stop using cheap gas... use only Exxon, Chevron, BP, Shell, or other "Top Tier" gas that has extra additives

Overall, I would assume your fuel delivery/system is gummed up due to such low and I suspect, unaggressive use. If I am correct, you probably have an unsteady idle too (this would support the needed cleaning effort). For a period, years ago, I was only driving a very short distance to the train station without even fully heating the engine. When I replaced my spark plugs, they were all carboned up and I could knock them on the table and leave carbon dust. These cars require aggressive use to stay clean.

Peace
Bruce in Philly (now Atlanta)

 

Being in Philly, I sure wish you were still here. I have a nice shop btw, if you are ever back in town. Anyway, I'll follow your advice. Although, no CEL and no "unaggressive use" by me. I regularly beat the heck out of her and normal shift points are 4500-5000 rpm. I did just run Techton two fills ago a 1/3 tank. Ill do it again and follow your instructions for fuel selection and MAF cleaning.

 

I've had it happen 3 times now over the last 11 years. All around the same area near a Lowes/Samsclub/Walmart. Never anywhere else. A bit of a rolling stop like when you come up to a stop sign and it shuts off. Turn the key and it fires up immediately.

Given that it has happened 3 times over 20-25k miles and only within 1/4 mile of that location years apart I suspect some kind of electromagnetic interference. Too much of a coincidence to be anything else.

 

I've had something sort of like your situation in my truck. The truck was running and drove fine, then it completely died at a red light, no accessory power, no dash. After 10-15 secs with the key out, I got accessory power back. Someone nice help jump start me. Luckily I was close to home and went back and got my 997. It ended up being a defective battery. Good luck trouble shooting.

 

I have the same car, 09 C4S manual. This happened to me maybe 3-4 times before in a variety of stop-n'-go scenarios. However, I admit that I had stalled the engine on all instances. The car will not start unless the key is removed and re-installed for some odd reason. Just don't stall the car.

 

fuel pump??

 

I have 2010 4S manual and this happens to me twice a year. Come to stop sign and engine will softly die. No idea why and I kind of just let it go.
If it starts happening more and more it is a sign of your high pressure fuel pump going bad.

 

Yeah, stupid question but did you just fill up?
The reason I ask is because my car HATES having a FULL like FULL FULL tank. It only acts eccentric for the first run after I overfill it slightly, so now I try to click it off before it gets fully full and never top it off.

 

I had similar situation but in my s4 it was the ignition switch