Sputtering on cold start
 

Ok, before the flaming begins, I searched and read all the threads on cold starting issues. I am just looking for a little guidance here. Replaced plugs, coils, wires two weeks ago. The car ran great for the first few days. Came out to start on a really cold morning, 9 degrees, rpm's spiked and engine sputtered for first couple of minutes. I understand the rpm spike is normal, and I assumed the sputter was too, since after the engine warms up it runs perfect. It is now sputtering everyday, on all cold starts, even when the outside temp is near 40, so I am assuming there is something else going on. Still runs great after it idles for a few minutes. Can anyone offer some possible problems/things I should be looking for? Air pump, bad coil maybe? No codes and no cel, so I am at a bit of a loss and would like to avoid the dealer at all cost. Thanks!

Come on guys! Somebody, anybody. I will add that I cleaned the MAF and TB as well..ECU reset maybe? ESS cleaning? Gonna give all these a try tomorrow...will the comp store codes with no cel?

Really? You want customer service inside of 1.5 hours?

https://www.rx8club.com/trouble-shoo...xhaust-242428/

I was hoping for it within 1.5 minutes, haha. Really though, thanks for the link, it appears I need to try a few of the things I outlined above and see if that clears it up. Just has me stumped that it only does it for the first few min while cold and right after coil,plug, and wire change. Love this car, but its little quirks are enough to cause nightmares sometimes.

Ok, so I cleaned the ess and reset ECU, still misfiring on cold startup. I have been reading on here that it can be considered normal, since the car runs rich, but it did not start until a few days after changing coils and wires. If I blip the throttle a bit the engine shakes and sputters much worse for a few seconds but then levels off and runs just fine.

Just to reiterate: new plugs, coils, wires, clean MAF TB, ECU reset and cleaned ESS. Check all vaccuum lines and all seems good to go. Car runs fine after initial warm up. Still doesnt seem right to me. Am I just being paranoid? And can the local parts store read stored codes in the ecu if no cel is present?

check the MAF.

ok, what specifically am I looking for on th MAF? I cleaned it with contact cleaner last week. Should I be checking the seal? Thanks!

bro dont worry about it. My first engine used to sputter at very low temps for a min or two and then quiet down. Now my new engine is 5k old and the other day on a very cold day it was -15 it did the same thing but runs just fine after. I guess its a warm up procedure from the ecu

I can drive mine around as soon as it turns over, but if I ever rev the engine when there's no load (even if it's a tiny blip), it WILL smoke and sputter for 20-60 seconds. I smoked out a cop once, it was horribly hilarious.

I think it's because it runs REALLY rich at start up, and if you're not applying load (using the fuel) then it becomes too rich to ignite (probably below 11 AFR), and bada-bing- bada-boom! It sputters and smokes until it can properly burn all the fuel*.

I just drive it even harder (under 5K) and the smoking goes away faster, albeit in a bigger poof cloud.




*Remember, the exhaust ports in our car were so placed to RETAIN unburnt fuel, and re-use it into the next cycle. Even if it means retaining more than it needs.