Hi, I'm not usually a poster in the 1st gen forums... haha, but this one's not for me. It's my boyfriend's.

He's got an 06 MCS 6 speed with a few mods. 55k miles. In July the alternator died on it, but we couldn't afford a replacement at the time, so it sat until about three weeks ago. We finally got one and he installed it himself (with the help of a few others). The car started up great and has run excellently until about a week ago.

Now whenever he starts it after it's been off for 6+ hours it stumbles pretty badly. It flops between around 200-600RPMs and shudders for a few seconds before it bursts back to life and usually it acts normal afterwards. It starts great once it's warm. Pretty sure it hasn't actually stalled, but it gets close almost every day.

Once, when we went to pull out of our driveway (we live on a busy road) it nearly stalled when he had taken a left. It scared us both pretty badly as there was oncoming traffic. He floored it until it regained power, which was about 2-3 seconds, then it acted normally again, as if there wasn't a problem before.

Now, what is it that we could be looking at here? If it helps, apparently the car had a full tank of gas while it was sitting and is still on that same tank. Is it possible that it's just the gas?

I also apologize if this has been discussed before, but I searched for a good 20-30 minutes for an answer before I gave up and posted this. All the threads I saw were just people explaining the issue, but I saw no resolutions. I may have missed something though... thanks in advance for any replies. I appreciate your time!

 

I had what was called the cold start stumble and stall at initial start up for about two years. Would start perfectly fine second time but there was that habitual not wanting to start first attempt....pita more than anything else...I am just picky.

Finally went away after adding JCW injectors, a new DME and a JCW Tune....Now starts right up in a less than a split second soon as the key is barely turned...

I would start with spark then fuel. Working your way thru coil pack checking the connectors for corrosion, the plugs, the battery. Then checking fuel pressure ect.

 

My R53 had similar cold start issues that my friends and I refer to as the MINI Flu. However I just had my car tuned by Way down at WayMotorWorks last week and it completely alleviated the issue with cold starts, stumbles, etc.

 

Kinda make you wonder if it's a programming issue with respect to the crappy fuel we need to use now. Since the JCW tune I can report the same results.

Especially since in many cases, symptoms were somewhat seasonal with respect to when the winter "conditioned fuel" was being pumped....if it was really cold out, no problems. But when ambient temps ranged between say 50 and 60 degrees in the spring and fall, the flu seemed more apparent.

 

Thanks a bunch for your feedback. We will definitely look into them! I know he hasn't had his car tuned since he's put on all his mods (right after he got the car in 06).

He filled up again yesterday and it hasn't stumbled since, so I can't help but wonder if it really WAS just the gas. Maybe it's just been in a good mood. We'll see!