I have not seen any of the JCW owners complaining about the cold start issues. Is this true? Perhaps the larger injectors and programing is the key. Any input?

 

Nope, we're cursed too. My 05 MCS with JCW and my co-worker's 05 MCS with JCW both exhibit the same problem described here.

The dealership is actually working with MINI PUMA to see what's causing this on my car. Last week they kept the car overnight so they were able to experience the fault after the car sat. They did. No codes, so they called MINI who instructed them to put a fuel pressure gauge up to my fuel rail, then waited until the next morning to try again. They reported that during the stumble, the fuel pressure across the rail does indeed drop. That's the cause. MINI suggested they fit a new fuel rail and injectors (JCW injectors in my case) and try again. They returned my car while waiting for the parts to come in, and are taking it back tomorrow to fit the new parts, then keep the car overnight and see what happens.

According to the parts man, the fuel rail has not been superceded or redesigned, so I'm not too hopeful this will make any difference. But at least, MINI is spending some money to look into the problem.

 

Thanks for the info. Thought I might be on to something. Fuel rail sounds like a long shot. I would think the regulator would have more impact.


Are there after market regulators available? Ajustable? Hmm new angle to look at.

 

I have not experienced this problem, but My car is only 6 months old. Is it more likely to occur in cold weather?

 

Yes, actually I forgot to mention that the dealership is trying a new fuel regulator too.

The stumble seemed to crop up after I had the car for 4-5 months, and doesn't matter if it's hot or cold out.

By the way, where is the fuel filter located on our cars?

 

I have also experienced the cold start stumble and it happened to me in the middle of the summer. My car doesn't do it very often though, but it did stumble a bit while sitting at a stoplight on Sunday afternoon after driving at the track all day. I was kinda surprised for it to happen then as I had previously only experienced it in the morning.

 

We've had our JCW since April, and it started the cold start stumble in late May or early June. It normally does it every morning on the first attempt at starting, after that it is fine. It has never gotten worse. Because of what I have read here and the fact that it is consistent, I have not worried about it. I am almost due for the first serveice stop, so I will mention it then.

A_Sr.

 

Over time our MCSa has gotten worse. This past weekend the first attempt to start it resulted in it starting in the "limp" mode. Check engine light on etc. The biggest concern for us is the hesitation. Unless it is fully up to operating temp there is a several second delay when the throttle is depressed. ZReal nice for merging into traffic.

 

I've gotten to the point (only had the car for about 2 months) that I will smoke a cigarette before I go for a drive in the morning. Since I don't smoke in the car, it gives it time to warm up and when I get in, there is no problem with hesitation. One time when I left work, I was pulling out of the parking lot and the car had NO POWER. With the gas pedal basically on the floor, it accelerated like someone was pushing it. Then it finally caight up to itself and took off.


I don't have a dealer appointment for a while, but i'll be sure to mention it so at elast it is documented.