My '08 MC only has 24,000 miles on it. With the sport button on, mainly in 1st and 2nd gear, it hesitates a little and just doesn't accelerate smoothly. Isn't it too early for a fuel injection cleaner?

 

Forget the injection cleaner, sounds like you need a new high pressure fuel pump (HPFP). Many people have had the same symptoms and it ended up being the pump...

 

I would think it is. There is much debate but Mini recommends Tier 1 gasoline, Chevron, Texaco, Shell etc. Do you use these fuel sources or other cheaper stations? You may just want to run a couple jugs of Chevron Techron fuel injector cleaner through the car to see if that clears it up.

If that doesn't help maybe a code check is due or a visit to the dr.

Regards,

Pat

 

Yes, I do use cheaper stations - I'm going to change that + I just put in a little jug of Prestone fuel injection cleaner. It does seem to have improved, but I haven't been able to really *take off* in first gear yet.

Would the poorer quality gas explain the black build-up on my tail pipe?

 

I don't think the poorer gas quality has anything to do with the black on your tailpipe. I have the same thing on mine and my wife's car does as well. We put only Tier 1 premium fuel in our cars so I doubt that is the reason.

You may want to run the cleaner through the car for a few tanks of gas and then switch to Tier 1 and see if that helps. Mini does recommend it. (But like I say there is debate on the subject.) I get good enough fuel economy so I don't mind putting in Top tier.

Regards,

Pat

 

If the problem is carbon build-up on the intake valves, no gas additive will help. Gas never passes the back of the intake valves. It is injected directly into the combustion chamber.

If the problem has to do with your high-pressure fuel pump, it could be from the cheap gas, or it could be a faulty pump. If MINI tests your gas and finds it has too much ethanol, or is otherwise below standard, they may refuse to cover the pump replacement. If that happens, the cheap gas will have been a false economy.

 

Does the OP have a MC (as posted) or a MCS?

 

MC.

 

You do not have the high pressure fuel pump (and direct injection system) mentioned above. Techron may very well help you and it is not too early to add a fuel system cleaner. This is the same additive Chevron uses in its fuel. You could also have any one of a number of problems.

 

So I don't have direct injection... what do I have? As you may have guessed, I'm no mechanic. And this is minor issue, really. But, this hesitation/hiccup only happens when the Sport button is on and only when I really get into the gas in 1st and 2nd. It is a stick.

 

You have multi-point fuel injection. There are injectors for each cylinder and the fuel is injected in the intake, just upstream of the intake valves.

 

Since the sport button doesn't do anything to the engine other than give it more fuel with a lighter press of the pedal, you should see the same symptom with sport mode off if you mash the pedal harder. Give it a try to see if you can.

 

Cheap gas really does affecting the HPFP. Mine 07 S got it replaced when it has 31000km on it. Since then, I stop using the cheap China gas and only use top grade Shell which is from Singapore. Works well so far for another 10,000km with good mpg.

 

I second Techron Concentrate. You should be able to buy it at your local auto parts store, and although more expensive than STP or Prestone fuel injection cleaner, it works great. Like someone said earlier, Chevron adds it to their gasoline.

I would try a bottle, fill it up with Premium from a top tier gas station and give it an Italian tune up.

 

You might also take a look at your air filter. I'm finding my gets dirty rather quickly with all of the pollen that we have this year. Its really weird -- when I take it out to look at it, its mostly green.

 

That makes sense. I'll give it a try today. And, oh darn, I have to *mash* the pedal.

And to clarify, the Justa Cooper has no high pressure fuel pump? Some who have posted may not have seen that I have an MC.

Thanks for the help everyone! I do use 93 or higher octane at the cheaper stations, just so you don't think I'm a complete cheapskate! But I think it's time to start heading to Chevron...

 

If your intake valves only pass air then how do they get carbon on them. If they are partially open at sometime during the firing process then a gas additive should help. Never used top tier gas and I have had no problems,although I do put seafoam in the gas sometimes.

 

The OP has a MC, so there is no HPFP or direct injection system. The fuel is injected into the intake, upstream of the intake valves.

 

On the MCS (not what this thread is about) the carbon build-up comes from the PCV venting crankcase fumes. I'm not exactly sure of the timing, but I suspect that the fuel is injected into the cylinders after the intake valves have closed. So, it wouldn't get to the backs of the valves.

It seems that this is different on the MC, and fuel would go past the backs of the valves in an MC. The PCV still dumps oil fumes into the intake, but fuel additives may make this less of the problem it is with the MCS. So, definitely a reason to use a high-quality gas in an MC.

 

I think BMW notice this problem on most of the turbo cars but why only BMW will have 10 years extended warranty while Mini Copper S R56 only have 2 years standard? The replacement cost on this unit is more than US$4k min and this is part of the factor which affecting the resell value on most of the new turbo Mini.

https://wiki.bentleypublishers.com/d...MW+335i,+335xi

"Subject: BMW emissions warranty of the High Pressure Fuel Pump (HDP) has been extended from 4 years or 50,000 miles to 10 years or 120,000 miles, whichever comes first."

 

That fuel injection cleaner did the trick. Per robin and others, I will be heading to a better gas station from here on. Thanks for the info everyone!