Found out that exact situation happened to my MINI - driver said they "just about ran out of gas" getting to the gas station and then put $20 of 87-octane gas into it.

Next day on starting, it's misfiring (P300), engine lights, and after the cold startup it seems to hunt around for the right idle.

I'm new to MINIs - is that a common thing?

Thank you!


EDIT 27 September: It seems that gas was the culprit. I removed the 87 octane fuel as well as I could through the filter access in the back seat, closed it, and then put 5 gallons of 92 octane raw gas (C12) in the tank and it ran way better. Since it's not registered yet, I've not driven it on the street, but the idle has smoothed out and two cold starts have gone well. Thank you to everyone who pitched in with help.

 

you have a r56 S? if yes then yes it most likely is related, premium fuel in the S, running down to empty is not good either

 

If you have a turbo or supercharger then you can never go lower than 91 octane, 93 is best if you can find it

Mario

mQubed Motorsport RPM Power Tuning

 

Okay, that's what I thought. I know that the engines are finicky like a high school girl sometimes. (We have a 14 year old girl, so I know what that's like too.)

Question - I'm thinking I'm going to take out all the gas in the tank, replace the fuel filter, put in high octane gas, and then see what happens. Sound like a good attempt? Would you do anything else?

Thanks!

 

Hey Mario, thank you. What about raw gas? There's a place near us that sells ethanol-free gas and has an operation to fuel racing.

Ever use any of the octane boosts?

I think I'm going to drain the tank, replace the fuel filter and then fill with high octane.

 

Replacing the fuel filter is always a good idea. If the 87 octane is half gone you can add 100 octane to balance out the low 87 octane, or you can buy octane boosters like Torco or Boostane to raise the octane.

Mario

mQubed Motorsport RPM Power Tuning

 

You really don't want to be draining fuel if you can help it. One tank of lower grade gas isn't going to kill your car. As Mario states, octane boost or fill er up with better gas to dilute the old. Personally wouldn't mess with filter yet unless you are an experienced DYIer. Have read of too many folks replacing filter and then not being able to start car because they didn't do it right.

Just purchased used car, Prior owner sounds a bit fishy. Hopefully you don't have troubles beyond bad gas! Good luck.

 

I might have my DIY license, maybe more experienced than some and less than others. I've "refreshed" a couple of cars (German ones) and done almost all of my own work since 86. The fuel filter looks pretty straightforward compared to me, but maybe I'm missing something. I'm not too proud to take any hints.

PO told me today that his mechanic recommended changing the gas filter but the PO declined. It has 120K on it.

I called the local fuel shop and it turns out the manager there has a MINI and experienced the same thing in his with 87 octane. I think it's easy enough to pump out the old (throw that in the VW), replace the filter, check the tank out and make sure it's clean as long as its open, and then run some 92 into it.

What have folks done incorrectly with their filter? Thanks!

 

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Thank you Mario, I'll let you know how it turns out.

 

We have a VW GTI I wouldn't give it that gas,lol. I'm guessing the pumps aren't getting primed or they are not connecting them properly. Not sure as I haven't done a fuel filter inside a tank. My time with filters goes back to when you had them in line to the carbs on cars and my motorcycles. At 120K the filter is probably way past due.

Enjoy the DIYing

 

Hey Minnie we both seem to be old guys - good for us that we are still kicking.

You're right about the gas, it might be better suited to fueling the wood chipper or something. Now I just have to remember to put out my cigarette before opening the tank. *Joke.

I had to put an inline carb on the 500R my wife drives, because Kawasaki sold it without a filter. Maybe because so many people buy bikes and then don't drive them.

 

The engine is not being finicky it is designed to use a higher than 87 octane grade of gasoline. The engine controller can detect knock and dial back the timing to avoid detonation but the delayed timing means the engine is running sub optimally.

Given the engine's reaction to 87 and that probably the owners manual cautions against running 87 I think draining the gas tank then refilling with at least 91 grade gasoline is a good idea. No reason to replace the fuel filter unless it is due or you suspect the 87 gasoline was dirty or contaminated. Or you just want to replace the filter.

What about the engine air filter?

 

My comparison between a teenage girl and a MINI motor was my attempt at humor. I apologize.

The PO's mechanic recommended replacing the filter recently but the PO declined. I will see what it looks like when I open the tank. The air filter will be replaced to because it's dirty.