My 06 mini r53 has been running great since I did some work to it probably 1500 miles or so ago. I replaced the clutch, pressure plate, throw out bearing, water pump, thermostat and housing, belt and belt tensioner. Also changed the oil in the supercharger and transmission.

On my way home today, I had to stop for gas, so I filled it up with the 93 octane from BP (as I have before). I left the station and drove down to a pharmacy less than a quarter mile away. When I was pulling out of the pharmacy I thought I noticed a little miss. On the 2 mile drive from there it got progressively worse and would barely idle or rev up when I got home. I suspected the possibility of water in the fuel so I went and bought some additive that is supposed to help with water. I put it in the tank and went for a short drive. It didn't help and doesn't seem any better.

If its not bad gas, what should I look for? Does it take time for the fuel additives to work?

Any suggestions are appreciated.

 

Can you check fuel pressure?

Check engine light on?

Any pending codes?

 

A lot of stuff going on. I tried to start it today when I got home and it took a few tries before it would start and it idled very rough and would die. I pulled the codes and they are:

P0442, P0301, P0171 and P0300. It has to have something to do with the gas I got. Is there an easy to pull the line from the throttle body and feed it some known good fuel. It was running too good before the fill up.

And yes the Service Engine Soon light is on.

Suggestions?

Thanks!

 

P0300 and P0301 cylinder misfires.
P0171 - System Too Lean (Bank 1 of 2).
P0422 Main Catalyst Efficiency Below Threshold

Could be a simple as the gas cap since it happened after your fill up. You should check all plugs and wires. Check the coil connectors.

 

Here is something as a possible cause for P0442
https://www.northamericanmotoring.co...ent-p0442.html

 

As a FYI there are basically 3 reasons why a cylinder misfires;

1. Loss of spark
2. Air/fuel mixture too unbalanced to ignite
3. Loss of compression

A bad coil would usually affect all cylinders so try to narrow it down to whether it's just one cylinder or all of them.

The lean mixture could be caused by an inoperative fuel injector. It could be clogged. A dirty filter or leaky pressure regulator could also be a cause.

The third reason loss of compression could be caused by a leaky exhaust valve or a blown head gasket. This is a known problem on the MCS.

To isolate the misfiring cylinder, you could disconnect one spark plug at a time at idle. When the idle speed stays constant, you've found the misfiring culprit.

Just some food for though. Good luck and keep us posted.

 

Well...

P0300 is random misfire.

This with the p0171 lean condition would have me check fuel pressure (with a gauge..) it's the only proper test to do. Frankly it sounds like the FP crapped out.

Take a look at live scan tool data. Make sure ECT and IAT are reading true. These can under fuel the car if they are reading super high. (Hot)..

One other possibility is a bad TPS, if its stuck at 80% or greater it can put the car in de-choke mode and shut down the injectors.

 

Another way to check wires is to spray them with some water at night, while the engine is running to check for any electrical arcs. If you see any, then the insulation around the wire is bad, and you are losing spark.

My Mini was misfiring last week so I replaced the wires, and it runs well now.

 

So I replaced the plugs and wires today before even trying to start it up. When I started it, it fired right up but then idled down and starting missing and died. I started up again and was able to get it to above idle but I could tell it was missing (I'm not sure the plugs and wires did anything to help). The yellow triangle with the circular arrow at the bottom of the speedo came on but I tried to let it warm up some anyway. I would shut it off and start it up and the light might be on or off. The Service Engine Soon light is still on from when the problems started the other day. As I let it warm it seemed to be running a little better but not great. I was able to drive it about a 1/4 mile up the road and back, and it seems to run better at about 2000 RPM or better and best at 3000 or better. It seems that if you let the throttle off quickly, it will idle rough and slow and slowly idle up to normal but still be rough. I checked the gas cap for about the 5th time. It never really clicks when going on, but I tighten it pretty good. I even put just a dab of oil on the "O" ring just to help it seal, but I am not absolutely sure it's doing what it should.

I am no expert by any means, but does any of this not sound like bad gas?None of the posters had indicated that they were thinking anything like that?

 

Ok..

First, forget about the gas cap code.. That's not the issue.

Second. Stop spending money on parts. You'll only spend yourself into a hole.

Yes. It could be bad gas.. But... How can you test for fuel quality?

Here is a test we do at school.. You'll have to get the fuel sample safely from the rail.. If that sounds scary... Please have a professional help you.

1) get a 100ml graduated cylinder, fill it with with 90ml of fuel.

2) add 10ml of water to the 90ml of fuel in the cylinder.

3) put your finger over the top of the container and give it a good shaking, 10 secs is more than adequate.

4) wait about 10mins for maximum stratification.

5) the ethanol(alcohol) will mix with the water and settle to the bottom of the cylinder, the gasoline will rise to the top.

6) for this example lets assume that the line where the gas meets the ethanol is at 70ml. 70ml of ethanol minus the 10ml of water you added equals 60ml of ethanol. There were 90ml of fuel to begin with so, take the ml of ethanol and divide that by the total ml of fuel. ( 60ml / 90ml ) = .66

Your fuel is 66% ethanol..,

 

Very smart Dan. I'm calling this the new thing I learned today. ::thumbsup

 

Thanks Dan...I'm not scared to get the gas from the rail..I just need to know how. According to what I have read there is a shrader(I know what the valve is, just not how to spell it) valve at the end of the rail (correct?). I assume this is where I need to get the gas from? Also, my
mini is the S version, so to gain access to it I need to remove the intercooler?
Once I gain access, where can I get the matching fitting for the valve?

I guess another option is to assume the gas is bad and drain the tank? If I were to go this route, how is the best way to do so? Remember I have a full tank as I had just filled up...

Thanks for the advice..

 

My suggestion if you want to drain the tank....
Pop out the rear seat....
The open it up like you are going to change the fuel filter....
Then siphon out most of the fuel....
Replace the filter, seal it up.

 

I removed the fuel filter and siphoned all the fuel from that side of the tank. I had a full tank but only got out about 9 gallons or so. How can I get the fuel from the other side of the tank? Hopefully I don't have to remove the fuel pump? Also the gas looked pretty good. I siphoned the first part from what I felt was the bottom of the tank into a clear container and didn't see anything suspicious. I can look into the tank and see just a few little pockets of water I think.

Also the filter is Black and had a lot of black grunge in the filter canister. I called around and can't get a filter today. I guess I'll order it from Pelican. But until then, I put some gas in to an old windex bottle and did a micro pressure wash on the filter actually getting it reasonably clean. If I stop up one of the holes and blow into the other, it appears to be free flowing enough for now until I can get the new filter kit.

 

Ok, i pulled the fuel pump and siphoned all the gas from that side too. The last bit I siphoned into a small green tinted container about the size of a large drinking glass. There was probably 3/4" of water in the bottom out of the 6" or so in the container. I then took some clean rags and wiped the inside of the tank clean and dry as best I could.

I put everything back together and hit the starter. It fired right up and idled good. As it began to warm a little it did begin to miss a little but not like before. It seemed to run well about 2k. I let it warm up completely and it seem to really smooth out. I took it for a test drive and it ran great.

Not really sure what the problem was, but seems better now.

 

Glad it sorted out.

Now, contact your local news outlets about the station and contact the state department of weights and measures.. I'm not kidding.

 

+1
Sounds like that gas station dumped a load of 87 or worse, mixed with or at the very least, saturated with water.....
Since modern fuels are mixed with about 10% ethanol, they can hold lots of water...that is why you simply don't hear of many water/ice issues with fuel anymore....the fact you found liquid water...not in suspension, means there was lots....