Over the past few weeks my car has been misfiring on start up and then the problem seems to flush itself out. My first though was that there may be a loose ground or something in the ignition system, but after checking the spark on the cylinder that was misfiring I found no problem. Then I though that it may the dirty fuel injectors, so i went to the auto parts store and bought some injector cleaner. The bottle said it would treat 21 gallons of fuel, but the mini's tank only holds thirteen, so I poured in half the bottle into an almost empty tank and then filled up. I drove around the rest of the night with no problem. This morning when I woke up to go to class, the car would not fire. I know that the problem is not a dead battery because, the it was turning over(until just recently, because of so many failed attempts to start it.) I am worried I may have clogged the injectors. Or F*** something else up.
Anyone have any kind of advise that could lead me in the right direction?

 

do you have fuel pressure at the schrader valve on the rail?

 

Just two days ago my fuel pump stopped working. Turns out, the lead to the pump had come disconnected. Fuel pump works fine when it has power...

I had the same symptoms you describe.
Access is under the rear seat. Easy fix if that's it.


dan

 

Okay so this morning I tested the pressure at the fuel rail, and it was spot on at 43 psi. So there couldn't be a problem with the fuel pump or rail, and I assume since there is pressure in the rail then there is pressure at the schrader valve. after I check the spark from the coil pack which is fine as well. I haven't checked the spark plugs but they are practically new, so I don't think that is it.

Does anyone have any suggestions as to what the problem may be?

 

do a compression test. if you have spark and fuel pressure the only thing that comes to mind would be a blown head gasket, ecm, camshaft/crankshaft position sensor. did your check engine light flash or stay on? if your car was misfiring it could have damaged your catalytic converter and with no exhaust flow your engine wouldn't start. there are a lot of things that could be wrong. hopefully your still under warranty and can get it towed to the dealer. good luck and let me know what you find out.

 

Well I found out what the problem was, when I pulled the spark plugs they seemed to be heavily fuel fouled. So after replacing them, the car started fine. However I'm still worried that this may only be a temporary fix. Does anyone know what might have caused these to become so dirty?

 

Woops, never mind, guess you found it and posted while I was typing!

Goldrush, did you ever get going? What about a distributor? Is that past the coil where it could disrupt the spark before it got to the plugs? (sorry, not a mechanic myself and don't have memorized the order of the parts in the elecrical system) I had a car that the distributor went out and it cranked and cranked like you described, never fired up tho, I thought it was the fuel pump first off too.

Tech guy is right- make sure you have air going in and out, fuel, and fire all the way at the plugs. If not, then hunt from there based on what is not at the cylinders. If you have all the 3 ingredients but no life, then you have to look at the other things he listed off.

Let me know if you get your MINI going- I know this has got to be frustrating.

 

How are they fouled? Rich? Do you have enough air getting in? Check the air filter and the exhaust- if the cat. converter is failing it isn't breathing good and air isn't flowing enough. Make sure air can get in and out.

Any smoke in the morning when you fire up? If yes and it is blue you have a gasket going and oil getting in the cylinders.

 

Thanks for the advise. My dad has been driving the car for the past year, so after hearing what u said I went out and check out a few other parts of the car, and it looked like he's had the same air filter in for a about two years, this I think may have been a large contributor to the problems. I replaced it with an alta filter, so hopefully it will solve a few of my problems.

Techguy, how would I go about checkin the cat for proper flow?

 

On the Cat.Converter- how does the car feel when driving under a load? Like up a steep hill? The higher revs the engine has to turn = more air must be moved through the system. Now, you did just replace the air filter, so that could be part of it, but does the car feel sluggish under these circumstances? That is one simple clue, if your MINI groans about, "Oh dear Lord I am SOOOOO exhausted!" when going up a hill, it is asthmatic and cannot breathe, which can be the air filter or also the cat. converter. So, go drive up a hill now with your clean air filter!

What sort of gas has your father been running? I know it has been flogged to death here, but if he has been running too low an octane he might not have been getting good complete combustion at the proper time in the cycle. That'll foul plugs I'm pretty sure.

Maybe someone else will post- I don't know the answer to this, but if your plugs were that gorpy- to the point they wouldn't fire- then obviously you aren't getting good complete combustion and you are sending that down the exhaust pipe and on to the catalytic converter. So that could shorten its life, would be my reasoning, another reason to check on that end.

Another consideration, has this car been modded at all? Anything that could throw the timing askew or alter the air/fuel mixture or be making the car computer compensate for something odd in any way? When the car is started, do you just turn the key or are you putting your foot on the accellerator and giving it gas at the same time, which should not be an issue with fuel injected motors- but, "flooding" it prior to it getting started up could foul plugs too, because it couldn't possibly burn all the gas that might have been dumped in there, which would mean incomplete combustion and carbon buildup on the plugs.

Now that I have said all that, the plugs were black, right? Excessive carbon from incomplete combustion? 'Cause if they were a different color we gotta look a different direction.

 

The plugs looked kinda like this, and smelled like fuel

 

Rich. Too much petrol and not enough oxygen to burn it all.

I did think back to your mention of injectors too- you thought they might be dirty; if they ARE, they might not be atomizing the fuel into a fine mist that burns up so easily... Argh, so many possibilities. But it is a good start that you found a clogged Air Filter.

The simple thing to do is, now that you have a nice clean air filter and good gas in the tank, put in nice clean plugs (which I think you said you did, right?) and take a longish drive. Give the computer some time to think things through, motor up some hills if you have them in your area, and see how she goes.

Take a cell and let someone know what you're doing, just in case...

After your drive, let her cool off and then take another peep at those plugs. Do they still look new-outta-the-box? I hope so! However, if they are already starting to soot up and you are still smelling excessive gasoline stinkums, the first thing I'd look toward is the catalytic converter. Somebody is going to have to tell you exactly how to figure out if it has croaked, because I can't, except to tell you if it has totally croaked the car just WON'T go up hills - it will literally stop even if you are giving it all the gas in the world. My grandmother's car did it, so I have seen it first hand. But if it is only partially clogged, I don't know how to tell about that. I have seen in another thread a clue might be a rotten eggs smell to the exhaust. Sulfer smell, that is. Maybe you could do a search on how to tell about a Cat. converter?

However-

But if the plugs look ok, drive for a few days, check again, drive and check, drive and check. If they keep looking good, you're good. It was the air filter, or the gas the car has been given in a previous life, or whatever. I wish I knew more for you.

 

if your car really was misfiring it would cause unburned fuel to buil up on the plug. i'm pretty sure your cat is ok. the way i know to check it is to hit it with a rubber mallet. the only problem is i forget if it should sound hollow or solid....oh well. for now continue to drive the car. make sure there are no stored codes. no starts and misfires are a b**** to diagnose. i have 2 cars i'm working on right now.... one that wont start. and one with multiple misfires . now all you have to do is enjoy your mini and wait for it to get sick again. when that happens you'll know where to look first. scan it for codes and check the spark plugs.