I have a 2004 mini cooper s. It has some upgrades such as: alta intake, msd igniton coil, alta light weight crank pully, alta 17% supercharger pully, and OBX header and exhaust. when i get on the car and get going and let out and get back in it the car will go to misfiring. Pull over restart the car it acts normal. the other day it didnt it and threw a code for running lean. Last night i went to pass a car and it went to misfiring but this time when i pulled over and restarted it it continued to do it i pull up the code it says cylinder 2 misfire i clear it restart it and still misfires says random misfire. Any ideas to what the problem is would be great. I'm thinking maybe fuel pump, fuel filter, or injectors ?

 

I suggest you run a compression check...easy first step, zero cost with a loaner tool....that way you can rule out a burnt valve from running lean early on...then I would check the wires and coil...maybe move the injector and see if the misfire follows the injector....you can also check the fuel rail psi with a loaner tool in many cases....again free.
With a 17% and the header you are likely running the edge of being VERY lean at WOT....but it's been done.
How many miles on the car? The fuel filter is pretty big....and often changed as a "feel good" diy....pumps do fail, especially if the tank has been run very low often....but usually run or not...

 

The car has 163,000 all upgrades have been on since 140,000. When I bought the car the ignition upgrade had already been done but I worry about it because it had the msd ignition back with junk autozone duralast wires. Would that cause the issue also? I will begin work on it tomorrow. What should the fuel rail psi be ?

 

Since it is easy, I would first look at the coil and spark plug wires. The MSD coils do not mount well unless the bolts are changed. Some vendors provide bolts with the MSD coils and some do not. The MSD could have been mounted with bolts that let the coil move around too much, causing damage to the coil or wires. Also look for corrosion at the coil terminals where the spark plug wires plug on. Check the wires for corrosion and wire damage.

 

Update: I checked fuel at fuel rail it was black. Pulled fuel filter out cleaned put back and wouldn't even start. Went to mini of knoxville replaced fuel filter. Started up but still missfired on cylinder 2. Pulled the spark plug out and the end was melted off. Replaced sparkplug still missfired pulled back out placed it on metal to make sure it was arcing it was. Put it back in the miss smoothened up. If I Rev it up it will stop missfiring. So only does it at idle. My theory is when I was headed home injector for number 2 clogged up burnt spark plug. Then filter started to slow down pressure caused multiple missfires. Now injector for number 2 is still stopped up causing issues could I be right. The plan is tomorrow to do compression check and move that injector to another and see what happeneds.

 

Sure looks like you plugged up a fuel injector with dirty fuel. Might be time to take all the fuel injectors out and get them cleaned and tested.

 

I get in the car this morning just to see and it goes to random/multiple missfires and missfire detected due to low fuel. I'm so confused

 

Random/multiple misfires would suggest that it's not a plugged fuel injector. Also, if you had mechanical damage (the reason for doing a compression test) in a cylinder, you'd get misfire codes for just that cylinder.

What's happening is that your car is going into limp mode. That's why your car re-starts smoothly until the fault re-triggers limp mode. A number of things can cause lean conditions, including intake and exhaust leaks (not to point fingers, but I'd check that OBX header), bad temp and pressure sensors, or bad fuel pressure regulators/fuel pump/filter.

It's probably time for a visit to your friendly neighborhood MINI specialist...

 

UPDATE: The fuel pressure is great no problem there.I checked the ohms on the coil pack they was great so no people with coil pack. So I that leaves the injectors correct ?

 

Go to harbor freight if you have one near you, buy their cheap compression tester, and do a compression test if you cant get your hands on a shop one. If they are pretty much on par and within spec, I highly suggest a cylinder leak down test. This can tell you if a valve is bent/burnt valve/head gasket/ hole in piston. Using that 17% is huffing in a lot more air, and if they are stock injectors, and no tune, you probably ran her lean, and burnt something up. Also if you are running stock plugs, and are beating it up, that air is really heat soaked due to being a very small pulley, which can cause pre detination. Get those injectors flow tested, they do have filters in them that could of possibly been gunked up, but if you're in that deep, might as well get bigger injectors, and a supporting tune.

 

No - as zippy stated when you first posted and helix also pointed to - you need to check compression to see if there is any mechanical damage. Run a compression check before you spend more money randomly replacing parts.

 

UPDATE: cylinder 2 compression was lower than rest. Looked In cylinder and there is some sort of fluid on top of piston may be gas or antifreeze can't tell.

 

Might be oil too if bad rings or broken piston. If antifreeze, your oil would be all milkshake like. I think you ran lean based on the melted plug and the unsupported mods. Lots of detonation borked your piston leading to low compression and "liquid" on piston.

 

Next things to do is a cylinder leak down test. This can help determine exactly what that fluid is and where it's coming from. This means taking off the coolant cap, the oil cap, dip stick, and take off the intercooler, and have a good set of ears. Make sure that the intake and exhaust valves are closed, and at this cylinder is at top dead center. When you perform the test, listen for air. If you see air bubbles in the coolant tank, blown head gasket, feel/hear air in dipstick or oil cap, bad rings, feel/hear in exhaust or at the intercooler horn, bad valves. Find out what liquid that is, it may be built up fuel from not ignition do to a bad plug.

 

I got tired of messing with it and took it to European auto garage in knoxville. Their mini specialist said it's antifreeze coming from the head gasket. Said they put a camera in there and tried starting it and watched it come in. And said that there isn't a good way to fix it that will last long said to put a new motor in it. So I just picked it up. Is that true ?

 

They are saying there is no good way to fix a head gasket? Usually it's just removing the head and replacing the head gasket - not that difficult of a job but lots has to come off. If there are cracks in the head or the block - then yeah you need to replace those cracked parts. Did you overheat this car? Does the car overheat? What color is the oil on the dipstick?

 

Sounds like they are trying to make some money. They haven't even removed the head to have it checked. It will more then likely need to have the head cut, or worse, a new head, but unless the block is cracked, or theres a hole in a piston, there shouldn't be a reson to yank the whole engine out.

 

The leaky HG wouldn't melt the plug off. I think there was something before that. If the block is bad and the HG is leaking a new motor would be the way to go. I think I would pull the head and have a better look before committing to the new motor.

Of course running with a bunch of coolant in the oil is pretty hard on bearings. Maybe the latest shop is right. Just replace all of it so you aren't doing it again in a few months.

 

Lol...RUN
a headgasket is a few $, plus labour... Maybe $1500
YPU will not be sure if the head is cracked and needs to be swapped or fixed also till it is off...
But to replace a motor for a suspected headgasket?!
Maybe the plug melted cause the motor is junk....possible... But they should have more info to guide you.

 

The car was overheated once just for a second or 2 about 15,000 miles ago. The oil color is normal. Cylinder 2 compression is 39psi

 

The compression for the cylinders in order are 144 39 120 and 160

 

Best case you just have a bad valve, worst case the piston/block is bad. With compression that low , the misfire, and the melted plug, it's not going to be just a bad head gasket. It still ran ok so hopefully it's just the head.

The head is easy enough to take off so that shop just doesn't want to deal with it. If you could take the head off yourself it would be nice. Would suck to pay someone to take it off only to have the piston or block be bad. But that is probably still your best option.

So like zippy said, around maybe 1500 to do just the head, or a minimum of a couple thousand for a used engine. New engine, or all new parts gets to be more than the cars worth, even more so if you have to pay someone to do the work.

 

I've decided to pull the head off. I was wondering if I will need new head studs or will these be okay to reuse ?

 

get new

 

They are stretch to tq studs...so examine them...officially they are one time use...but many folks reuse them if they look OK.