So my story is this, I brought a R56 JCW Mini last month and thought it was a good car only to be left with allot of problems. I have just had fixed the timing chain, which cost me ｣850, but my main problem is a misfire, but get this, there are no fault code coming up, and there are no check engine light displaying, as far as I can tell, there is no problem with the car, apart from I cannot fixed this bloody misfire.
I have change the the spark plugs, and all 4 coil packs, but i知 still getting the misfire , the only other thing I think it could be is the fuel pump but I知 just not sure where to start anymore, i知 at my wits end with this bloody car, and I just do not have anymore money to fix the dam thing, not at the moment anyway.
The misfire only happens in the higher gears 3, 4, 5, 6 gear, 1st and 2nd gear work fine with no misfire at all. Would anyone here be willing to help me out, who have more experience with these cars then me, I live in the Kent area, Medway.
the first timing chain on one of these i ever done i done it by the book and believe me they must be done in a set way with good parts used, also all sprockets must be changed and the special locking tool must be a good make one,, i try'd a cheap ebay timing tool for ｣50 put car back together it was retarded on timing by 2 to 5 degrees,, i now use a laser tools kit i picked up for ｣140 and never have any issues, i have also seen cheap ebay timing chain kits from china or where ever where the timing chain guides slot together and these cheap ones come apart,, i only ever fit FAI or febi bilsteen or dealer only parts and the full kits including the vvt sprockets as these wear and allow chain to move under load and cause misfire fault codes, also have seen cheap timing chain tensioner that lock up and cause issues under load, tou will find the misfire is still there in 1st and 2nd but because of nature of the load in the other gears it will show more with high loads,,
i have also seen cars that have been driven for a number or months years with timing chains stretched to the point where the edges of the valves just touch the piston enough to lightly wear the valve guide or and bend a valve very slightly so car gets new timing chain but the valve wear or straightness is out,, not very common as most stop running at this point,,
before anything is done a good level of diagnostics needs to be done, also after fitting a timing chain the cat needs to be checked as dose the upstream 02 sensor as to much overlap on valves due to stretch chain causes unburnt fuel to destroy both items.. as after fitting chain kit and or cat the car must have its adaptations reset,, this resets the ecu back to new state or learning ,, autocom cdp+ or b-cables inpa full bmw diagnostics platforms are good for this,, i like the autocom one more as it does all cars 55000 + will do airbags abs body control stuff prettymuch everything