1st Gen R50 Cooper Most liked posts in thread: Urgent help needed!

I did a test last night. Same as before. The engine runs fine although a little rich with the Tmap plug off, also I tried the plug on the new Tmap with the old Tmap in place. The engine runs really rough and very rich but no misfire. The Tmap somehow sends some message to the ECU sensing the misfire.

I even tried plugging in the other 02 sensor but not fitted to see what happens. Same issue.

I can do the reset tonight.

At this point I've thrown enough money at this problem to buy another used Mini R50!

 

ah yes, the experience is..........buy a Subaru rally car next time LOL

Anyway I thought maybe the crappy fuel gummed up the cylinders. Does Seafoam work?

Sea Foam Sales Company

 

The point of this thread is get advice and help others who might encounter this problem.

I've posted all the things I've done, good or bad . Electronics are not my thing so maybe that's the issue but swapping parts/sensors has not resulted in a solution. Even the dealer could not figure it out hooked up to their BMW computer for 2 weeks.

 

I'm doing that right now. There is an Ex BMW dude here who works for himself fixing BMW's I emailed me to tell me he has this issue with BMW's all the time. Some hope there I think.

 

Here's the latest:the BMW tech says it is the knock sensor picking up a vibration, maybe but I tried running the engine with the knock sensor plug off. Same issue

 

Thanks chaps! I did post the problem on Mini Torque and some guy suggests the ECU is now getting enough volts, so I'll be checking that.

 

So I sit here thinking what else can I do? I did the compression check again, after several cranking I get around 210 psi on all cylinders. So I did a crank over by hand which might now prove much. Anyway I got 28Psi on #1 and about 15psi on #2,3,4

 

yes I thought that, time to revisit the fuel filter.

 

Well I think the Might of Total would squash any of my attempts to make a claim.

No rain last night and I felt frisky! So I pulled out the injectors, inspected/cleaned them. Nothing strange. The I took off both sets of valve rockers to see if the cam is worn, all looked good. So I a valve tap test with the pistons half way down the block. The idea was to gently tap the top of the valve to see if some have more resistance then others to try to see if I have sticking valves. Not the best test but something is something. Actually some valves had a ping and others a thud so maybe the thud is a tighter valve than the ping???

I put everything back together and tried the mystery 2500-3550rpm. Misfire still there! Oh hum

I suppose to be 100% sure I have to pull the head at some point. The head is from a 25,000 miles Cooper S so should be in good order. I did rebuild the head in 2012 so it has about 4000 miles but most of that is at high RPM.

Anyway the head will have to wait until next year. One good thing is the engine runs the smoothest at idle then it did before.

 

Yes it's looking that way! This Mini is cruel, last night I thought I'd cracked the problem and then "bang" the problem is back.

I do a lot of searches on this issue and some dude down under had a similar problem with his Nissan 300ZX twin Turbo. OMG he had 6 cylinders worth of parts, he went though more then me to find the issue, which was a faulty new 02 sensor!

 

False alarm. I thought the melted power cut off switch was the problem Nope!