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

Good point Crashton but I changed the battery this year. I have been thinking the roll could have cause some wiring issues......let's hope the battery is at fault.

 

Last night I pulled the cam cover off, checked the cam(not broken), changed the cam followers/arms for another set and tired again. Still the same fault so I put back the original followers.

I took off the intake, all looked good but I did notice #3 and #4 wet with fuel. I put everything back tried again checking the misfire detection values. 0 for all cylinders until around 2000rpm where #3 starts logging faults and increases to 300 just before 3000rpm. #4 has a value of 5 just before the misfire is detected. Going from 4000rpm and up there no cylinder misfire detection. Reducing down to 3600 #3 increases the value and #4 goes to 5 then #4 is deactivated.

I now have a long list of what the issue is not. Reading back I had multi-cylinder misfire on any of the cylinders except #1. Changing the harmonic balancer, V belt and alternator resulted in only #4 being deactivated. Since the change of the latter this has been the case. #4 is now the only cylinder with the error code.

I've changed: fuel pump, filter, 02 sensors, T-map, crank/camshaft sensor, Knock sensor,injectors, leads, coil pack, plugs, alternator, pulley, V belt, timing chain and engine loom.

Checked: the compression, fuel pressure, valves, cam, cam followers, cat, fuel vacuum leaks.

Removing the plug from the T-map removes the 3 cylinder issue but the popping gets worse at 3000rpm I think removing this plug some how deactivates the misfire detection but what is strange is, if I connect another T-map to the plug leaving the other T-map in the intake the engine runs really bad but does not go to 3 cylinders. Which makes me think intake pressure/load influences the misfire detection.

Seeing as I have moved forward to having just 1 cylinder now deactivating and the misfire range has gone from 1500-3500 to 3000 to 3600. I'm going to run the engine with the V belt off again and maybe even take off the harmonic balancer.

We are close!

 

Last night was very interesting, I did 2 tests:

test 1: Run the engine with the T-Map in the intake and plug another T-map in. The engine runs like crap , runs rich but never runs on 3 cylinders. I got more error codes, some related to the coil pack which is a first. I think the ECU was very confused trying to make the engine run correctly. LOL

Test 2: I took off the V belt and ran the engine for a short while due to over heating. The fault happened just once , then didn't happen again.

Now I'm well confused! either the water pump or tension wheel are causing vibration or the alternator is causing some voltage issue.

Also the T-map could be sensing the wrong intake pressure when running in the intake.

I was thinking to run the tests again tonight and try to figure out what exactly is the culprit.

These are the error codes from running the second T-map out the intake.

 

New sensor and ignition key ordered and should be down here by Thursday if all goes well. Thanks Eminiparts!