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Hello all,
I've got a 2004 MCS, R53. I had a misfire on Cylinder 3 and went down the diagnosis road. Cylinder 3 is not pulsing
Good spark, Replaced wires, plugs, coil
Replaced all injectors, All "ticking" except cylinder 3, put all new injectors in, now all ticking except cy3
Testing the wiring harness I don't see any issues yet with signal, But a little unsure I'm testing this correctly
Any hints? Do I need a new ECU? I haven't done a compression test yet, but wouldn't the injector be firing regardless of compression? Could this be a grounding issue?
It is possible that the ECU driver from injector 3 is defective,in this case you must replace ECU.You have two alternatives,buy a kit used ECU , keyfob,EWS,or BUY an immo off ECU.If you buy an immo off ECU, i advice you to buy a MS5150 ECU, not THE old EMS200, because MS5150 it is much more reliable than old EMS2000.
Looks like the non-pulsing injector was caused by the computer recognizing that cylinder 3 had no compression. I did a compression test and got zero. Double checked my timing just to be sure first and then took the head off. And, well.... A picture tells a thousand words. Exhaust valve on cylinder 3 is blown. Parts are now ordered and I'll dig into it soon. BTW, its hard to find reasonably priced valves for an R53. I got mine from pelican parts.
