My car has a really strange and irritating misfire. It starts when the car is fully warmed up and the miss isn't constant. It will miss about once every 15 seconds and some times a couple of times in succession. This is most noticeable when the car is at idle, But I can some times feel it when the car is running on constant throttle. I have plugged my timing light up to each of my ignition leads and found that when the car misfires I would get a gap in the firing pattern on the cylinder I was checking, a bit like this +-+-+-+---+-+-+-+ this was most prevalent on the second cylinder up from the front of the engine. So today I went and brought a new set of ignition leads hoping that would solve the problem. I then took the car for a test drive and the car ran without the misfire. Until I pulled back on the drive and it started again! I'm not a very happy person after spending £90 on a set of leads, but then again they where old and had started to fall a part. I have read about other people having misfires with there m103 and m104 engines, but most seem to be fuel related and more extreme than the one I'm currently getting.
I did find a spare EZL unit in the boot of the car just after I brought it. Which is a tad worrying. The one I found in the boot was a Bosch and the one on the car is a Siemans and they look slightly different. So I’m taking a guess that the Bosch one didn’t come off the car.
Also the car has a very small flat spot at 5000rpm and then doesn't seem to accelerate as I would expect. Am I right in thinking the car has variable valve timing? As there is a inlet camshaft adjustment solenoid on the front of the engine. The wires running to it look like there past the best and some of the sheath has melted away. So could this not be working proply?
The car was also hooked up to a Mercedes diagnostic machine a couple of weeks ago and no fault codes where found.
Is there anyone out there who could shed some light on my irritating misfire as it's really getting to me.
I did find a spare EZL unit in the boot of the car just after I brought it. Which is a tad worrying. The one I found in the boot was a Bosch and the one on the car is a Siemans and they look slightly different. So I’m taking a guess that the Bosch one didn’t come off the car.
Also the car has a very small flat spot at 5000rpm and then doesn't seem to accelerate as I would expect. Am I right in thinking the car has variable valve timing? As there is a inlet camshaft adjustment solenoid on the front of the engine. The wires running to it look like there past the best and some of the sheath has melted away. So could this not be working proply?
The car was also hooked up to a Mercedes diagnostic machine a couple of weeks ago and no fault codes where found.
Is there anyone out there who could shed some light on my irritating misfire as it's really getting to me.
