Autosport Labs

Hello all,

I've had a MJ4 fitted to my Midas kit car for nearly two years now, until the last few weeks everything has worked beautifully. Recently though I've been getting a slight mis fire when the car is warm and as time has gone on it's gradually become worse to the point where it feels to be running on two or three cylinders for the bulk of the time.

So far I've replaced the plugs, the leads and the coil pack. The compressions are good and pretty much equal across all four cylinders, if anything the mis fire is now worse.

I've taken the EDIS unit off to have a look at it and found some corrosion on some of the pins.

Do any of these symptoms sound familiar to anyone?

Scrub that I've fixed it.

It had started sounding so much like a failed head gasket between 2&3 that I was going to do the gasket despite the pressures being good.

The cause of the mis fire was in fact a failed joint on the coil plug which was intermittently cutting two cylinders, now fixed and running like a dream again!

Good you found it- was it a bad joint on the HV ignition wire, or the coil pack connector?