My MX5 based kitcar has developed an intermittent problem when driving at speed. The car is running a MSPNP and has only just developed this issue.

When i'm approaching speeds of around 85-90 (on track days) everything seems to die and loss of RPM, loss of Sync with MS. I was assuming this was a complete loss of power maybe due to alternator or even a coilpack issue. When this happens i can just turn off key and turn back on and its back to life.

I noticed yesterday when it did it that after the cut out it started kicking out smoke (unburnt fuel) until i turned key off and on, then it stopped smoking and the car ran perfectly normal.

After speaking to skuzzle last week i spent most of the weekend trying to simulate it by pulling and knocking fuses/wires to eliminate a dodgy connection but nothing would until car was travelling at speed then it happened. Replaced battery earth lead today just incase.

I was wondering if anybody has any thoughts on this?

Cheers

 

What year are the coils from. There have been several different types used over the years. Some are better then others, none of them are considered "great".

 

It's a 1994 Mk1.