Right my race car has developed a nasty missfire.

I melted a piston racing at Knockhill a month back. I think the engine killer that time was the fact that the boost control solenoid on the supercharger had a split diaphragm.

The science in my head is this valve is meant to actuate when dangerous amounts of boost build up and a split diaphragm just means that the valve stays shut and that I forced massive amounts of compressed air into the cylinder head. Melted piston 

Does that sound realistic to you guys as I'm learning as I go with all this!

We replaced solenoid and the problem improved dramatically but there is still a misfire when I hit the very very top end of the rev range….

Here’s a vid where you can hear the fault occur. Another team who were aware of our issue witnessed this misfire from the pitwall and reported a massive flame pouring from the exhaust during the misfire.

http://www.youtube.com/user/jimmyjamjer ... _3SJPUdhH0

We’ve replaced – fuel pump, fuel rail (with pressure regulator), injector, coil packs, plugs. We’ve done numerous compression tests (all good), but the fault remains....

We are replacing the loom and crank sensor this weekend. We are also planning in upgraded valve springs and new hydraulic lifters (solid if we can find any for a Z22SE).

Any further suggestions…?

Do we know of any manufacturors that make solid lifters for the Z22SE?

Cheers

Jimmy