View Full Version : Hi boost causing missfire

31-03-15, 14:03
Looking for all the reasons this could happen and could it be down to
stock valve springs not being up to the job ?

This is on a SEAT K1

Below 18 psi it appears to be fine, above it gets the missfire

David P
31-03-15, 14:29
Try smaller plug gaps.

31-03-15, 14:52
Whats the fuelling like, I would be looking at this along with plug heat range and gap.

12-05-15, 15:05
Sorry for the late reply

It would appear to be the coil packs weren't up to the job, a new set has been fitted
and the missfire has gone

Chris Wilson
12-05-15, 15:49
You can tell on a rolling road if the boost is unseating the valves as the HC's will REALLY go to hell, and you usually get a rapid, cyclical boost, as it recovers again, then holds the valves open again. In your case CDI is your friend :)

12-05-15, 17:29