I have a problem with my LET Engine, seems to be running lean by the look of the Spark Plugs, the problem i have is if i run anything more then 10psi, regarless of chip or not at high revs after 4000rpm it starts mising and sounds like its blowing the spark out abit.
I have changed, Plugs for Denso ones, Leads, Coil, Dizzy, Got and cossie fuel reg adjustable. uprated accuator. injectors off my m8s LET which runs fine.
Only thing i aint changed is fuel pump, had a fuel pressure gauge on it while driving, it reads 3bar on idle, then 4 when u start booting it then it drops to about 3.5bar when u get to about 4000+ revs.
i have tried for ages to sort this problem and now its getting me abit p1ssed,