After some days of cruising around the car is hard to start.
After changing plugs the car is ok again.

No boost have been usen lately due to problems with boost controll. ( That issue is fixed now)

A/F is 14-15 on cruise.

What can the reson be that the plugs are fouling. ( using NKG race plugs. )

 

Can you explain your setup and mods more? What turbo are you running, what boost, and what computer do you have for your engine?

And do you really need those plugs? I stopped using aftermarket plugs and went back to BUR9EQ's. A lot of those race plugs either foul out or otherwise have a very short life. They're also really expensive and I think their benefit is unproven for most normal street setups. Also certain aftermarket plugs can't take sustained high exhaust temperatures and will crack/fail.

 

550/1600 injectors
GT35R turbo
FMIC
Power FC
Also FD manifoil / TPS / AIT
Car will run on 1 bar after trip on dyno next week

Been using BUR9EQ's braking in the engine.
Changed over to race plugs first time on dyno.

Problem was also there with the BUR9EQ's.

 

It might be cruising with race plugs. You might try hotter plugs for your normal driving, and then go back to the race plugs only for track day. See this discussion of the advantages and disadvantages of hot and cold plugs from Mazdatrix...

http://www.mazdatrix.com/ign-2.htm

 

Been runing race plugs on my FD 2 years now, and had no problem.
It seems just wired that they should foul out that fast on the FC.

got me thinking if something is wrong with coils or igniters.

 

Do you have a Datalogit? Post your map. If you had the problem with the BUR9EQ's it makes me think there is a tuning issue. I run 16psi with the BUR9EQ's on a T04R turbo (larger than GT35) with no problems.

Does the car ever flood? What are AFR's under boost? At idle? During warmup? When you say the plugs are fouled, do they smell like fuel? Could you post good pictures of them?

 

Under idle it is 13-13.2
Warmup aint perfect now, but not an issue i have done anything to yet, due to other issues.
Under boost it is low 11. ( car need retune, due to fixed boost problems )

 

There's no guarantee that this is going to solve the problem, but the crazy AP Engineering timing map you are running can't be helping. The AP Engineering map (which I see has been modified slightly) has very retarded leading timing for a pump gas street ported engine. It also has the leading and trailing plugs firing pretty close together compared to what most people run (not enough trailing split). And you still have the 15 degrees of warm up ignition retard, that's probably not helping either. The AP timing maps are very different from the maps that come in the current model FD PFC.

I went ahead and made a bunch of changes to your timing. I've had luck with this leading map on a stockport s5 with AP Engineering PFC and hybrid turbo as well as on a street ported FD with stock twins. I increased the trailing split significantly, and I turned off the warmup ignition retard. That's mostly to heat up the catalytic converter anyway. This should be a good starting point if you want to continue tuning it.