Engine:
S4 T2 block with S5 NA rotors, engine is naturally aspirated.
ID 1000cc primary injectors and denso 460cc secondary injectors.
AEM uego wideband gauge, and egt sensors for logging.
Running on a Power FC with banzai harness and datalogit.

Was trying to use only ID1000 as primarys and run without secondarys, but when i did that the engine died at 50C every time, put in the 460cc injectors as sec injectors and that solved that problem. Drove the car around and it seemed to work fine, did not do a pull thru the rev trange on the road, but i did rev it up to 7000 when the car was sitting still, and it went all the way up smooth, without any stuttering/hesitation.

First time i noticed it was yesterday, did a pull in 2nd gear without stuttering, then i changed gear into 3 and started doing a pull, at around 5000rpm it started to stutter/hesitate and i just backed off the throttle.

Did some more pulls later on the day, wich i logged. Seems to me like it happens under load, i think the only reason it did not happen in 2nd gear earlier on the day was that it was a slight downhill where i did the pull.

Here is the log from datalogit:
File Manager - One.com

File Manager - One.com



sec transition is set at 50% now, and it seems to reach 50 just around where the issues appear, so might be a sec transition problem, will try to move the sec transition up and down later today, to see if that solves or moves the rpm at wich it starts to stutter/hesitate.

 

Too rich or misfire are the normal reasons.

 

Have you looked at the log? AF doesn't seem to bad from what i

What should i check?

Got an answer from the yahoo pfc group, and i was told that it could be an ignition issue.
So i changed plugs, and i still have the same issue.

What else could be the reason for ignition breakup?

 

Changed 460 to primary and 1000 to sec. Did not change anything.

Looked at everything, and since everyone seems to think my map seems fine i thought that some settings where bad. After thinking about it, and trying do add/pull fuel and ignition, and nothing realy changed anything.
So i started fresh from the base map Banzai racing supplied me, and made some changes according to your fc specific tuning notes. And i stumbled across some talk around "dwell vs rpm" , on the base map i was supplied it was set to 30 at all rpm's both leading and trailing, i changed it to what i believe is the stock settings ( 9, 17, 34, 70, 108, 123 for leading and similar for trailing), did two pulls, one to 6500 and one to 7000rpm in third, without the slightest hesitation, changed the dwell vs rpm back to 30 for all, and then the hesitation returned.

And to explain what i think is the reason for this to be an issue for me, while others run banzai base map's without issues:

I use an FD igniter with the FC coils, wich would mean i need the FD settings, while others may be running modified FC ignitors, and 30 might work with that. Feel free to confirm or correct this statement!