Every time i hit 5400rpm or higher at any load (half throttle boost and no boost) it hesitates and the knock goes to 100 plus so i back off,this has only started happening all of a sudden as no changes have been made to the car that would effect it.It always starts to flash at 5400rpm though no matter what im driving like,any suggestions would be great,thanks Roy uk.

Mods on car are-intake
downpipe
midpipe
blitz catback
mild port
frount mount
1200cc sec injectors
cosmo 20b pump
The only thing i can think of is maybe the 1200cc inj are not working correctly.

 

First check your RPM fuel cutoff value (max revs).
Maybe it got set down to 5400.

Next check and maybe lower the transistion rpm for when the secondary injectors come on.

 

I haven't got datalogit so im not sure how to do this,can it be done with the commander.Thanks for the help.

 

My car has been doing something similar w/1300cc injectors @~4000rpm. I am convinced it is the secondary overlap settings, but nobody has a Datalogit in stock to order so I can fix it!

Check out this thread:
https://www.rx7club.com/forum/showth...hlight=stumble