Engine Cut Problem in JZZ30

[sil80 1J]

Can someone shed some light on where to look for a solution to my problem?
Im getting an engine cut with the engine light coming on the dash at 5600 rpm and 1 bar boost. It only happens at WOT on cooler nights which leads me to believe its a boost issue but if you nurse the car to redline you can achieve it with 1.2 bar boost. Does anyone know what boost level the computer cuts at? Im running a fuel cut defender and AFR's sit around 11.5 so im assuming fuel is not an issue.
Thanks for any info!!

[pandaah]

have you got an aftermarket map sensor?.. maybe the map sensor cant cope with that amount of load?

[sil80 1J]

no its factory... but it has handled more boost, just seems to be under WOT, i can get more boost out of it if i nurse it up to high revs... any other ideas?

[midnight_purple_GA70]

sounds like boost cut to me...
factory boost cut is supposed to be at 1bar of boost...
you will probably find that under WOT boost will spike quickly and trigger the boost cut...

[Officer Doofy]

Bit of info on the setup would help, standard ecu? What sort of fcd are you using?

First thing would be to pull the code and see if its an overboost warning.

My bet would be that you fcd is set to close to the ecus cut voltage. It would explain why you can get 1.2 bar with less throttle but with wot you are getting a spike over the fuel cut voltage.

Try lowering the cut voltage to around 4.2v if you can.

[HAVABEER]

boost cut and fuel cut on the stock ECU is at 14psi

[hamgatan]

yeah my moneys on boost cut as well. my AVC-R always used to indicate around 1.02bar on logging mode every time i hit cut.. your FCD's probably fubar/not wired properly.

[sil80 1J]

thanks for the info dudes! i thought it cut at 1 bar but wasnt sure, ill pull up the carpet and have a look at the FCD. is there any way of getting the fault code without a diagnostic computer? can you put the car into diagnostic mode like a nissan?
cheers

[midnight_purple_GA70]

bridge terminals T1 and TE1 in the engine bay diagnostics port...

turn key to on...

watch and wait on your scroll bar... should come up with things like
EFI OK or EFI NG
NG = not good

if anything comes up as NG wait longer and it will go into detail and give you error codes...
you might have to press the "scroll" button on your dash to switch from EFI to the next error code listing...

cant recall its been a while

[sil80 1J]

ill give that a go, thanks again for the info!