3.5 TMAP reading are off (+/- 5psi) on JB4

[oVeRdOsE]

I saw only 1 single post on that, and no solution.

- inb4 '' get rid of jb4'', yeah , but not yet. Work fine for my needs.

Spec : N54 , ST, MHD BEF, Maps on JB4 G5 (lasted ST firmware), 3.5 Continental TMAP N20 w/ wiring reversed order , BMS 600CC meth kit.​

Issue : Ive noticed 48°F iat @ 27psi on a 5.5'' stepped IC. Quite low !

I've added a external boost gauge and BINGO ; it read 22 psi, while JB4 read 28psi (peak) !


reached Terry, he doesn't know.

He told me to put TMAP :
- Setting to 1 : No , I ve a check engine and a 7.8psi readin on IDLE !
- setting 2 : same behaviour
- Setting to 3 : bingo, idle reads 0psi ( or vacuum) , but Ive a +/- 5 psi offset


ONLY 1 person reported Setting 3 did the trick, but he never validate the REAL boost pressure !

Any way to ''calibrate'' it?



here Setting 1 at idle :

 

[oVeRdOsE]

getting worst by doing nothing?


get the car out of storage, it runs fine, feels like around 480whp.


The ONLY thing Ive changed is the MHD update for MHD+ and merge all MHD app version. So it aksed me to reflash the BEF.


But log 45 psi !!!!!!!!!!!!! (no way on 94 fuel pump lol) by chance my external gauge shows 22-23ish psi.
Also HPFP crash and kick me back in map 1

datazap map 3 94oct meth

 

[carabuser]

I'd love to assist, but I don't know where to start with a JB4.

The N54tech forums were always the place to discuss the in-depth calibration for a JB4. I did used to read them sometimes as they offered a less toxic board than bummerboost. I wouldn't rule out component failure on the board though, the few times I have seen strange issues on JB4 cars the have needed board replacements.

 

[oVeRdOsE]

thanks, I saw you're pretty active in the N54 platform, Ill let you know if I change from jb4 to full mhd.

So far the car runs great, ive double checked with virtualdyno, 23psi or 45psi, it read the same whp.

can't explain why the board would have failed stored few months on a battery tender in a heated garage.