Mercedes-Benz Forum banner

long term fuel trim % with fuel pressure reg from pulley kit

2K views 5 replies 3 participants last post by  Bazzle 
#1 ·
anyone have an OBD2 scan tool (look at live data if your tool supports it) to have a look at there long term fuel trim on a pullied car? curious to know...

the 4psi fuel reg i think is making it run quite rich across the range robbing power. i do realise this is prob needed top end. (i will find out on dyno this weekend).

my long term fuel trim is -8% now and it looks like its settled to that. the ecu is leaning out the mixture and doing a fair bit of correction because its rich. before removing restrictions in the intake it sat -4.6% still bit rich...

depending on the outcome on the dyno this week i was thinking popping the stock 3.7psi one on and getting a piggyback ecu to tune it. this will prob squeeze out a tad more power of my setup.

i think the 4psi reg works fine on a stock airbox/stock setup because partly it was desgined for that. altitude from sea level plays a part... look -8% correction wont end the world but idealy you dont want the ecu correcting +-10%...... from factory air/fuel map.

currious to see what others are getting?
 
See less See more
#3 · (Edited)
4psi? is'nt 4 bar? :) well, looking forward to your dyno. I dont care anymore to publich picturs or stuff like that(like my heavy modified blower that will feed the air needed) because no one cares, it's just headlight, grill and spark plug that's the hot stuff here....

btw, what scan tool do you use? and good luck with the piggy back ecu :)
 
#4 ·
yes sorry i meant 4bar not psi... i just use a U381 OBDII/EOBDII Scanner. not a bad unit... yeh this saturday they have a dyno challenge who knows ill may win the 4cyl class. but im not there for that just to see power and air/fuel ratios...
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top