After intake install the car not running right.

Ari nismo87 at houston.rr.com
Sun Nov 14 13:32:03 CST 2004


Something is definitly wrong with my car.  The problem is that according to
my wideband o2 I'm getting a 13.8-14.3 A/F at WOT.  Here is how my A/F curve
looks NA and with a 50 shot
http://gallery.thevboard.com/showpic.php?dispsize=Original&album=Nismo87se&pic=se-r%20dyno%20(small).JPG .
Since then I had to unplug the battery to change my CAI from these
http://gallery.thevboard.com/showpic.php?dispsize=Original&album=Nismo87se&pic=sercai.jpg

http://gallery.thevboard.com/showpic.php?dispsize=Original&album=Nismo87se&pic=sercai2.jpg
http://gallery.thevboard.com/showpic.php?dispsize=Original&album=Nismo87se&pic=sercai3.jpg
to a full 3in piping.  Now my A/F is leaned out by 0.7 A/F all the way
across.

I verified that my o2 sensor is working properly (I had an extra bung
installed for my wideband), the maf is working perfectly also, I tried
pinching the PCV tube to find an intake leak but that was unsuccessful.  I
did also switch from a pacesetter to a gen VI hotshot header so I'm not sure
if that had any affect on the A/F ( the PS did run richer).  With my nismo
FPR I tried adjusting the FP but that ultimately didn't change the A/F much
at all.  I tried going from 36psi at idle to 44psi and my A/F curve was
still the same but maybe 0.3 A/F richer overall.  With my techtom I did
notice that my injector msec did drop as did my A/F ratio alpha.  Basically
my JWT ecu (S3/S4 with n2o program) has corrected the increase or decrease
in FP to get its target A/F in closed loop and I guess applies that to open
loop, thus I run lean.

I do have some measurements I took from my techtom during some WOT runs.  I
get a peak of 4.54-55v from the maf @ 7400rpm (was 4.59-61v with old intake)
o2 sensor shows 0.85-86v, injectors reached 13.0msec peak, fuel pressure was
43psi @ 19in/hg and 50psi at 0in/hg Also if anyone is near houston, TX that
has anything that could datalog from the consult port please let me know.
I'm thinking that with a datalog I could see my duty cycle and compare it
with the maf + o2 voltage.


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