Welcome to the SR20 Community Forum - The Dash.
Register
SR20 forum logo

Thread: Part throttle lean condition

+ Reply To Thread
Posts: 1-8 of 8
2010-06-17 01:46:20
#1
Part throttle lean condition
Anyone have this issue when running blow-thru? I have a lean issue when about 1/2 throttle while in boost. Obviously I don't wanna run lean, but I figured I would ask other people if they have had this issue?

My plugs came out with white ground straps the other day, and I don't wanna continue driving it like that. My AFR on the dyno during WOT are perfect.

I know that some people have tried changing maf position or rotating it to get different readings. Anyone care to elaborate on their experiences?
2010-06-17 02:04:45
#2
I never had any issues running blow-thu. Used Z32 MAF ~18" from TB with 3" tubing from maf to TB so there were no size transitions.

Calum realtime ecu with tune by me.
2010-06-17 02:05:59
#3
Pics or details of how you have your maf?
2010-06-17 04:31:39
#4


You can see the maf is only about 8" away, if that. There is a size transition as well, so this is far from ideal. I am just trying to see if I should just spend the money and go Air/Water now.
2010-06-17 04:46:43
#5
Not a tuning issue ?
2010-06-17 04:47:53
#6
I don't think so. The timing map for the JWT VE program is a little different, but the fuel map for this should be the same as any other JWT Z32 with 740cc inj.

What is interesting, the SR computer uses the maf to determine fuel and timing requirements, so any increase to the MAF voltage will cause an increase in fuel delivery. I don't think the TPS is even used for fuel delivery. The TPS was adjusted a while ago and everything checked out fine, but I do have another in case. I just don't think it would be a TPS issue.
2010-06-17 20:57:55
#7
Yeah I don't think it is tuning (MAF voltage for airflow is unchanged based on location, assuming everything is ok). I would suspect issue is MAF being too close and it is getting some hysteresis in signal from TB airflow disruption. I don't think the transition to 2.5" helps either.
2010-06-18 00:34:41
#8
I raised fuel pressure by a couple psi, and retarded timing by 1*. Running 15psi (equiv to 12psi at sea level) and the car is running ok. You feel the slight loss of power, but it is still making 350whp.

I cleaned out the maf and rotated it 90* to see if that helps things.
+ Reply To Thread
  • [Type to search users.]
  • Quick Reply
    Thread Information
    There are currently ? users browsing this thread. (? members & ? guests)
    StubUserName

    Back to top