Hondata

No matter how I tune, my afr fluctuates 10 to 17
when i tune the idle at 14.7 and rev to 3500-850, the afr in the idle goes back to 10 and then it goes up to 17 and then down to 14.7 and so on.

then when drive with first gear and rev the car up to 2000, the engine begins to stutter at over 2000 the afr is going down to 10. no matter i tune i cant fix the problem.

First we thougt that my Ecu ist damaged and i boght a new p28 and socket it. But the problem don't solved. Then i have bougt new injectors (rc650) but its the same problem -.-

After i have entered other injectors dead time and my car runs fine for the first miles but after a few miles the stutter started again and at some point during the ride, it went away again.

although we tuned the car in the idle at 14.7, the afr varies from 10 to 15.

I hope someone had this problem to and can give me tips.


My engine:
d16y8
rc 650cc
hondata 4 bar map sensor
aem boost solenoid
hondata s300
honda crx del sol 1996 (obd2)
kkk k04 turbo
p28 ecu
walbro intank fuel pump

please help mee my car is since january in the garage :(

When i plug in my oem p28 G03 Ecu with oem 240cc injectors and oem map sensor, car will drive without stutter or something like that.

Thank you very much.

Hi Spunkster,

here my datalog and map.

d16y8
rc 650cc
fuel pressure @ 3 bar
hondata 4 bar map sensor
aem boost solenoid
hondata s300
honda crx del sol 1996 (obd2)
kkk k04 turbo
p28 g01
walbro 255 fuel pump
obd2a to obd1 connector

The problem is, its not matter what i do my car stutter over 2000rpm. but when i rev the car in neutral, there is no stutter.

My tuner and i cant find the problem. There is a little problem. We changed my ecu and injectors without success.

Then decreased the injector open time over 2000rpm so that the estimated change in fuel to reach target lambda says +15 and the car stutter and stutter.

Do you have any ideas?

i have forget to say.

We have input other death time values for the injectors and then the car runs fine no stutter. And then after 20 kilometres and reving over 5000rpm the stutter began again. This is the reason why i say that my tune is not the problem.

Please help me.

From Help, About, what version of software are you using?

i've find the problem.. my obd2a to obd1 connector was the problem.. now it runs fine and i hope the problem will not come again..

thank you spunkster for your help :)