I need some help. Here is a nitrous run I made.
I have put the vertical line at 4000 rpms which is exactly when a 100 hp shot of nitrous and fuel (wet shot) was injected after the MAF sensor but before the throttle body. The nitrous turns off at 6200 rpms. Note the following.
1. The injector pulse widths immediatly drop from around 21 to 17.5. They stay there for about 1 second then they climb back to near 20. They never return to 21 and even drop off again above 6000 rpms.
2. When the injectors drop off, the AFR jumps from 12.6 to 15.8 (bottom section of chart).
3. The fuel pressure drops only a very little (bottom section of chart).
4. MAP stays constant at or above 100 kPa.
5. MAF has a slight drop but only after the injectors drop (probably because of reduced air flow with less fuel).
6. Spark does nothing strange.
Why are the injector pulse widths droping?
My first thought was fuel pressure. It might be. I am using the stock fuel pump (I have ordered a booster pump). Would reduced fuel pressure cause the injector pulse width to drop?
The MAF does not see the nitrous because it is injected after the MAF. The MAP can not tell since it is maxed out before the nitrous is injected. Are there any other sensors that might be seeing the nitrous that would tell the injectors to reduce?
It is a manual. Could torque managment have any effect?
A few of us have been racking our brains on this one. Any help would be appreciated.
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