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New 400cc Injectors Running Extremely Rich

Posted: Tue Mar 09, 2021 9:46 am
by jc_sg
Dear experts,

I have just upgraded my injectors due to the one of the original stock injectors not firing correctly.

In the Fuel table, I have updated the injector size and injector opening times based on the spec sheet, but the car still runs extremely rich. i.e. fuel trims are way off and the car is spewing black smoke.
The spec sheet provides the size, a pressure, which I'm guessing is the "injector test pressure", and some numbers corresponding to voltages which I'm guessing is the injector opening time.

May I know, what am I missing here?

Any inputs would be very much appreciated.

jc

Re: New 400cc Injectors Running Extremely Rich

Posted: Tue Mar 09, 2021 9:59 am
by Spunkster
Are you running the same pressure that they were tested at?

Re: New 400cc Injectors Running Extremely Rich

Posted: Tue Mar 09, 2021 10:15 am
by jc_sg
Yes. The pressure number indicated on the spec sheet is 43.5 psi as per the original in the Group N calibration for the FN2R.

Re: New 400cc Injectors Running Extremely Rich

Posted: Tue Mar 09, 2021 11:24 am
by Spunkster
You will have to make adjustments to the fuel table to get it to the correct AF ratio.

Re: New 400cc Injectors Running Extremely Rich

Posted: Tue Apr 13, 2021 5:42 am
by jc_sg
I managed to get the original injectors serviced and plugged them back in. However, strangely, the fuel trims look like they are the same with the upsized injectors! :(

It's telling me to richen up the idle portion, up to 25% and at 2V+, it's telling me to lean out by 15%... Things are looking strange.

Re: New 400cc Injectors Running Extremely Rich

Posted: Tue Apr 13, 2021 9:59 am
by Spunkster
Have you discussed this issue with your tuner?

Re: New 400cc Injectors Running Extremely Rich

Posted: Tue Apr 13, 2021 10:26 am
by jc_sg
No, not yet.

But I'm not sure if it is a tuning issue or a hardware issue as the map is a base GroupN map.

Re: New 400cc Injectors Running Extremely Rich

Posted: Tue Apr 13, 2021 11:21 am
by Spunkster
This is definitely something you should discuss with your tuner.