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New Injectors 740cc problems

Posted: Sun Mar 21, 2021 1:14 am
by Andre Klingauf
Hello everyone :-),

i am from germany and try to explain my problem.
by the way, i use the feature pack 2.0 for my SR20DET with the ECU 23710 / 75F00 (Type 3 Board installed).
Following the instructions, I zeroed the cells in the fuel map to get an AFR of 14.7. The O2 sensor is not connected.
At minimum load, i have now set a value above total injection multiplier of 14.7.
So far so good, when i keep the RPM at idle at 2500, the mixture is very lean 18-20 Afr and the engine starts to stutter.
Similar problem when i give short 2-3 short burst at idle, the mixture becomes very very rich and the engine jerks.
In the manual many of the setting options are not available for me, or i'm too dump to find them :|

Does anyone have an idea and can help me?
Here in Germany there are not many who deal with Nistune grrr...

Re: New Injectors 740cc problems

Posted: Sun Mar 21, 2021 2:26 am
by unex
at first set fuelling at WOT 4th gear. After that adjust injection latency to get good idle afr

Re: New Injectors 740cc problems

Posted: Sun Mar 21, 2021 3:55 am
by Andre Klingauf
So you mean I should give full throttle in 4th gear and then set a mixture of 14.7 via "Total injection Multiplier"?
I have only one injector latency table. (DEATSCHWERKS 740cc) (DW300 Fuel Pump)

Update: I have now driven a few test laps, in 4th gear and between 2500-3800rpm full throttle. I have managed to achieve a value of 14.7 afr. Also quick throttel punches were now successful. Max load (TP) I had to increase. But now I still have the problem when I idle and hold the throttle at 2500rpm, that it will lean at about 18-20.
The fuel table cells were zeroed.

Update2: I was able to solve the problem as good as.
The problem was the injector latency table,
I had to change the value from 0.54ms to 1.10.
After that I adjusted the Total injection Multiplier every time.
Now 90% of the time everything works fine.

Re: New Injectors 740cc problems

Posted: Mon Mar 22, 2021 5:13 pm
by Matt
Glad you got it sorted. We dont normally zero the fuel map

We will resize the injectors, and then put the vehicle into cruise conditions (about 2000rpm and 1/4 into the map on load) and adjust injection multiplier to get near stoich and 0% fuel trims

After that we adjust the fuel maps. From 370CC to 740CC we would end up with about half the original factory values at the top of the fuel map

Re: New Injectors 740cc problems

Posted: Wed Mar 24, 2021 8:16 am
by Andre Klingauf
Thank you,

everything is now running perfectly :)
Fuel map can be set perfectly, as well as the timing map. My phormula ks3 warns me of knock. Ignition a few degrees back. I am so happy :-D

Re: New Injectors 740cc problems

Posted: Wed Mar 31, 2021 4:28 am
by Matt
Great 8)

Re: New Injectors 740cc problems

Posted: Fri Apr 02, 2021 5:57 am
by Andre Klingauf
Hello guys :),

i have a small problem that I noticed later.
When I give short gas shocks, blue smoke comes out of my exhaust. When I drive normally then not.
When I give full throttle or drive normally everything is ok,
as soon as I get off the gas and shift into the next gear, blue cloud ...
sometimes it pops when changing gears in low revs
every now and then it pops when changing gears in low revs.
My engine is new, I can't imagine it's the valve stem seal or something.

Re: New Injectors 740cc problems

Posted: Sun Apr 04, 2021 11:01 pm
by Matt
Can you post the log too? We need that to see the issue

Re: New Injectors 740cc problems

Posted: Mon Apr 12, 2021 12:53 am
by Andre Klingauf
Hey :)

I have had the last tuning so much power that I have lost control.
It was very slippery, and the guardrail I kissed with only 10kmh.
I forgot to record a log file. I now have to repair the Silvia and order a new bodykit.
I will get back to you in time...

Re: New Injectors 740cc problems

Posted: Tue Apr 13, 2021 8:17 am
by Matt
Oh no :shock: