[S15 SR20DET]Very difficult Starting

[Isofouet]

Hi,

I have a starting issue with my S15.
It's very hard to start, cold or warm. I have to crank durng a long time, and open the throttle a little bit during the cranking to make it start.

My mods are :
- Z32 AFM
- Nismo 740 cc
- Tomei M7960 turbo
- Tomei 260 cams

When the car is started, it runs quite good. The AFR are ok (I have a wideband), throttle response is good, closed loop is working.
When driving, I just have a problem with the idle on deceleration : I stall when I release the throttle. But, if I manage to keep the engine alive, it idles right.

I tried basically to put a base map, change the injectors and AFM, and of course tick the boxes "adjust cranking tables"
When it has started, I set the K constant, this is OK... but I still have difficulties to start. Here is a video :

https://drive.google.com/file/d/0B_F4FH ... sp=sharing

I assumed there were to much fuel, as I have to throttle and as I find fuel on the plugs after a failed attempt.
I tried to remove fuel from the crank enrich table, but it was worse.
I tried to change the engine cranking pulse offset. It was a bit better by adding fuel, that's weird...

Here is my test map :
https://drive.google.com/file/d/0B_F4FH ... sp=sharing
The fuel map is not the good one, it was a specific map for cranking tests

I looked at the injectors. They don't leak. The spray seems to be quite important, but I don't really know if it's normal or not.

The spark plugs are not very nice, but not completly dark. The sparks occurs, I checked the 4 of them :
https://drive.google.com/file/d/0B_F4FH ... sp=sharing
The starting was a bit better when I cleaned the tips of the plugs with fine sand paper.
I will change them anyway.

Right now, I'm out of ideas... I'll try to put back the oem injectors and AFM... we'll see...

Thank you

[Matt]

You need to reduce the fueling in your cranking tables. It appears you only adjusted injector size used after cranking

More info in this guide here:
http://www.nistune.com/docs/Workshop%20 ... %20Web.pdf

[Isofouet]

Thanks for your answer,

I tried to remove fuel from the cranking tables, but it changes nothing, the engine ends to be drown of fuel...

I have to check other things (grounds, compression, etc), because I could start way easier before...

[Fast Guy]

Is number 3 firing as well as the others? It doesn't stand out too well in that video.