Nistune Forums

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

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

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...

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