Nistune Forums

It might be boost leak

isnt there overboost situation?

Sorry for the time to answer, the CA is Dead...






I think I have too much torque for the stock rod and rod bolt...

I actually build a new bottom end, my head is OK.
I will put forget rod

I will tell you the news

ouch

Hi all !

Sorry for the delay for the news but I had a lot of work to have the s13 finished for the last Week End because It was the DriftCup at Anneau du Rhin (France)

The new engine :








I took the opportunity to change my fuel injector to 1600cc, the 680cc ones was too small...

The engine was running a week before the driftcup, therefore I had to break/run it for 400km.
The engine run good, I have mapped it approximatively for the Driftcup at 1 bar but I have to fix the actuator setup to run at the good pressure...

I have a question :
When I'm at very low load (under 0 bar) at 4000rpm I have fuel cut I think... I had enrich the map a lot in this part of the map but I have always the same problem...
The problem doesn't come at higher load.

You can see the movie to describe my problem :

https://www.youtube.com/watch?v=ej-QUIV ... e=youtu.be

Pictures of this WE :







Now I will try to setup correctly the wastegate to have 1.4b and map the car correctly...

I will tell you the news !

Would need logs and tune to see your fuel cut

Hi !

Her you can see the log of the Problem, and the log of today after some tuning on the wastegate, approx 1.1b for the moment.
You can see the last version of the map.
It was not this map when I log my problem but I have allways the problem with this map...

On the today log, you can see that I run a little lean at approx 4300-5000rpm, I have allready modified this on the last version of the map (not tested yet)

Other thing, I need to enrich a lot on the top rpm, is this normal ?

Thanks !

PS: I have add 5° on the timing map, do you think it will be better ?

Flavius424 wrote: I have a question :
When I'm at very low load (under 0 bar) at 4000rpm I have fuel cut I think... I had enrich the map a lot in this part of the map but I have always the same problem...
The problem doesn't come at higher load.

My friend's s13 got this issue too. It leans out a little, exactly at 4000 rpm.
Don't know how to fix this, only solution is to add fuel just a little above 4000 rpm.

What I am seeing form the log is nice increase in RPM and TP

Following this the injection time follows the fuel map, showing an increase (green) but at the same time your AFRs are decreasing from 1:02 onwards. At this point I see the injection time halve, which may be the switch from sequential to batch fire. But as your injection time starts increasing, the AFRs are still going leaner... How is your fuel pressure here?

this is interesting, as I have similar issue too, occasional "fuel cut" at about 4000rpm, at various loads, but allways at the same rpm area, I also think thats its area of seq.-batch injection switch...Until now I didnt log it, but experienced it several times, it really looks like complete cut for a second....

Check if it is when the batch / sequential change occurs. I've heard of it before with CA18s with very large injectors. There is a period during the changeover that seems to affect the ECU (injection time drops in half exactly). Only way I can think of so far to work around it is adding more fuel in the area where the switchover occours or reduce the size of the injectors to minimise the effects

It may be possible to move the switchover point (which from memory is determined by total injection time) by changing time amount

Thanks for your response !

Yes, I think too it's when the ecu switch to batch fire...
My fuel pressure gauge is on the engine buy, so difficult to see the pressure at this time But I see no reason to haven't the correct fuel pressure at this moment (044 fuel pump)

There a no possiblity to rest in sequential or batch fire all the time ?
Does it mean that the stock ECU is not able to manage injectors as big ?

Hi !

Today I have still mapped the engine, and I have solved the 4000rpm problem by putting 10 AFR on the map at the moment of fuel cup. It insn't nice on the map but it works^^

I have adjusted the wastegate to have 1.4b on 3st and 4st gear, hitting 4.42v on the AFM

I have started to play with timing but it's very difficult for me to see a difference between differents timing map (adding 5° all on the map, or just on the full boost part or remove 5° on the charging part...)

But the engine work fine, for the moment I let the map like this...

I put the last log her

Thanks for the log. I'll look into the CA18DET once I finish with the other investigations I'm doing at the moment for the SR20s and see if we can adjust the sequential/batch triggering. If there is code changes I'll include with feature pack updates for that ECU

Thanks for your implication ! And good luck