Injection time problem

[kg300zxtt]

I have a ka24de that I'm running a nistune on for a few months without issues.
Now i swapped in a build ka turbo and with a gt3071r and z32 Maf and deatschwerks 810cc injectors.
The issue is that injectors are flooding the engine after the k constant was changed with resizing injectors and resizing maf options, what i notices that changing parameters in nistune has no effect on the injectors. The injection time in nistune goes way up when I'm cranking to max pass 40ms

So my question are the injector drivers bad and do i have to get a ecu.

Also within 5 days of changing and checking and countless attempts to start, it started 2 times for about 8 seconds than flooded.
I also put that ecu on a different stock car and it did the same thing flooded with a stock image.

So I'm confused why would it start if the ecu or injector drivers are bad.

[TM_S13]

have you adjusted injector latency ?

[PL]

They're pretty big injectors. Tuning for stuff like starting, idle and low load operation will become more critical than usual, so I hope this isn't your first tune.

I recently had a car (SR20) with 740cc injectors that needed some adjustments to avoid overfuelling at startup. I did a bit of testing and found that I needed to lower TTPmin in the 0 to 600rpm area and there are also some cranking tables that you can adjust. My main problem was that TTPmin was too high but I still haven't done exhaustive testing, so I don't know if I fixed it (not my car, so I have limited opportunities to work on it).

I'd suggest removing plugs to injectors and removing spark plugs, then crank the engine and monitor the injector pulsewidth. Modify values in the TTPmin and Cranking tables to get your pulsewidth down. Some of the Cranking tables have big numbers in the cold start areas, so they may be worth looking at.

PL

[nissangts]

I agree with Pete about the crank enrich figures. Drop them a bit. If you want you can send me your bin and I'll make the mods for you.

[Matt]

Crank enrich tables definately need adjusting, otherwise can start fouling plugs before the engine can get going. Mulitple starting with those values will continue to foul further that you might not even get spark

[kg300zxtt]

well I was messing with latency started from stock 720 worked it down to 620 and so on till i got to 20 and no effect.

then started with the enrichment table and ended up on 0 enrichment no effect.

Yet I had 2 spare ecu's one auto 1 manual so i swapped in stock injectors and ecu checked everything adjusted timming and all kinds of stuff and managed to get it started. It was rough but after a few tweaks here and there with tps and aac valve got it to idle. The next day I timmed it again to get it just right then messed with idle air adjustment some more and now it idles much better . Had a few heat cycles to the engine ( its a total rebuild bored over so needed that) now it idles at 700 with air fuel jumping a little between 18-20.

But there still is a big problem im not using the nistune Ecu and 810cc injectors.

So i think I'm going n a right direction.

next I'm gonna try to swap back in the nistune ecu if that works out
eventually swap in the 810cc back in

thanks for the info you guys provided me hopefully I can use you're advice later on in the fine tuning process thanks again.

anymore ideas tips or tricks would be greatly appreciated.

[PL]

Latency will affect idle mixtures but for cranking it won't do a lot. It's working in the under 1ms range. Cranking times are in the 10+ ms range. So you really need to be looking at the cranking tables (specifically Cranking offset), TTPmin and of course K Constant.

PL

[kg300zxtt]

Good to know
latency is more for fine tuning idle at normal operating temp and no load

Others stuff are more affective when more fuel comes in to play and is needed to compensate for the extra mass of air coming in or when the car has to start or turn over when its not in a right operating temp.

[PL]

Yep. Most engines will handle (and need) A LOT of fuel at cold start. But this quickly tapers off as temp rises.

PL

[kg300zxtt]

So guys i managed to make the car run on the 810cc injectors and z32 maf

The issue now is that my car doesn't go to idle speed it sits on 1200 rpm (tps idle is not indicated red) and runs rich at 10.5 afr
if rpm fall below 1000rpm the car looses vacuum and dies when its at 1200rpm vacuum is on 15 and someone said it should be at 20
when i tap on the gas mixtures go to lean 32.0 max afr then goes back to rich
also after a while when changing k constant i noticed it doesn't have much of a affect on this
any ideas on whats wrong

1 stalls when goes to idle
2 afm mixtures are not consistent leans out on idle leans when tap on gas
3 vacuum decreases when car goes to idle

i changed my maf sensor to stock has no effect
checked for vacuum leaks with a smoke machine and no leaks.

car worked fine on stock injectors and stock ecu my guess is that i have to mod my fuel injection but not sure where because changing k constant has no effect on that problem