Intermittent Port Injection During 100% DI Operation

[BRZoomTX]

I am forcing 100% direct injection. EcuTek B01C on RR 12.1, 42154.

While running 100% DI the car will intermittently switch to 50% port injection. It hits 50% PI then immediately switches back to direct. This will usually happen two or three times throughout a 30 minute cruise. While driving I thought it was the CL/OL transition, but it occurs during steady CL operation.

It is not causing a problem for tuning, however I am curious as to why the ECU is doing this. I've attached a screenshot with my PI/DI ratios and log sample.

I initially tried to force 100% DI through custom maps, but something else in the ECU was overriding the fuel ratio output. Fuel ratio would switch rapidly from 0% to 100% with my map enabled. Using the stock ratio maps gave better results beyond the intermittent hiccup.

Has anyone else seen this before? Is it typical with these ECUs, or is it possibly a bug in EcuTek / RR 12.1? I don't recall seeing this issue when I last tuned the car with RR9.

[tomm.brz]

i think it's hard coded into ecu logic

Like Before it warms up, the ecu will force switching to 50/50% PI/DI during idle and overrun

i would just deal with it

it should fully work 100% DI all the time once car is hot, at least it worked for me years ago
I wouldn't be surprise also if it's a Racerom bug in your case


EDIT: just saw now lol, you have B01C ... US tunes are super bugged with latest racerom
Switch to A02G or A01G and everything will run much better
I saw that behaviour multiple times while helping guys here, and they all were fixed by converting to euro tune

If you're boosted , US tune produces strange offsets and compensations, so that when you switch to an Euro rom, it requires a full retune because maf will be much different

[DarkPira7e]

Can confirm at least that I had nothing but issues running Racerom with B01C on my '13. A01C resolved them for me though

[tomm.brz]

i think i skipped a01c because even if less bugged , it made strange calculation for PI fueling on boost compared to euro tunes, and that messed up with my habits
As, if you start with it it's no problem... but if you copypaste it into an Euro rom, afr goes really wild

[BRZoomTX]

Thanks to you both. It is good to have confirmation it is not just me.

Originally Posted by tomm.brz

i think it's hard coded into ecu logic

Like Before it warms up, the ecu will force switching to 50/50% PI/DI during idle and overrun

i would just deal with it

it should fully work 100% DI all the time once car is hot, at least it worked for me years ago
I wouldn't be surprise also if it's a Racerom bug in your case


EDIT: just saw now lol, you have B01C ... US tunes are super bugged with latest racerom
Switch to A02G or A01G and everything will run much better
I saw that behaviour multiple times while helping guys here, and they all were fixed by converting to euro tune

If you're boosted , US tune produces strange offsets and compensations, so that when you switch to an Euro rom, it requires a full retune because maf will be much different

I’ve seen some of your other posts regarding the euro maps. I will do more research and check them out.

This is the first “problem” I’ve ran into on B01C. Open loop was on target with stock injectors and I didn’t notice much problems other than some tip in knock. I will watch more closely for any issues once I get into boost again.

[tomm.brz]

Don' t waste time and fuel with B01C, it won't change
go back at least to A01C , see if it improves and you can tune it without annoying things popping out like this

[BRZoomTX]

EcuTek responded, I figured I would at least follow up with their response:

We have seen this reported before but have not managed to find out exactly why it happens although it has been investigated by our dev team.

We think it is a strategy "hard coded" to the ECU that fires the port injectors intermittently to clean the inlet tract and the back of the inlet valves in an attempt to deter carbon build up.

I'm sorry but at this time we do not have a solution for this although I will re-open the investigation to have it looked at again.

It sounds plausible to me. I will worry less about it since they have seen it too. With properly scaled injectors the problem is not noticeable without looking at a log. It caused a hiccup before my PI was dialed in but now it is gone.

I am still on B01C so far as I haven't noticed any problems myself outside of this, and I've been looking at logs quite closely the past couple days. I have DI nearly running a steady 4.5ms throughout pulls and I haven't observed any hiccups in my fine tuning of the PI ratios. I did have one problem but it was because I missed adjusting the PI ratio lower limit. Fueling is on target apart from that. This seems to be limited to closed loop operation, which would make sense and fall inline with EcuTek's description.

@tomm.brz I've taken note of yours' and others' info about 10% difference in the VE tables on B01C. I am still running MAF because I am not running above wastegate again until I have rocker keepers, so I do not have a reason to try SD yet, but when I am more dialed I can do some tests and see what I find.

I understand there are some issues with B01C but I am the type who likes to see/experience the problems before justifying changing something. I believe you about it, I just want to see it first.

A good test will be taking A01C as well as a patched euro ROM and seeing if the intermittent 50% PI persists. I can try it sometime in the next couple weeks if anyone else cares to see the results.

[Ultramaroon]

Originally Posted by BRZoomTX

EcuTek responded,

Just saw this thread. On seeing pics in your OP, my immediate thought was "Nice! Quick rinse cycle."