Fuelling Issues (ECUtek ROM) - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

Kodename47 · 03-16-2014, 07:21 AM

I thought I'd share some symptoms and asks for ideas and advice from some of the more experienced. 2 issues not related but occurring at similar RPM.

1st of all the PI seems to cut off for a brief period. It has no impact on the resultant AFR so it's not an issue but it's a tad strange. The PI/DI ratio table is as below:

But this is the injector open times:

Any ideas?

The other issue is that the car goes lean momentarily between 4.2-4.6k:

You can see the commanded AFR. The point it goes lean is bang in the middle of 2 MAF scalar points, the voltage points sit almost exactly at 4.2 and 4.6k RPM, so it's not a MAF issue. My initial thought is that as both intake and exhaust cams ramp up then the overlap increases as below:

My questions:
- Is the AFR actually true? You can see from the top images that the fuelling hasn't changed through that range. Is there a chance that the overlap is causing fresh air charge going through the cylinder causing leaner readings?
- Could the PI/DI ratio have an impact? I've moved the ratio back to stock from the tables above. The PI is showing as 50% in that range, but OEM is 100% DI. Could that help?
- Would just enriching out the fuelling table at 4400 be the right way to improve this?

Any other ideas?

Mark@Abbey m/s · 03-16-2014, 07:58 AM

The PI shut down but the fuelling is added via the direct injectors.

The switching between injectors is as the car was tuned from the factory.

Kodename47 · 03-16-2014, 04:22 PM

Quote:

Originally Posted by Mark@Abbey m/s

The PI shut down but the fuelling is added via the direct injectors.

The switching between injectors is as the car was tuned from the factory.

But at these loads I would expect it to be 100% DI between 2400 and 4800 as per the top map, not between 4500 and 5000. It doesn't really tie in with either map or be an interpolation between either.

For reference the cold map is stock, the warm and hot maps are both as the lower map shown.

Revolutions Performance · 03-17-2014, 12:50 AM

What's the load being logged when this happens?

Kodename47 · 03-17-2014, 05:13 AM

Quote:

Originally Posted by Revolutions Performance

What's the load being logged when this happens?

03-16-2014, 07:21 AM	#1
Kodename47 Senior Member Join Date: Oct 2012 Drives: UK GT86 Location: UK Posts: 3,040 Thanks: 185 Thanked 1,633 Times in 1,113 Posts Mentioned: 156 Post(s) Tagged: 1 Thread(s)	Fuelling Issues (ECUtek ROM) I thought I'd share some symptoms and asks for ideas and advice from some of the more experienced. 2 issues not related but occurring at similar RPM. 1st of all the PI seems to cut off for a brief period. It has no impact on the resultant AFR so it's not an issue but it's a tad strange. The PI/DI ratio table is as below: But this is the injector open times: Any ideas? The other issue is that the car goes lean momentarily between 4.2-4.6k: You can see the commanded AFR. The point it goes lean is bang in the middle of 2 MAF scalar points, the voltage points sit almost exactly at 4.2 and 4.6k RPM, so it's not a MAF issue. My initial thought is that as both intake and exhaust cams ramp up then the overlap increases as below: My questions: - Is the AFR actually true? You can see from the top images that the fuelling hasn't changed through that range. Is there a chance that the overlap is causing fresh air charge going through the cylinder causing leaner readings? - Could the PI/DI ratio have an impact? I've moved the ratio back to stock from the tables above. The PI is showing as 50% in that range, but OEM is 100% DI. Could that help? - Would just enriching out the fuelling table at 4400 be the right way to improve this? Any other ideas? __________________ .: Stealth 86 :. Abbey Motorsport/K47 Tuned Sprintex 210 Supercharger Kodename 47 DJ: Soundcloud / Instagram / Facebook

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03-16-2014, 07:58 AM	#2
Mark@Abbey m/s Member Join Date: Aug 2013 Drives: GT86 in Orange Location: UK Posts: 30 Thanks: 1 Thanked 32 Times in 15 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	The PI shut down but the fuelling is added via the direct injectors. The switching between injectors is as the car was tuned from the factory.

03-17-2014, 12:50 AM	#4
Revolutions Performance Join Date: Feb 2014 Drives: 2013 SWP BRZ RP Turbo Kit Location: Colorado Springs, CO Posts: 92 Thanks: 45 Thanked 51 Times in 28 Posts Mentioned: 4 Post(s) Tagged: 0 Thread(s)	What's the load being logged when this happens?

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