VE table maxed out at idle.

[FsDevelopment]

Hi.

I am trying to understand why I have to max out my VE tabel in idle. 

Car is a fresh build and started first time today.

Please see attached tune and logfile.

ECU - G4X 350Z plugin.

Engine - Toyota 1JZ GTE VVIT.

Car - Nissan 350Z.

Fuel - E75 at the moment. Should be E85 when car gets tuned.

Injectors are Bosch Motorsport 1300cc flow matched set, EV1 connector.

Not sure about the dead time values I found on some forum. Can anyone confirm or dismiss?

Dead time values I found and use:

 

 

Don't know how similar Bosch 1300cc injectors are compared to Injector dynamics 1300cc.  

Here are values from ID 1300X injectors as a reference:

Conversion bar to psi:

2bar - 29psi

3bar - 43,5psi

4bar - 58psi

5bar - 72,5psi

6bar - 87psi

 

Base fuel pressure 3 bar without vacuum on idle.

I don't have a fuel pressure sensor. Just a guage on my regulator.

I have not verified my fuel pressure guage with another one yet.

Fuel pressure set to MAP reference. 3 bar.

 

Thanks in advance guys! :-)

 

 

PC Datalog - 2023-07-20 12;06;51 am.llgx Robins startad..pclx

Edited July 20, 2023 by FsDevelopment
Added info.

[Confused]

That dead time table looks very off to me on the top row for 14 and 16v, I think someone has offset that by a factor of 10, it should probably be closer to 0.80 and 0.65

 

This is another case where trying to save a few quid on injectors ends up costing way more in the long run in terms of time messing around, rather than just being able to plug in the known verified data and be happy!

[DerekAE86]

12 hours ago, FsDevelopment said:

Dead time values I found and use:

12 hours ago, FsDevelopment said:

I don't have a fuel pressure sensor. Just a guage on my regulator.

Because you don't have a fuel pressure sensor the ECU doesn't know which row in your deadtime table to use so is just on the first row.
Which as Confused has said is 100% incorrect. (far too low at 14 & 16v)

Until you get a fuel pressure sensor you can just edit the deadtime table to be like this: (remove the Y axis or change to 2D table)

This copies the ID1300x data you've provided above and assumes 300kPa/3bar/43.5psi since that's what you've set your regulator to and configured the flow rate at.

[FsDevelopment]

Hi.

Thanks for your answers.

Bought the car as a almost finished prodject. Injectors included 

I have now verified fuel pressure with another guage. Pressure is 3 bar at idle without vacuum.

I have changed to dead time values from ID1300X injectors instead.

I also noticed that my injectors are rated 1300cc @ 4bar. (Had this setting @ 3bar before)

 

Car runs much better but still high VE numbers.

See new tune and logg file attached.

 

Are you guys sure the ECU can't read 3D table from dead time with help from MAP referenced fuel pressure?

 

PC Datalog - 2023-07-20 2;45;00 pm.llgx Robins startad ID1300X dead time value.pclx

[Confused]

Look at the crosshairs on the table when you're running - this will show you exactly where it's grabbing the value from.

Also, what's up with your Warmup Enrichment table?

 

[DerekAE86]

6 hours ago, FsDevelopment said:

Bought the car as a almost finished prodject. Injectors included

Are you 100% positive these are 1300cc injectors? Maybe the seller was telling you fibs?

[essb00]

6 hours ago, FsDevelopment said:

Are you guys sure the ECU can't read 3D table from dead time with help from MAP referenced fuel pressure?

Y-axis on your 3D table is Fuel Pressure, while you don't have a fuel pressure sensor connected (and assigned from analog input). So ECU effectively considers it off Y-axis scale and only uses the 300kPa/43.5psi values on the table.

...if ever you've got a fuel pressure sensor, Y-axis should be 'Differential Fuel Pressure' to make it work as intended.

[koracing]

I agree the 3D dead time table should be differential fuel pressure, not just fuel pressure as it is a map referenced fuel system.  An injector that flows 1300cc at 400kpa differential will flow 1125cc at 300kpa.  It is very possible the injector flow is incorrect as that would make the most sense with what I'm seeing in your tune, but some of the other information below may be contributing to the high VE values.  Has the car been driven on this tune and logged?

Other things I notice:
1. You have IAT mode on, but it should be off in Modelled mode. 
2.Your acceleration enrichment is zero and wall wetting compensation is zero so that's probably contributing to why someone felt it necessary to max out the fuel values approaching 100kpa MAP at rpms near idle speed. 
3.Your fuel composition values (Fuel density, temp coeff, and stoich ratio) are .7824, .001069, and 9.75 for 85% ethanol, but at 75% ethanol should be .778, 0.001055, and 10.425.  That's going to have some impact on the calculation.
4.Youe pre-crank prime is off - so it makes sense why your values around 100kpa on the fuel table are so high there as well.  You have a 3D cranking enrichment table that has every row the same - yet you have a post start enrichemnt table that is extremely different than the cranking enrichment table and is only 2D.  Doesn't make sense to me.
5. I would recommend enabling idle igntion control as well.

Beyond this - flow should be verified on the actual injector and dead time should be checked and corrected to your setup in that car with your ecu as this can also play a big role in the VE value accuracy on the fuel table.