Modelled fuel equation values seem high

[ellisd1984]

Could someone have a quick look at my setup for Modelled fuelling?  I've just swapped in a set of 1000cc injectors,  I'm running a fuel pressure sensor and a differential of 4bar.  I was going to use 3 bar but for some reason my FPR wouldn't go low enough when in vaccum when set to 3 Bar diff pressure  I seem to be getting really high number in the VE table and I'm starting to think I've missed something

 

https://www.dropbox.com/s/5vxitqmzlw7bw7q/Screenshot 2020-12-31 at 20.35.14.png?dl=0

[Adamw]

Can you attach the tune.

[ellisd1984]

I've attached a copy of the tune and a Log.  The only way I could get the car drivable was to turn CLL on and let it add up to 20 % fuel.

I wanted to set the base fuel pressure to 300kPa to give me a higher injector pulse width at idle however although I could set base to 300 with vacuum line disconnected. When I reconnected it the regulator wouldn't reduce by the same amount as the engine vacuum so differential pressure was rising to around 340 kPa.  The only way to get the differential pressure to stay constant is to set the base pressure to 400kPa.

I've inputted all the deadtime values I got with the injectors in a 3d table from CP Injection and have emailed them asking for short pulse width adder values (currently set to zero).  I've read A few posts about injector dynamics quoting incorrect values for Link ECU's  Is this specific to injector dynamics or is it the Bosch EV14 injectors as a whole? I belive mine are based on the same injector

1000cc i90%ve cll@20%.pclx 1000cc injectors 90% VE Closed loo +20%.llgx

[Adamw]

Your fuel pressure sensor cal looks very odd, is it an absolute sensor?  Im not sure if that is going to work well when baro changes.  Does fuel pressure read zero with the pump off?

[ellisd1984]

Hi Adam, all the best for the new year. 

Yeah the pressure sensro is absolute I had a bit of a discussion on the forum about it's suitability a while back

What I have done yesterday is moved the sensor from the top of the fuel filter (about 300mm before the fuel rail) and now mounted it into the turbosmart FPR.

Am I right in thinking that if I drop the static pressure back down to 300kPa the fact it doesn't reduce as far as the vacuum of the engine shouldn't matter, as the ecu can compensate for difference in differential pressure anyway?  It just means instead of running around 0.5ms injector PW at idle @400kPa, I can get it above 1 and hopefully closer to the linear flow of the injector.

[Adamw]

On 1/2/2021 at 6:13 PM, ellisd1984 said:

Am I right in thinking that if I drop the static pressure back down to 300kPa the fact it doesn't reduce as far as the vacuum of the engine shouldn't matter, as the ecu can compensate for difference in differential pressure anyway?  It just means instead of running around 0.5ms injector PW at idle @400kPa, I can get it above 1 and hopefully closer to the linear flow of the injector.

Yes it should work, however I doubt dropping your pressure by 20% is going to end up doubling your idle PW.  

[ellisd1984]

You're right it didn't but it did improve it.  I think I'm going to just bite the bullet and rewire the engine loom as I'm still having problems with Lamda leaning out with electrical load.  When I fitted the injectors I noticed that although the 12v side of the injector wiring looked quite beefy the ground side the goes to the ecu is absolutely tiny! and I've had a few connectors just break off because the wiring is so brittle. 

Can I just ask if for example i was targeting lambda 1.0 and I was at 0.9, if everything if set up correctly should a 10% change in VE equal and 10% change in Lambda?