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is there a way to increase the injector window, I see the soi and eoi but I'm not sure how far they can be pushed. anyone have information on this. I have good fuel pressure, I'm just getting a "torque max protection- injector limit" pop up right at 5500rpm.
any help is appreciated
thank you
Your close to the same fuel lbs/min I am stuck at with the injector limiter also. My issue is the lift pump voltage table is missing for the 15+ 3.5s so you can't raise the voltage to the pump to support more lbs/min so the PCM limits you. You may be running into the same issue. I have been waiting for a few months for the table to be added.
thank you for the info, I noticed that the truck pulls hard even though the limit comes up when the rpms get to redline. is there to change the injection cycle longer. I'm already starting 285.
I have the injector limit and other limiters kicking in even though they are maxed.
I do believe we are missing few tables or options within the software. I update the software almost weekly with no luck until now.
any way to boost the voltage to the pump? my rail pressure is dropping to 1900psi. the truck runs at 2900psi rail pressure.Quote:
Originally Posted by mrshanab
Hopefully the next update will contain the fuel pump voltage tables for all of the 2015+ 3.5 F150s. I put a request in 9/5/17 for that table. Eric said on 10/12/17 that it isn't in the beta yet but it is coming. I bugged them again last week but I haven't got a response. They are probably getting annoyed with me, lol.
Even with the limiter kicking in, i do not see my rail pressure dropping. Moreover, I have increased the pressure up to 3200psi and still getting the Injector limit and the pressure of 3200psi is actual, according to the scanner.Quote:
Originally Posted by cjg454ss
I would be worried if I am seeing 1900 psi.
Hey cjg, I didn't see on the log you shared your fuel rail pressure dropping to 1900, but you're also not hitting the fuel injector limit yet on that log either, you're hitting the popcorn limit and wastegate airflow limits. As far as the EOI Clip table, per a post from Bugasu the clip is degrees before top dead center. On the 2.7L I dropped it from 120 to 75 with no issues so far.Quote:
Originally Posted by cjg454ss
My reasoning is at the end of the fuel injection shouldn't cause any issues with preignition, and detonation won't be an issue until the spark, so the biggest 'issue' I could see would be having fuel still being injected when the plug sparks. Considering the advance on the pump gas I'm running doesn't ever go past 20, I would still be comfortable moving that clip even closer to the spark event. If anyone knows better on this please chime in.
The injector limit is calculated based on your maximum injection window, which is a function of SOI to EOI (so check your EOI Clip), and if that is sufficiently wide, the Injector Max Angle is the max window size.
Whatever that window size is multiplied by the Injector "DC" limitation and that forms your final limitation. This limitation is converted to a fuel mass amount, and then back calculated vs your desired AFR to a Maximum Airflow. If you start to hit or exceed this, thats when the clip becomes active.
If your high pressure is dropping regardless, you're running out of high pressure pump and there isn't some magic way to increase the flow of what is essentially a positive displacement pump with bypass. The ECU at that point will almost certainly be commanding 100% to the HPFP (log High Pressure Fuel Pump Regulator DC) so there's nothing more you can do.
That's all there is to the injector limit. If you want you can effectively turn it off as well by raising the "Airflow Limit Timer" to an obscene value, at which point your limit is 128lbm/min of airflow. Of course you're getting rid of the safety of the ECU saving your ass from going lean if you push more air than it can fuel.
As to the low pressure fuel pump side, from the factory the LPFPs I've seen have been more than adequate for factory HPFP. If you swap it in and want control of the low side fuel pressure and voltages, be advised, this doesn't suddenly make your HPFP pump more fuel for you.
Raising the feed pressure isn't going to help HPFP as much as you would hope, gasoline just isn't that compressible that a difference in 20psi will cause an HPFP that is filled to full volume will suddenly have much more fuel mass. I tried this quite a bit on the 2.0L Ecoboost platform when I owned one, but it didn't seem to have a big effect.
Back of the napkin, using the same values that the ECU uses to calculate the pressure rise in the HPFP for a given mass:
Bulk modulus of gasoline is 120000psi, we raised feed pressure from 60psi to 80psi in the HPFP volume (0.0683 cubic inches/stroke), fuel density 0.026 lbm/cu. in @60psi..
We get deltaP = (Mass of Fuel * Bulk Mod) / (Volume * Density)
Or in the way we want: Mass of Fuel = (deltaP * Volume * Density) / Bulk Mod
Mass of Fuel we added raising pressure 20psi: 0.0000003 lbm/stroke
At 7000RPMs with 3 strokes per cam revolution (so 3500 cam RPM), we've added 0.00315lbm/min, or a whopping 0.189lb/hr of fuel flow.
Regardless, you may want them just so you have control over your new low side pump, and as such the voltage tables / desired pressures for the low pressure side are on the table to get added, however, I should add that the value you see there is not the voltage that necessarily is applied to the pump. The voltage there is divided by current battery voltage to determine a duty cycle request from the fuel pump driver module (FPDM). The value is also wrapped in an adaptive table that learns whether or not the value sent is getting the desired pressure target met. Even if you calibrate this table, if you're hitting desired low fuel pressure, you wont suddenly get more fuel flow out of it, it adapts to the true value regardless. Something to keep in mind once its available. The point is simply to drive it so that your LPFP is hitting target pressure at the current fuel flow. You may not even need it (does your desired LPFP match actual? Not going to benefit from tuning this).
As well, depending on your application, you may not even have these tables available. Only electronic returnless systems will have this control over desired LPFP and "voltage". If you have Beta, you'll know if its possible to have that table if you have the Fuel Lift Pump Pressure Desired available for logging. If its not available, you have a Mechanical Returnless system, probably two-speed, and wont have a low pressure fuel pressure sensor anyways, so there's no such closed loop control of the system.
So the airflow limit timer has a max of 300 seconds. I have mine set to that and max torque source still goes to injector limit after 4500RPMs. Are you saying to go higher than that? I've had two different people tell me that it's limiting based on how much the PCM thinks it can support with the current fuel pump voltage. I can upload a log when I get home but if I remember correctly my HPFP is only 60-70% and pressure is meeting desired. I've also increased desired pressure, injection window, and max duty cycle with no luck.
From a separate discussion, this looks to be the case. Now I just have to figure out how far I can expand my injection window.
hi Puggy, did you drop all the three cells to 75 or only the one that was 120. I have three total cells, 135, 135, 120
I posted pics of most my fuel settings in this thread. These are for a 2.7, but a lot of it should carry over. On mobile right now so I can't easily link to the pics sorry.Quote:
Originally Posted by cjg454ss
https://www.hptuners.com/forum/showt...670#post508670