16 silverado 5.3 whipple sc ecu pulling fuel after 4k

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stock bottom end, texas speed stage 2 cam, LTH, dual 2.5 exh, cai is stock size diameter, LT4 throttle body, fuel pump and injectors, 10psi.
after 4000 rpm the ecu starts pulling fuel even though maf hz keeps going up. what goes down is cylinder airmass. which just seems impossible, if maf is going up how can that be going down?
so the whole kit goes lean. i change switchover to 400 rpm, or maf asap and it's the same thing. i make vve flat from 4k on and same thing. same on virtual torque. i add more PE and no change. injector open time just keeps going down after 4000. lt4 injectors are huge compared to stock 5.3 so can't be out of injector and fuel pressure moves a bit to the high pressure pump, but rail pressure is always good. plus you can see commanded injector open time is decreasing so it can't be pressure problem. what's going on here???

[kenand1988]

I'm not seeing where it is pulling fuel as you say. The log looks normal except there is quite a bit of knock with even very low timing so I would suggest some octane booster. Cylinder airmass does trail off, thats normal with this setup. Have you verified with a wideband that it goes lean?

[[email protected]]

yes, afr is low 13s when i let out near 5000 rpm. you can see inj open time is 5.2 at 4000 and then 4.3 at 5200. but maf is 9600 at 4000 and 10600 at 5200. airmass should not go down if maf is going up.

[MeshaalMMT]

tune is not complete

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yes. looking for answers as to why ecu is pulling fuel.

[GHuggins]

Try setting maximum fuel flow rate to 81.2 across the board.

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seems reasonable that would be in the fuel tab but i don't see it. there's flow rate which is the injector size. where is this table? thanks for reply.

[GHuggins]

Fuel System - Fuel Pressure - MAX

May not be your problem, but I've had nearly this exact problem on some boosted ones leaning out from torque management because of this table. These things go into safety protocols where they'll start cutting fuel due limit restraints.

[[email protected]]

would not of thought to look there. will give it a try, thanks

[[email protected]]

did not work. thought for sure it would, the values were really low. but it's same thing. always at 4000 rpm, it starts pulling injector open time. i have copied everything fuel related from an lt4 file, put driver demand 15% over what i see in the logs, tried dynamic airflow at 400 and 4000 and nothing stops this. new log (dyno run is at the end) and current file attached. any help is appreciated.

[GHuggins]

Try this one - just a random whipple file I had. Also don't know why you had it setup as TIAP, so changed the map settings back to the NA settings it should have unless you have rewired and setup for sciap in which case it would need to be changed to that. Think that may have been the problem - possibly running off of some pressure drop settings at that point.

Use these channels too as we might possibly see some wideband data with them along with some better torque command info.

[[email protected]]

i don't recall changing it to TIAP. looking at 15 and 18 silverado files i have they are NA-TIAP as well. LT1 camaros are too. but this is worth trying. will let you know. thanks again for the help.

[[email protected]]

road test in 3rd and not sure if fixed or not. fuel at 5000 vs before is better, but it suddenly went closed loop at 5700, that's not good. cylinder airmass is still going down though, and like the fuel, not as much. used your pid list so maybe something stands out. enough to warrant putting back on dyno again.

[GHuggins]

I'll have to look later tonight but that'll most likely be your torque and torque model settings.

[GHuggins]

Pretty sure your problem now is your peak torque setting - could have even been part of the original. You don't max or raise this like that. It's used for PE fueling.

Although I honestly have never seen one use stft fuel corrections while in PE or open loop. Would be nice if they had that capability with built in widebands - in fact with all the torque modeling why don't they :/

You also never tuned in your VE - lots of torque calcs going off of that. Feel like I'm tuning this thing now

Anyway - this one has VE settings for boost - just used a general boost VE table I had - not right for yours and will need tuning in. Also made a small tweak to your soi and changed the peak torque and max map settings.

I should also note that I have not looked through your whole tune, so other stuff may still be wrong. I know your density table is wrong - you don't just copy that table because you have those injectors - everything that changes airflow into the engine changes it, but I also know you're probably not going to tune that in as it requires some special maths that you need to come up with and I'm not going to share mine BUT, if you're able to - it's easy to come up with as long as you have some understanding of how it works and what does what then make a math based off of fuel correction for it.

I also still don't see a wideband in the log - you are using one aren't you?

Either way, hopefully this one gets your current problem sorted.

[[email protected]]

Pretty sure your problem now is your peak torque setting - could have even been part of the original. You don't max or raise this like that. It's used for PE fueling.

*32920 peak engine torque? that table is up from stock, but not set to max, probably 100 over what it's doing (610 pd ft). if not right table please tell me.

Although I honestly have never seen one use stft fuel corrections while in PE or open loop. Would be nice if they had that capability with built in widebands - in fact with all the torque modeling why don't they :/

*yes the dodge s/c are like this and it's great. you can log error and then just use it on next flash. so stupid gm has no widebands on anything. but did you notice trims were + and 02s were going lean? wth...

You also never tuned in your VE - lots of torque calcs going off of that. Feel like I'm tuning this thing now

*will not leave you hanging on this. no i did not. normally don't need to, even the virtual torque doesn't need touched. did lt1 to everything lt4 on a vette and didn't have to change any of that. sometimes only change what you must works and sometimes it doesn't.

Anyway - this one has VE settings for boost - just used a general boost VE table I had - not right for yours and will need tuning in. Also made a small tweak to your soi and changed the peak torque and max map settings.

*how did you get ve table so expanded? i don't see a code patch for it. it's a LOT bigger. soi was already pretty good i thought at 360. max map was 190, i think it's 165. headroom i guess.


I should also note that I have not looked through your whole tune, so other stuff may still be wrong. I know your density table is wrong - you don't just copy that table because you have those injectors - everything that changes airflow into the engine changes it, but I also know you're probably not going to tune that in as it requires some special maths that you need to come up with and I'm not going to share mine BUT, if you're able to - it's easy to come up with as long as you have some understanding of how it works and what does what then make a math based off of fuel correction for it.

*i don't know this needs that. if this truck makes 600whp all will be happy.

I also still don't see a wideband in the log - you are using one aren't you?

*the dyno has a motec wb, today to speed things was just on-ramp test, no mobile wb. but even at dyno, i don't input it to hpt, easy enough to correlate on the big screen vs the laptop.

i'll find time to get it back on dyno. going to put it back to NA-TIAP as it does not drive as nice.

thank you again.

[GHuggins]

If you don't tune the VVE or torque model IT WILL burn up transmissions and have all sorts of problems after adding boost. May not happen right away, but given time and the right terrain such as hills and mountains to pull or even a loaded trailer for example, it will burn it up...

It's not driving as nice because of the torque model and VVE. You change the boundaries settings to expand it out. I set yours up to see boost as it wasn't setup that way prior.

It needs the density table dialed in. If fuel trims are one thing idling on a cold start and then change to another idling after a few dyno pulls, then it needs dialing in. This throws off your torque calcs too as they are based off of fuel calcs.

The map settings I changed were for the torque model...

You should be able to open the one I posted as a compare file to see the settings I changed. Even what I changed them to should be higher than what you're making.

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good news, fixed! it was simple and something that i thought i had already done, increase the maf table. always double and maybe triple check.... this has bit me before on truck stuff. the maf has values all the way out to 15000hz, but around 9500 they're not valid. it's like the engineers said we only need this much. the fuel system tab, fuel pressure tab, pressure limits, maximum, max table, is the same way. the numbers dive. that table can really screw you up even on a stock pump and big cam. that's one thing to remember on the trucks, they only seem to go so far. everything ghuggins said valid as well, especially about protecting the transmission. did all this and now truck is golden. 631whp and 610 torque on 9.5psi and 91 octane and that was stopping at 6000rpm. big thanks to greg.

[GHuggins]

You're welcome sir.

Glad you got it fixed. I've never looked at all of the truck tables past a certain point from a point of view like that. That's a Good point and good observation...