Idle VE table areas

[JHForman]

I guess I'm gonna have to pull these out and park the truck till I can save up for something else

[cobaltssoverbooster]

you dont have to spend $1000 for injectors just to get data. call deatchworks and ask about their injector characterization program. iirc the last person i sent to them said it was around $80 and they ask for you to send in one of your injectors and answer questions regarding pressures and fuel systems design.
if you dont think the data is correct and want to make these run you will want this done.

side note: ls3 and ls9 injectors are good to around 600 hp iirc. nice to have and the data is in the repository.

[5FDP]

You could sell your current injectors and buy Deatchwerks 72lb injectors too, those should support plenty of power on pump gas. Just another option.

[SSUte01]

EDIT: SSUte01: looks like he's done that... but perhaps not enough??

EDIT: I just looked, he's at 0.018, hell that seems low to me anyway, I'm at .028, and it's easily enough for my quite different setup..

They are very large injectors, either they have shitty low pulse width control or they are being limited. I see the 0.018, that is not enough IMO. There's a thread on here that walks through the calcs to determine this value. No harm in testing it. If not it and it's not airflow modeling then either accept poor low pulse width control, change injectors, lower base fuel pressure again, or change to a ethanol based fuel that will not see the same idle PWs.

[dermotw]

As SSUte01 says, you can just chop that value down from .018 and see what happens, or find/use the thread. If you decide to just change it, then halve it & see what happens..

kr D.

[JHForman]

I decided to scrap the tune I was working on and go back to a stock tune, I then put my 4l80e information in and started all over. No clue what I had turned on or off but something was that isn't now and the truck is idling 14.7:1 which is where I want it to idle. Thanks for the help guys now I feel comfortable making the changes to the VE table and shouldn't be all over the place with my numbers!!

[JHForman]

Something I did notice, if I look at my old logs my idle fuel trim cell was 20, when I would command closed loop it was trim cell 17, now when I idle I'm in 17 and not 20. Not sure if this was the issue or not but it is working currently

[dermotw]

Good that it's behaving, just change one thing at a time, this is a rule I frequently failed to follow and tripped up.. The cell mapping for the earlier LS1's like mine is;

0 - 15 defined by the LTFT RPM and MAP boundaries
16 - Idle PN (AC on)
17 - Idle PN (AC off)
18 - Idle InGear (AC on)
19 - Idle InGear (AC off)
20 - Idle (EVAP closed)
21 - Coastdown (EVAP closed)
22 - Non-Idle (EVAP Closed)

But for the later ones, it's a bit different, I <think> it's like this;

Fuel Cell Load condition Operating condition
0 Non-load Coast
1 Non-load Deceleration
2 Non-load Deceleration/Cruise
3 Non-load Deceleration/Cruise
4 Non-load Part throttle
5 Non-load Part throttle
6 Load Part throttle
7 Load Part throttle
8 Load Part throttle
9 Load Part throttle
10 Load Part throttle
11 Load Part throttle
12 Load Part throttle
13 Load Part throttle
14 Load Part throttle
15 WOT 100% load
16 Idle (Warm) A4 (P/N) A/C on
17 Idle (Warm) A4 (P/N) A/C off
18 Idle (Warm) In Gear A/C on
19 Idle (Warm) In Gear A/C off and evap on
20 Idle (Cold) All conditions
21 Non-load Moderate to high deceleration
22 WOT <100% load

Anyway, 17 would be ok according to either of those..

[JHForman]

Ok it's not fixed, I forgot to set the closed loop enable vs ECT table to not turn on closed loop!! Turned off closed back to idle 11:1 afr. Should I try tuning the VE with Fuel trims or is that a waste of time ? After I turned off closed loop at idle the afr error table told me it needed -26.1% taken off, I did this, let it idle again it's saying it needs -26% taken off again. Anyone have any other ideas?

[zbls2121]

I can only offer experience from my rich idle (and decel) experience. I am not running quite the large injectors but had a similar issue.

I am running LS9 injectors on a stock LS1 long block with LSA supercharger. 3bar OLSD. My issues were a few.

Read Injector Dynamics article. http://injectordynamics.com/articles...racterization/ Made me realize how very important the injector characterization data is.

Logged injector PW/Duty cycle.

Gathered the injector data from an LSA engine:
Minimum injector PW
Flow rate at 400kPa (58psi)
Short Pulse Adder
Default injector Pulse
injector flow rate vs volts

I then dropped my transient fuel milligrams from .045 to 0.030 (which you have even less of).

Went to a vacuum/boost referenced fuel pressure regulator since the PCM doesn't compensate for injector pressure delta above 100kPa anyway (0 vacuum). May not seem like it but the actual lower injector delta means the pulse width can stay "higher" and the fuel flow will be less at idle instead of compensating with injector PW via the PCM controlled injector flow model.

I was also having an issue during very light cruise (.1 to 2%) throttle where my idle spark and main spark tables were switching causing a lean/rich swing. I guess make sure timing is doing what it should be?

Good luck.

[JHForman]

My ID1000s should be here Monday, I will update this thread next week after I get them installed and all the correct data in. After all my research and reading and trying different settings and getting nowhere I decided to just bite the bullet. I am already running an adjustable boost referenced FPR, my truck was already a return style system. So from my reading my IFR table should be flat all the way across and so should my offset vs voltage table . Can anyone confirm this for me ?

[zbls2121]

Yes, your IFR table should read flat across the flow rate at which you set your regulator to at 100kPa (0 vacuum, or atmosphere.. same thing, basically whatever the injector data delta is). I run the fuel pump with the engine off, dial in the pressure (for me it is 58psi or 400kPa).

Double check when at warm idle; take your intake pressure and subtract that from the engine off state and your regulated rail pressure should match. Example, dial in fuel pressure to 58psi/400kPa engine off. Warm engine idle steady reads 30kPa manifold pressure, subtract 30-100kPa=70kPa delta. 70kPa=10.15psi. 58-10=48psi at that idle example.

Yes, injector voltage offset should be flat across the pressure delta (as you technically will have the same delta at any manifold pressure). Should still be a curve from low to high voltages.

[JHForman]

Id1000 installed, all data updated to reflect injectors, base fuel pressure set to 58 psi. It took about 10 times starting the truck to get it to stay running, the WB was showing extremely lean when it was first trying to start(18:1), as it warmed up the idle AFR settled around 13.5:1 but the cold start was terrible. Any ideas ?

[JHForman]

Current in work tune

[zbls2121]

A few questions regarding your warm-up and start-ability.

What was the commanded AFR/Lambda during the whole warm-up?

I noticed your open loop EQ and open loop EQ Alcohol tables don't match, not a huge deal but the commanded will then be an average of the EQ (which was all 1.00 at all temps) and your alcohol table which had richer values for colder temps.

Does it still take 10 tries to start now that you have purged all the fuel/air from the system? (10 still sounds like too many tries to start anyway).

Does Lambda perform as it should after everything is up to temp? If so, just the warm up/cranking fueling needs tweaking which isn't hard, just takes many cold starts. Use a fan to aid in cooling to get a few more cold starts per day.