reprogram injector flow rates

[sprouse99]

Can efi reprogram the ecm for new fuel injector flow rates? lmm has the flow rate for each cylinder, which changes with injector swap out

[eboggs_jkvl]

EFI can be used to put new values into the table that controls IFRs if that is what you are asking. There is a Spreadsheet with the function to show new rates for different sized injectors. All you need is the injector size and the rated flow and you're all set.

Elmer

[nathans1987]

if i have the standard injectors do i leave the IFR {B4001} table the same as a standard tune? if not i am wondering how i calculate what it needs to be.

[joecar]

if i have the standard injectors do i leave the IFR {B4001} table the same as a standard tune? if not i am wondering how i calculate what it needs to be.Either way, you can measure your rail pressure and then use this spreadsheet: http://www.marcintology.com/tuning/injectors.xls

If you have an unreferenced regulator ("returnless" system), the spreadsheet is the IFR... you can compare with what you already have and decide if you want to paste.

If you have a MAP-referenced regulator (has a vac hose to it, located between rails), then the first value in the spreadsheet (at MANVAC == 0) is the value you use for all cells in the IFR table (flat horizontal across).

[nathans1987]

how do i measure it?

[joecar]

Do you have an EFI fuel rail pressure gauge ($50 from AutoZone or PepBoys), range is 0-80psi or 0-100psi... if you don't have one, you could just assume 58psi (stock), but that's just an assumption, pressure has been found to vary among vehicles.

[nathans1987]

Injector Rated Fuel Pressure:
Your Fuel Rail Pressure:
Injector Rated Flow Rate
i'm not sure what all these things do? the top two seem the same and i'm not sure how to find out the flow rate. sorry for dumb questions. thanks.

[5.7ute]

1) Injector rated fuel pressure: The fuel pressure the injector was rated at in psi. Most injectors are rated at 3 bar 43.5 psi.
2)Your fuel rail pressure: The pressure that your fuel rail runs at in psi. Our engines are around 4 bar or 58psi.
3) Injector rated flow rate. The flow rate of the injector at the test pressure in lb/hr.

For instance 60 lb siemens would be input as
Injector rated fuel pressure 43.5
Your fuel rail pressure 58
Injector rated flow rate 60
These are not exact numbers for the siemens , just an example.

[nathans1987]

so for standard injectors i put this in

Injector Rated Fuel Pressure: 43.5
Your Fuel Rail Pressure: 58
Injector Rated Flow Rate: 28.55

and got
Injector Flow (g/sec) 4.153804247 4.179692015 4.205420426 4.230992387 4.256410717 4.281678154 4.306797352 4.331770891 4.356601275 4.381290938 4.405842247 4.430257501 4.454538937 4.478688732 4.502709004 4.526601815 4.550369173
from the spread sheet and that is what i put in table B4001. its alot different to the standard tune did i do somthing wrong? or holden just not want the correct figures.

[joecar]

Post the IFR numbers from the standard tune file.

[redhardsupra]

use the one with correct units for your tables, there's a reason why there's multiple outputs of the spreadsheet

[nathans1987]

3.546875
3.601563
3.679688
3.875000
3.921875
3.984375
4.031250
4.054688
4.078125
4.117188
4.140625
4.171875
4.218750
4.250000
4.296875
4.351563
4.406250

that is standard what i had its not linier like the spreadsheet gave me and its alot lower. i had the rihgt units grams per second.

[joecar]

so for standard injectors i put this in

Injector Rated Fuel Pressure: 43.5
Your Fuel Rail Pressure: 58
Injector Rated Flow Rate: 28.55For the stock injectors, this number would usually be 58 psi also... are you sure you got this number correct...?

[nathans1987]

nope i have no idea what i was doing. i tryed to put the numbers in the correct boxes either there named badly or i still dont understand what each does, most likly the latter.

[nathans1987]

Injector Rated Fuel Pressure: 58 psi
Your Fuel Rail Pressure: 28.55 psi
Injector Rated Flow Rate 43.5 lb/hr


New Injector Flow Values
MAP (PSI) MAP (kPa) G/SEC LB/HR LB/MIN
0.0000 0 3.845465 30.520102 0.508668
0.7252 5 3.893998 30.905292 0.515088
1.4504 10 3.941934 31.285741 0.521429
2.1756 15 3.989294 31.661618 0.527694
2.9008 20 4.036098 32.033085 0.533885
3.6260 25 4.082365 32.400294 0.540005
4.3512 30 4.128114 32.763387 0.546056
5.0764 35 4.173361 33.122500 0.552042
5.8016 40 4.218123 33.477761 0.557963
6.5268 45 4.262416 33.829292 0.563822
7.2520 50 4.306252 34.177207 0.569620
7.9772 55 4.349647 34.521615 0.575360
8.7024 60 4.392613 34.862622 0.581044
9.4276 65 4.435163 35.200325 0.586672
10.1528 70 4.477308 35.534819 0.592247
10.8780 75 4.519061 35.866194 0.597770
11.6032 80 4.560431 36.194535 0.603242


is that how its ment to be done?

[joecar]

Injector Rated Fuel Pressure: 58 <-- The pressure at which the rated flowrate was measured/tested.
Your Fuel Rail Pressure: 58 <-- The pressure you measured on the end of your fuel rail.
Injector Rated Flow Rate: 28.55 <-- The flowrate produced by the injector when tested ("rated") at the rated pressure (see the first item above)

GM rates the injectors they use at 4 bar (58 psi)... same as the fuel rail pressure.

You have the stock 28 lb/hr injectors, correct...?

[nathans1987]

yep stock ahh ok i getfor some reason i thought the rated flow pressure was 43.5. thanks. its still a bit confusing tho the standard tune gets upto 4.4g/s the recalibrated one with that spreadsheet is only 3.9g/s at 80

[hquick]

if i have the standard injectors do i leave the IFR {B4001} table the same as a standard tune? if not i am wondering how i calculate what it needs to be.

If you're still using the stock injectors at the stock pressure...why change it?

[joecar]

He can use the spreadsheet to see how close the stock table has been calculated...

Of course, the other injector tables are also important and work together with the IFR table.