where is this injector PW coming from???

[erics_02_z06]

did a log and saw a .3622ms being commanded. I've got my minimum set at .5 and the default the same. Where could it get .3622?19.hpt

[Pekka_Perkeles]

Check under transient fueling..

[blownbluez06]

What's up with your IFR table? flat across the board and kicked up ad 80kPa. Your Short pulse adder is zero'd out in the lower pulse areas, down to 0, so once you get below that threshold, it changes drastically. Your Offset vs. volts AC has a hump in it right at a critical area, which although small, can make huge changes in fueling and cause the car to surge and drive you batty. Where did you get your injector info?

If you're going to hack the injector data, there are some rules. I did some housekeeping. Try working from this one.

[erics_02_z06]

What's up with your IFR table? flat across the board and kicked up ad 80kPa. Your Short pulse adder is zero'd out in the lower pulse areas, down to 0, so once you get below that threshold, it changes drastically. Your Offset vs. volts AC has a hump in it right at a critical area, which although small, can make huge changes in fueling and cause the car to surge and drive you batty. Where did you get your injector info?

If you're going to hack the injector data, there are some rules. I did some housekeeping. Try working from this one.

well the IFR table I messed with because I have a boost referenced regulator and I wasn't sure how to account for it in the high MAP areas since the table runs out. The Offset vs AC was just a hack because before, I was running too rich and couldn't for the life of me get a PW less than 1.3

[blownbluez06]

well the IFR table I messed with because I have a boost referenced regulator and I wasn't sure how to account for it in the high MAP areas since the table runs out. The Offset vs AC was just a hack because before, I was running too rich and couldn't for the life of me get a PW less than 1.3

Fuel values in the IFR value vary because the pressure differential between the fuel rail pressure and the manifold vary and those values account for the pressure variation. A 1:1 boost reference accounts for the pressure differential by referencing the manifold pressure/vacuum, so that creates the need for a flat value across the board. The only time the IFR would need varying values with a boost referenced regulator attached is if there were some sort of floor that the regulator wouldn't go below or if the regulator reference was attached to any part of the charge path on the other side of the throttle body, where it would see boost, but no vacuum

[erics_02_z06]

Fuel values in the IFR value vary because the pressure differential between the fuel rail pressure and the manifold vary and those values account for the pressure variation. A 1:1 boost reference accounts for the pressure differential by referencing the manifold pressure/vacuum, so that creates the need for a flat value across the board. The only time the IFR would need varying values with a boost referenced regulator attached is if there were some sort of floor that the regulator wouldn't go below or if the regulator reference was attached to any part of the charge path on the other side of the throttle body, where it would see boost, but no vacuum

Thanks for the help! Ok, now that we have the IFR value set back to 96, do I need to retune my VE in the 80+ range? I'm guessing yes....

Can I just add 15% to the VE to help account for the change?

[blownbluez06]

80kPa is deep decel, so don't change anything until you log the car and see the need to.

[erics_02_z06]

80kPa is deep decel, so don't change anything until you log the car and see the need to.

Thanks for all the help! I'll take the file you gave me and start tinkering with it. One question....will changing the short pulse adder affect my fueling at all? Thanks again

[Pekka_Perkeles]

It will make your logs more stable during street driving. Also your wideband may have less amplitude in closed loop (i.e. values do not necessarily change that much as previously).

Funny, I just fixed a C5 Vette with bucking problem during trottle lifts by using correct injector data, including short pulse adder. Well ok, the max flow rate was right, everything else was wrong. Bucking went away and the fuel consumption went from 20.1 mpg to 27.0 mpg...without any other changes.

[blownbluez06]

Thanks for all the help! I'll take the file you gave me and start tinkering with it. One question....will changing the short pulse adder affect my fueling at all? Thanks again

Yes it will. If you're ever going to deviate from a known-good data configuration, you have to be careful. Some tables you can hack pretty hard and some tables will ruin your life with the slightest hiccup in the table.

[erics_02_z06]

Yes it will. If you're ever going to deviate from a known-good data configuration, you have to be careful. Some tables you can hack pretty hard and some tables will ruin your life with the slightest hiccup in the table.

Thanks for all your help. The car came with this injector data...but I am the one who zeroed out the short pulse adders for the lower end. I did it because I was hitting a 1.25ms limit at idle

If I was going to fiddle with a table, which table should I fiddle with to get a 1ms limit ( my car idles just fine around there)

[monte4ever]

What type of injectors are you using?