Question on tuning LARGE INJECTORS

[exploder]

No I am not done tuning the ve. I was told not to do any smoothing though....maybe I should.

[Bruce Melton]

I learned the hard way that the spray pattern of many of the SVO and non GM spec injectors CAN present a problem because you are spraying onto the floor of the intake runner where the fuel pools until you accumulate or blow it loose. The GM and later FAST spec injectors seem to spray higher toward the back of the valve thus are are cleaner burning. Watch for the decel black puff when using SVOs and note how tuning at idle results just seem sporatic and inconsistant.

I don't sell injectors so don't shoot the messenger. Just saw a dramatic difference going from SVO 30,36,42s to the GM LS7 and FAST 50s which use a different spray pattern.

[RacerChris]

No I am not done tuning the ve. I was told not to do any smoothing though....maybe I should.

Maybe I have thr wrong info but I always do small amounts of smoothing because the engine will respond better if it quietly goes from one cell to the next instead of beating down the door screaming more fuel/less fuel!!!!

[joecar]

That VE table is too spikey...

need to smooth it completely and start again, collect better data (no sudden throttle openings -- smoooth) and apply BEN filter (think about what has to be eliminated... any transitions that would cause a lag between wideband sensor below and PCM computation from MAP/IAT/ECT above... if PE is enabled, make it the same as the last few columns of OL AFR table)...

generally after applying AutoVE BEN, the VE table has some very minor spikes and doesn't really require smoothing.

[exploder]

Here is a copy and past of my old IFR table from when Ihad 60lb. injectors a long time ago.

69.26006
69.69410
70.12814
70.56218
70.99621
71.43025
71.86429
72.23632
72.67036
73.10440
73.47643
73.91047
74.28250
74.71654
75.08857
75.52261
75.89464

Min injector PW =1.246 across the board

Default injector PW= 1.246 across

Short pulse limit = 3.921

Flow rate modifier vs. volts = 1.00 across

[joecar]

Have you tried with negative small pulse adjust...?

[RacerChris]

Ok, So I zeroed out the min-inj. pulse width adder, I adjusted my min-pulse width to 1.55 and I played with the voltage correction table. What I ended up with was terrific results! It is now calling for more fuel in the under 40KPA area. I did a couple of logs making adjustments each time and I feel I got the VE table in pretty good.
Just wanted to say thanks to all that helped me on this one
Now I just need to start playing with my timing tables to get rid of this damn light bucking when my converter is locked up!
Thanks again!

[exploder]

Let me know what you do to fix the light bucking because I am having the same problem with mine.

[RacerChris]

Let me know what you do to fix the light bucking because I am having the same problem with mine.

I believe its because of timing in the off throttle area.
I will be making some changes and letting you know what happens.

[Goldfinger911]

I am running Lucas 42lb injectors at 64psi which makes them around a 50lb injector. Feel free to take a look at my tune (linked in my sig) I have them running very good, no stalling, perfect starting, 13.5/14:1 decel, 12.8:1 at WOT and almost dead-on VE Table.

Exploder- Dude, you gotta do something with that VE table. The problem with a super spikey VE table; is it makes changes to fueling so quickly, that further logging, unless it is filtered and %corrected only makes things worse.