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Hey guys, i have a question. A mate and i have recently installed an sc14 supercharger on his 3800 buick VN calais. Immediatly after driving it, we noticed that the injector was being maxed out. So we ordered some L67 36Lb injectors.
i changed the crank fuel and voltage offsets to suit the injectors (pinched it from the vs l67 tune) and was able to get it tuned pretty quickly. However i noticed that injector duty cycle was still almost 90%. So i was wondering are there any settings that i have missed of anything to alter the pulse width as i believe (on the very small boost we're running) theres no way that these injectors would be maxed out like that. We are using 98 octane pump gas. These are the settings that i have changed.

1) Crank A/F Param Minimum drank BPW.
2) Map A Crank first stage Crank Base Pulse Width vs Coolant temp
3) Map A Crank second stage Crank Base Pulse Width vs Coolant temp
4) Map A Run A/F Param - Displacment/inj flow rate (Litres/Grams per sec)
5) Injector - Injector Bias vs Battery voltage
6) Injector - bias add-on vs Injector pulse width
7) The volumetric efficiency tables for tuning with a wideband for the appropriate AFR's

At first, i thought kinjflow was responsible for altering the injector pulse width. Cant seem to find anything about it. Ive been using THE1's VS-VY tunes and im fairly comfortable with them. But when it comes to $12p i have little experience with it. Any input is appreciated.

The only reason they would be at 90% is if thats what there using, so only way to get it down is make the fuel mixture leaner are you using a wideband & is your target being hit?

are you running the 3.5 bar regulator for those injectors? becasue the VN one is only 3 bar. So if thats the case, your injectors a delivering less fuel than they would otherwise.

the mixture is hitting the target spot on as it was with the old injectors. Would the flow rate be altered much by using the 3 bar reg instead of the 3.5 reg? it'd drop from 36lb to 33.3lb. the reason i ask is only because these injectors can handle the 3.4" pulley on the l67 motor no worries, this sc14 isnt running as much boost. 6-7 pounds if that.

rough calcs show that your in the ballpark. Stock boost for an l67 is what about 6 psi?. And your running less flow and slightly more boost. I reckon you might need 60lb dekas if you intend to go harder.

I believe linearity changes with pressure changes.

Also the dead times for ecotec ECUs have built in offset of 0.5ms if i recall correctly what The1 said, and 808 doesn't. So using the tables straight out will be incorrect.

The1 should be able to confirm this, I am thinking that could be part of the problem along with lower fuel pressure.

Also worth checking there is no exhaust leak anywhere as that can make the WB read heap leaner. I know of at least one person on here that had this problem. And it was only a tiny exhaust leak at that.

In 12P V112 there is a change to the injector PW item, but previous versions the PW changed with single and double fire. This meant the reported duty cycle doubled in single fire, even though that was not what was being delivered to the engine. Regardless of the version check that "Map X: set=Single fire option, clear=Double fire option" is clear. With an '808 it should always be clear.

High injector DC could be present because you have not connected the the fuel pressure regulator vacuum hose to see the boost in the inlet manifold. Check your fuel pressure under full load. 80% of the cars I see have fuel delivery problems.

thats true, without a boost reference to the reg, the boost will be fighting the injector pressure back limiting some of the fuel.

I ran l67 injectors on my buick with an sc14 and e85 at around 8 psi for quite a while, I never ran out of dc. Fuel pressure was 400 kPa. Power run on the dyno, 200 hp, 0.8 lambda all the way. I'm pretty sure they should be okay.