Fic 30% injector tuning

[JASON11WS6]

Just added a set of 30% injectors from FIC and updated the data they provided. Fuel trims were in line and the car seems to drive okay. As soon as you open the throttle a bit the car just starts stuttering really bad.
I talked to FIC and they assure me this is a good batch. I look over the misfires and they seem to be random. Different cylinder every time.
FIC said it's in the tune and that a few more fields need to be modified. I was told the fuel pressure needs to be closer to 2600psi instead of 3000. So I capped the fuel pressure. Also, they said to raise the high current and low current tables. I added 10% and it got a little better. I added another 5% and it didn't do much. FIC advised not to go much higher then that.
Car still sputters but starts to smooth out once the high side pressure drops to 2600. It seems to build up to much pressure (2900-3100) when you initially hit the gas hard. I can't tell if it's the high pressure that makes it stumble or if the stumble is backing up the pressure.
Either way what do you guys do for these tunes?

[JASON11WS6]

Anyone else play with these injectors?

[JASON11WS6]

anyone tuning with these injectors? Anyone not running them for a reason?

[TriPinTaZ]

I've only tuned XDI's

[TriPinTaZ]

Tuning a built ZL1 with FIC 30's gen II injectors now. There is a stumble or misfire at part throttle. We are going to check the plugs first but if that doesn't solve the problem, then that means these injectors are a major pain in the ass.

[TriPinTaZ]

Turned out to be a cracked plug. So far I'm not having any issues with the FIC gen 2's but we haven't started WOT tuning yet. Regular drive-ability is fine though.

[GHuggins]

I'm tuning a set right now that is WAY off bank to bank - about 30% difference. Owner is checking for vacuum leaks and moving the injectors seems to cause the issues to follow. Problem is he's already sent them to FIC for cleaning and balancing twice now and they're always different when he gets them back from how they were when he sent them. Still not 100% sure the injectors are the whole problem, but they do seem to be very sensitive to rail pressure and changing a lot due to temps - higher pressure seems to bring them more in line with each other. Don't know, I may have something wrong in the settings - just have to re-verify with FIC.

[TriPinTaZ]

I'm tuning a set right now that is WAY off bank to bank - about 30% difference. Owner is checking for vacuum leaks and moving the injectors seems to cause the issues to follow. Problem is he's already sent them to FIC for cleaning and balancing twice now and they're always different when he gets them back from how they were when he sent them. Still not 100% sure the injectors are the whole problem, but they do seem to be very sensitive to rail pressure and changing a lot due to temps - higher pressure seems to bring them more in line with each other. Don't know, I may have something wrong in the settings - just have to re-verify with FIC.

I hav also found the FIC's are very sensitive to rail pressure. I tried changing the pressures to match what I use for the XDI's at low RPM and they did not like that at all but they seem to be okay on stock pressures in that area. I got the car driving good with the few changes FIC says to make and then adjusting the Density Multiplier. WOT tuning starts this weekend. I haven't noticed any large variance in fueling between banks and this car has a wideband on each bank too.

[GHuggins]

I hav also found the FIC's are very sensitive to rail pressure. I tried changing the pressures to match what I use for the XDI's at low RPM and they did not like that at all but they seem to be okay on stock pressures in that area. I got the car driving good with the few changes FIC says to make and then adjusting the Density Multiplier. WOT tuning starts this weekend. I haven't noticed any large variance in fueling between banks and this car has a wideband on each bank too.

I'm actually working on his density table and anything under 6 or 7 Mpa and it's WAY off bank to bank. Even around or above 7 Mpa and it's still off 10 to 15% bank to bank. He has an older set of injectors - I guess gen 1's, but they are not playing well and from what he's showed me with the flow numbers when he gets them back from FIC, FIC doesn't seem to care about them being really close to one another - they're always significantly different inj to inj on their flow numbers. Makes tuning in the density table that much harder. Runs smooth, but fueling is way off bank to bank. It's a silverado that's been turned into a 427 stroker with blower and other goodies. His other truck is running OE lt4 injectors I believe although now that I'm thinking about it they might be regular 6.2's - would have to look to verify that statement, but it's coming along nicely on it's density table tuning - usual 3ish percent off bank to bank. Does have some weird ridges at certain rail pressures which I haven't had on any others, but other than that.

[GHuggins]

Posting a follow up to be fair on this. Owner of the truck I'm tuning wound up changing injectors bank to bank - which did help some, but then he removed a valve cover breather - routed back to blower inlet and intake tube like OE and removed the vacuum line to the brake booster and installed a vacuum pump to run the brakes off of. He also replaced the plugs and now his trims bank to bank are probably some of the best I've seen - almost identical, so even though swapping injectors around seemed to change things - it wasn't the cause of the problem. I wasn't aware of the breather and everything changed on the ventilation and vacuum plumbing side initially, but we now have it back to redoing the density tuning and so far running better than ever...

[TriPinTaZ]

I finished tuning the FIC's on this ZL1 for WOT. It was mostly straight forward but they don't like pressures over about 2700 PSI. Any higher and they misfire as you roll into the throttle. I still need to work on the density multiplier for low pressure operating range. They seem to run way rich down low vs the XDI's or OEM's. Otherwise they haven't been much of a pain.

[GHuggins]

I'll keep the pressure in mind for later on as it looks like I'm going to need to pull that back down. Just now restarting on the 3Mpa tuning for them.