VE Tuning Issue after Injector Upgrade. No issues tuning VE with previous Injectors.

[Mark2002]

Current configuration: 2002 Camaro Z28 M6, stock LS1 bottom end (aluminum flywheel), 212/221 .540/.540 (with 1.8 rockers), TrickFlow 215 heads, MSD AirForce intake, Nick Williams 102mm Throttle Body, 42lb FIC injectors

I recently changed the heads, cam, & rockers and tuned it with no problems (VE table, MAF table, idle air flow, and WOT). I had no issues with this and the car ran nicely, but I noticed I was maxing out the stock injectors so I purchased a set of 42lb Fuel Injection Connection LS1 injectors. After installing them and updating my working tune with the Inj Flow Rate, pulse width info & offset info provided by FIC, the car idled and ran nicely on the first test drive. However, I noticed when it entered Power Enrichment, it was running lean (~13.2AFR with a commanded 12.5AFR). Because of this I decided to go through the VE & MAF tuning process again.

The first step (as I did with the stock injectors on the same engine) was to target the VE table (logging fuel trim error with the MAF unplugged) . I had absolutely no issues doing this with the stock injectors. Now with the new injectors though, the car will not run with the MAF unplugged. The car will start fine, but soon after that the IAC starts climbing, the engine starts running rough, the RPMs trend downwards, the MAP increases, and I eventually shut it off. Applications of throttle to try to get it out of the idle mode does not help, and actually makes it worse.

I?ve attached two scans from the same tune: one with the MAF plugged in and the other without it (both had LTFTs reset prior to starting). The scan without the MAF is probably the best so far in that the engine mostly held RPMs above ~650, but still exhibited signs of getting worse. Some have gone as low as in the 300s before I shut it off.

I hope I?m simply overlooking something, because I?m stumped.

Thanks!

[5FDP]

Try failing the MAF in the tune instead of unplugging it. Set the MAF fail hz to 0hz in the engine diag tab and set code the MAF codes to MIL on first error.

[Mark2002]

I was able to try your suggestion this morning and it worked! Since I had tuned my VE table 4 times prior to this attempt, each by unplugging the MAF connector and never touching the MAF Freq Fail value, that was the last place I would've looked especially since the only change since the last tune was injectors. Thank you for that suggestion!