[Super73]

In theory I don't for see a problem with a vette regulator inline prior the deadheaded factory rail with regulator. Reason being, the vette regulator should be holding the 58psi. Pressure should not creep nor drop through throttle changes. The factory regulator on the rail can't increase pressure beyond what the vette regulator is supplying. Could there be a further pressure drop, I suppose, but with the return blocked, it can't put the fuel anywhere except the injectors. So again, in theory, I don't see it dropping pressure either. You would need a guage on it through throttle transitions to confirm.

Have any of you ever put even an SVO 30lb injector in place of a stock 28lber? The SVO 30's are rated at 43psi (Ford rail pressure) and on an LS rail at 58psi, they act like 36lber's. They will not idle with out injector flow being plaid with or your foot holding throttle and rpm. My point, if the injectors have been changed with out the flow rate being adjusted, it wouldn't even want to run well idle or part throttle. If they are off by 2-3lbs, it might not be that noticable as the Ltrims are doing there job in closed loop, enter PE, go in to open loop and that might change. But simply adjusting PE EQ Ratio should get it in line.

If the truck is running decent part throttle, it is because the vehicle is in closed loop relying on the narrow bands to keep stoich using Ltrims. Enter Power Enrichment and it goes in to open loop. If the VE table does not match the MAF table, or if PE EQ Ratio is way off, guess what, it could be going way rich.

Things like Cat over temp settings will also cause an over rich deal.

Just curious, does this tuner have a track record with GM gen3/4?