2020 Mustang GT DI fueling issue since tune

[tording99z28]

Has anybody had an issue on cold start with DI fueling? When the car was stock it ran fine with no issues or anything on cold start and no codes. Added an ESS supercharger and ID1050X injectors. Now on a cold start for the first 20 secs the car surges and is having trouble with fueling going slightly lean then rich back on forth but only for those 20 secs or so. After that it straightens up and idles at lambda 1. Tuner says there is something going on with the DI on the car but I didn't touch anything with the DI and it never did anything like this when it was stock so I don't really understand how it could all of a sudden have a DI issue. Car also has zero codes being thrown currently. I do have a Lethal BAP on it but tuner says this shouldn't be causing it. Anybody have any similar issues or know something in the tune that could be causing this? Thanks in advance.

[mstang_man]

Has anybody had an issue on cold start with DI fueling? When the car was stock it ran fine with no issues or anything on cold start and no codes. Added an ESS supercharger and ID1050X injectors. Now on a cold start for the first 20 secs the car surges and is having trouble with fueling going slightly lean then rich back on forth but only for those 20 secs or so. After that it straightens up and idles at lambda 1. Tuner says there is something going on with the DI on the car but I didn't touch anything with the DI and it never did anything like this when it was stock so I don't really understand how it could all of a sudden have a DI issue. Car also has zero codes being thrown currently. I do have a Lethal BAP on it but tuner says this shouldn't be causing it. Anybody have any similar issues or know something in the tune that could be causing this? Thanks in advance.

Are you Running Return style fuel system? What Throttle body, CAI any other mods?

[tording99z28]

No, factory fuel system with a BAP. Keeping car on 93, not E85. I may try unhooking the BAP tomorrow and see how it behaves.

[mstang_man]

No, factory fuel system with a BAP. Keeping car on 93, not E85. I may try unhooking the BAP tomorrow and see how it behaves.

the bap should not be causing any problems, do you have the MAF data for your kit. Who is the tuner?

[tording99z28]

You can see here in this log what I am talking about. At the very beginning the STFT's go crazy for the first 30 seconds or so then they come down and line up +-5%.

cruise-4-small-WOT-7500.hpl 18+ CHANNELS 2-oil.Channels.Channels.xml

[tording99z28]

Are you Running Return style fuel system? What Throttle body, CAI any other mods?

stock throttle body, no airbox really. The ESS kit comes with a filter that sits in the fender on the inlet side of the centri blower. The MAF is in the intake tube in a straight section before the throttle body.

[mstang_man]

stock throttle body, no airbox really. The ESS kit comes with a filter that sits in the fender on the inlet side of the centri blower. The MAF is in the intake tube in a straight section before the throttle body.

Quick question is the BAP before or After the Fuel Pump Driver Module, if the BAP is after the FPDM it takes the control away from the PCM. The best setup is to have the BAP before the FPDM. And soemtimes the voltage table and PIDs need to be adjusted when using a non-stock pump setup.