[bowtie_thunder]

Preface: Torque tuning my N/A 2020 Camaro 2SS on E50 via VCM Suite Beta with the following mods

• 95mm TB (working properly)
• GMPP 6.2L CAI (MAF & VVE already tuned)
• Stock HPFP, LPFP & Injectors (I have the full LT4 system in the garage)
• GM Flex Fuel Sensor (Stoich AFR already tuned)
• Unlocked T93 TCM
• Stock Heads/Cam (for now)

I have only now noticed an issue with my Fuel Pressue (SAE) reading pressure, then zeroing out, followed by intermittent readings that read what looks like a consistent 55-65 psi (or higher, depending on E level--currently at E54), then zero out again. I've already ruled out the pressure sensor being an issue, as I'm not getting any DTCs related to that (nor any other DTCs, actually).


I'm not getting any DTCs for the LPFP or built-in regulator, but what has me concerned is if this is the sign of a pump that's failing. Rail pressure remains consistent, (though it spikes to ridiculous 90,000 psi readings like a flash in the pan at times). It could also be the dreaded VCM Scanner bug I've been hearing about for a while, too. But I'm just not sure.

Also what's complicating this somewhat is that I was getting knock in the midrange, and lean conditions in random spots on my STFT table (long-term looks good, however), but I attributed this to having too high of E level ( in one log, I was almost at 75 percent, fuel pressure at 72 psi, and my inj. pulse width was hitting damn well near 5.4ms @5000+ rpm). So I mixed it back down to the 50 percent range and that eliminated the knock. I also adjusted my High Octane and Min. Spark Base tables to back off the timing as well. Still, because of this, I can't rule out the possibility that having that high of an ethanol content didn't somehow damage the LPFP in some way.

I'm also well aware I'm very likely at the upper limit/max of my car's FS, and I have the LT4 system waiting to be installed. I'm just trying to do a before and after comparison on e50 for a project at work.

Any insight on this would be appreciated. Many thanks in advance!

[bishopts]

Can you log fuel pump command as a percentage? Maybe its dropping pressure and when it does you could see the pump command spike up. Or the other way around and it commands the fuel pump to shut off and then you see it in the fuel pressure.
I see ford fusion 2.0t come in all the time with a failure of running for a few seconds and then shuts off. If you dont know what you're doing you will sell the customer a low pressure pump. And then it will still do the same thing. If you watch fuel pressure desired vs actual vs mechanical gauge. You can see the fuel pressure sensor thinks the pressure is too high so it backs it down until it turns its own fuel off and it dies. Unplugging the fuel pressure sensor will let you drive those cars home when that happens.
In your case, maybe you have a sensor that is slightly off and what you're seeing is it trying to correct itself when it really doesn't need to. Or you just have a bad pump, or fuel pump control module.