Carpokes

four0four wrote: Wed Apr 15, 2026 9:16 pm

944m3 wrote: Wed Apr 15, 2026 5:55 am I’m using a fuel pressure sensor. In theory the standalone reads actual fuel pressure and compensates accordingly. I’m also using the built in injector configurations for my Siemens injectors, which means the standalone deals with deadtimes.

But after your suggestion I’ll switch everything back to manual mode and see if anything changes.

What are folks seeing for pulse width and deadtimes at idle? My logs show at 13.41v 897 RPM my pulse width was 1.306ms and deadtime 1.007ms. Idle was steady.

that'll be it then - if you have the ECU applying corrections for fuel pressure (gauge pressure) *and* the FPR is referenced to the manifold pressure you'll have confusing/useless results like this. I think it would get quite dangerous to the motor under boost too: FPR drives up pressure to compensate for increased MAP, ECU pulls injector pulsewidth to compensate for "extra" fuel pressure...you get the idea

After some quick reading it seems like MaxxECU intends for this to be used to track deviations and as an additional safety measure. I suspect if you didn't set that up precisely correctly, it could have this effect. Maybe disable it for now and try to get things idling properly without? You can re-enable it later and use it as intended. The FPR mechanically tracks MAP pressure on its own, insuring that the injectors "see" whatever pressure it is configured to regulate to no matter the boost/vacuum level. ECU corrections should be just that: corrections applied on top to handle unusual scenarios, imo. I'm just some guy though!

fasterfaster wrote: Thu Apr 16, 2026 10:00 am

944m3 wrote: Tue Apr 14, 2026 5:12 pm Is a VE value of ~30 at idle to low?

I'm still dialing mine in, but I'm at 29 on my ClassicECU/Speeduino (stock injectors and 2.5bar FPR), so 30 doesn't seem crazy. If anything I expect to go lower once I'm more dialed in, as I'm running rich and fast right now, even at only 6 deg of advance.