E36 PNP Injector Pulse Width Drops to 0 in Boost

[JRHemmen]

After going back and forth with my tuner (and eventually being ghosted by him), I'm coming here in search of advice. 

I am having an issue in my tune where it seems my injectors are cutting out as soon as I get into boost. I have replaced my fuel pressure regulator, lines, pump (255LPH), fuel pressure relay & wiring, and have genuine deka 60lb injectors. My tuner thought I was not getting enough fuel to the rail and it was leaning out, but judging by how Injector PW drops to 0 and fuel pressure skyrockets, I think the injectors are stopping fuel delivery entirely. 

I don't know if this is caused by the overrun fuel cut table (or the temperature cut table, since it seems the values there are below operating temp), but I'm not comfortable making my own changes without seeking out advice here first. 

I moved my oil pressure sensor to the fuel line (pre rail), so the Oil Pressure graph in the attached log is actually fuel pressure. 

Thanks in advance!

5ms_rev6_new_pump_relay.llg 5ms_rev6 new psi.pclr

[Adamw]

Your RPM limit is set to 6000RPM, it will start cutting at 5800RPM (limit - control range).  As far as I can see the that is the only cut you have in that log.

Are you sure your oil/fuel pressure sensor has the correct calibration?  Your minimum fuel pressure is 125psi and it tops out at 166psi often.  

[JRHemmen]

I took a look in the tune and realized it is calibrated for a 150Psi sensor. I have a 0-100 sensor installed, and I have the values to input into a cal table to fix it. Is it possible to change the sensor to a cal table within this log? I am not physically near my car and won't be able to capture another log for at least a week.

[Adamw]

5 hours ago, JRHemmen said:

Is it possible to change the sensor to a cal table within this log?

No.  You could probably do something with a math channel in a 3rd party logging software but not directly in PC Link.

It still doesnt make sense if it was a 100Psi sensor either.  If I back-calculate your voltage based on the 150psi sensor, and you actually have a 100psi sensor, that would mean you had 111psi fuel pressure instead of 166psi.  But the sensor was maxed out most of the time so you had even more than that.  It should be more like 40-45psi.

So two things:

1. Verify your fuel pressure and adjust the reg to something suitable.  
2. Set the RPM limiter to something suitable.

 

[JRHemmen]

20 minutes ago, Adamw said:

No.  You could probably do something with a math channel in a 3rd party logging software but not directly in PC Link.

It still doesnt make sense if it was a 100Psi sensor either.  If I back-calculate your voltage based on the 150psi sensor, and you actually have a 100psi sensor, that would mean you had 111psi fuel pressure instead of 166psi.  But the sensor was maxed out most of the time so you had even more than that.  It should be more like 40-45psi.

So two things:

1. Verify your fuel pressure and adjust the reg to something suitable.  
2. Set the RPM limiter to something suitable.

 

Thanks for the help Adam. 

 

I ordered a new sensor (150Psi) so I can verify that my sensor isn't bad, and I can up the RPM limit as well. Next time I'm at the car I'll go over my vacuum lines and see if I can run a line directly from the manifold to the FPR, bypassing any T's I have in place now. I am using the stock FPR and fuel rail (FPR is brand new OEM) though, so it's completely vacuum controlled unfortunately.