Boost Cut Issues on Robtune Code 44
Posted: Fri May 05, 2023 2:48 am
Been a long time since I have posted in here! Not sure how much traffic there is anymore but here goes:
1992 Subaru Legacy with 550 robtune, VF23, TMIC, Grimmspeed mbc, Grimmspeed uppipe, 3" bellmouth DP with AFR gauge
Had issues with boost and idle. Figured out the uppipe had a hole in it and was causing a rich condition and problems with boosting. Just swapped that out with a new Grimmspeed uppipe and idle and everything in vacuum cleared up. In boost it would cut instantly in hard throttle but you could creep the boost up to about 12 psi under a lighter pedal. Around 12 psi it would start bucking or cut out completely.
Changed plugs, wires, O2 sensor and checked all vacuum lines and intake fittings. Gauge reads -19 vacuum at idle. Disconnected the MBC and ran wastegate pressure. I can ease in and then run hard after it spools and it boosts but sputters up around the 10 psi mark using just the wastegate. Ran D-check and came up with Code 44 for the "Duty Solenoid Valve (DSV) Inoperative". I had thought this Solenoid wasn't used with the robtune. In D-check I turned the ignition to on and listened for clicking in this sensor and there was none. Pulled the bracket and the long rectangular sensor (Jecs A15-000 R40) at the rear of the sensor bracket was plugged in. I unplugged it and plugged in the DSV, heard clicking with ignition on and light went away at start up and it fully boosted with no issue on the first pull. After the first pull the light came back on and all symptoms came back. However now it is throwing non-existent Code 43 at me.
I feel like I am just in my head and missing something obvious here. Is the DSV supposed to be plugged in? I had pulled these sensors to look over during this debacle and did not pay attention to which sensor was plugged in. There is only one plug available so it is one or the other.
1992 Subaru Legacy with 550 robtune, VF23, TMIC, Grimmspeed mbc, Grimmspeed uppipe, 3" bellmouth DP with AFR gauge
Had issues with boost and idle. Figured out the uppipe had a hole in it and was causing a rich condition and problems with boosting. Just swapped that out with a new Grimmspeed uppipe and idle and everything in vacuum cleared up. In boost it would cut instantly in hard throttle but you could creep the boost up to about 12 psi under a lighter pedal. Around 12 psi it would start bucking or cut out completely.
Changed plugs, wires, O2 sensor and checked all vacuum lines and intake fittings. Gauge reads -19 vacuum at idle. Disconnected the MBC and ran wastegate pressure. I can ease in and then run hard after it spools and it boosts but sputters up around the 10 psi mark using just the wastegate. Ran D-check and came up with Code 44 for the "Duty Solenoid Valve (DSV) Inoperative". I had thought this Solenoid wasn't used with the robtune. In D-check I turned the ignition to on and listened for clicking in this sensor and there was none. Pulled the bracket and the long rectangular sensor (Jecs A15-000 R40) at the rear of the sensor bracket was plugged in. I unplugged it and plugged in the DSV, heard clicking with ignition on and light went away at start up and it fully boosted with no issue on the first pull. After the first pull the light came back on and all symptoms came back. However now it is throwing non-existent Code 43 at me.
I feel like I am just in my head and missing something obvious here. Is the DSV supposed to be plugged in? I had pulled these sensors to look over during this debacle and did not pay attention to which sensor was plugged in. There is only one plug available so it is one or the other.