Rough running - ZR-1 Net Registry Forums

XfireZ51 · 10-19-2016

Just reviewing the stumble log, what I see is that the secondaries are not opening until 40%+ of TPS opening. MAP kPa is really low at 15 for decel so the motor is operating at the low end of the VE table. Also Spark Advance jumps momentarily from 10d to 25d then drops back to 10 and gradually progresses from there. A bit of Knock Retard as u shut throttle for decel BTW.
Right side running leaner than left for longer period of time, so again I think you r taking a big gulp of air and not compensating for it. O2 sensors appear to be operating nominally. As for replacing them, I have opted for the AC/Delco's rather than the Bosch. Don't know about Denso.

10-19-2016	#11
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,709	Re: Rough running Just reviewing the stumble log, what I see is that the secondaries are not opening until 40%+ of TPS opening. MAP kPa is really low at 15 for decel so the motor is operating at the low end of the VE table. Also Spark Advance jumps momentarily from 10d to 25d then drops back to 10 and gradually progresses from there. A bit of Knock Retard as u shut throttle for decel BTW. Right side running leaner than left for longer period of time, so again I think you r taking a big gulp of air and not compensating for it. O2 sensors appear to be operating nominally. As for replacing them, I have opted for the AC/Delco's rather than the Bosch. Don't know about Denso. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX Last edited by XfireZ51; 03-08-2024 at 03:10 PM.