SR20DET won't rev past 3.5k rpm
Posted: Mon Jun 08, 2015 8:48 pm
I have installed my new DET3 and on the first test drive, after a few basic issues, I noticed the car missfired when trying to do a dyno pass. Some more trials and review of the logs show it just cuts out at ~3500rpm. With no load, clutch down and gentle reving the engine makes the familiar "bam bam bam bam" type noise, as if it was bouncing off an intentional rev limiter.
My settings are all identical to a friend who has an SR20DET, wiring is as-per the instructions, I have a wideband installed in analogue 3, analogue 4 is grounded. No spikes indicating a power cut. Sometimes the log shows a high AFR (18+) sometimes a low one (~11) immediately after the cut, but the constant is that the instant I feel a cut in power, the internal MAP sensor signal goes straight down to vacuum.
I've tried shuffling around the connectors and running either/or the CAS (cam angle sensor) or the MAF as factory, or through DET3, and have determined that it only does this when the CAS signal goes through the DET3 unit. If I run just the MAF through DET3, it runs fine.
If the CAS wire is broken totally, then the car doesn't even start up. So I know the connections must be OK and the engine gets some kind of signal through the DET3 to tell it to start and run fine. It just for some reason doesn't rev above 3.5k.
My launch control option is disabled, and nothing is connected to trigger it, but perhaps there's a glitch in the software and launch control is actually enabled? Perhaps if I "enable" launch control, then "disable" it again - it might jog the DET3 into coming out of this mode?
My settings are all identical to a friend who has an SR20DET, wiring is as-per the instructions, I have a wideband installed in analogue 3, analogue 4 is grounded. No spikes indicating a power cut. Sometimes the log shows a high AFR (18+) sometimes a low one (~11) immediately after the cut, but the constant is that the instant I feel a cut in power, the internal MAP sensor signal goes straight down to vacuum.
I've tried shuffling around the connectors and running either/or the CAS (cam angle sensor) or the MAF as factory, or through DET3, and have determined that it only does this when the CAS signal goes through the DET3 unit. If I run just the MAF through DET3, it runs fine.
If the CAS wire is broken totally, then the car doesn't even start up. So I know the connections must be OK and the engine gets some kind of signal through the DET3 to tell it to start and run fine. It just for some reason doesn't rev above 3.5k.
My launch control option is disabled, and nothing is connected to trigger it, but perhaps there's a glitch in the software and launch control is actually enabled? Perhaps if I "enable" launch control, then "disable" it again - it might jog the DET3 into coming out of this mode?