Constant misfiring at idle- NA6 Miata with MS DIYPNP
04-28-2020, 09:42 PM
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Constant misfiring at idle- NA6 Miata with MS DIYPNP
So I finished building my MS DIYPNP and have installed it in my car. No better time than quarantine to finally get this installed. I also posted this question over on the Megasquirt forum and the Miata forum, but I'm hoping to cast a wide net to get some good info. I am a noob when it comes to tuning and I don't really know what my issue is, only that my car is not idling on all of the cylinders. It's probably something stupid that I'm missing
My 91 is completely stock with a "cold air" intake, and Jackson racing 4-2-1 headers with an otherwise stock exhaust. I have installed a BMW VTPS sensor, a GM IAT, and an AEM UEGO AFR-gauge. I downloaded the base maps from DIYAUTOTUNE and made some adjustments following several sources online (mostly Carpassionchannel's and OGPedXing's youtube tutorials). It ran fine before I installed the Megasquirt.
I am currently just trying to get the car to idle properly. It sounds like not all the cylinders are firing. The exhaust smells like it's running very rich, but if it's misfiring that would be a factor.
-I assumed the misfiring was due to a mistake I made while assembling the board and that I had messed up the ignition circuit, though when I moved the timing light on the cyl-2 spark-plug-wire it flashed as well.
-When I checked the timing, it was at 10 degrees with the MegaSquirt installed.
-I am currently trying closed loop idle, it would not start at all in open loop.
-I did notice when looking at the log files that my timing error % is between +12.7 and -12.7, and my fuel VE is at 92% while [trying to] idle. I don't know what the normal values for this should be, but I felt it was worth noting.
-I have not pushed the throttle down more than a little bit, but this misfire continued up to 1250 RPM. It idles between 650 and 900 rpm (fluctuates throughout cycle due to misfiring)
Attached is the tune I'm currently running. If anyone can point me in the right direction, it would be much appreciated!
The below link is a google drive folder containing 3 separate data logs of startup. The first two are closed loop idle, and the 3rd is open loop:
https://drive.google.com/open?id=1e1...m9Y3yhunsV5oED
Thanks!
My 91 is completely stock with a "cold air" intake, and Jackson racing 4-2-1 headers with an otherwise stock exhaust. I have installed a BMW VTPS sensor, a GM IAT, and an AEM UEGO AFR-gauge. I downloaded the base maps from DIYAUTOTUNE and made some adjustments following several sources online (mostly Carpassionchannel's and OGPedXing's youtube tutorials). It ran fine before I installed the Megasquirt.
I am currently just trying to get the car to idle properly. It sounds like not all the cylinders are firing. The exhaust smells like it's running very rich, but if it's misfiring that would be a factor.
-I assumed the misfiring was due to a mistake I made while assembling the board and that I had messed up the ignition circuit, though when I moved the timing light on the cyl-2 spark-plug-wire it flashed as well.
-When I checked the timing, it was at 10 degrees with the MegaSquirt installed.
-I am currently trying closed loop idle, it would not start at all in open loop.
-I did notice when looking at the log files that my timing error % is between +12.7 and -12.7, and my fuel VE is at 92% while [trying to] idle. I don't know what the normal values for this should be, but I felt it was worth noting.
-I have not pushed the throttle down more than a little bit, but this misfire continued up to 1250 RPM. It idles between 650 and 900 rpm (fluctuates throughout cycle due to misfiring)
Attached is the tune I'm currently running. If anyone can point me in the right direction, it would be much appreciated!
The below link is a google drive folder containing 3 separate data logs of startup. The first two are closed loop idle, and the 3rd is open loop:
https://drive.google.com/open?id=1e1...m9Y3yhunsV5oED
Thanks!
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