Misfiring when cold
Posted: Sun Jul 28, 2019 2:53 am
I have a fully forged turbocharged FN2 and mainly during the warm up phase I'm experiencing misfires if I depress the throttle pedal more than slightly. When the car is warm the issue stops.
As I am using Injector Dynamics ID1700x , I had to lower the target AFR because the car would misfire a lot in the warm up phase and less when it was up to temp. Now as Injector Dynamics advised since my injectors are big I am forced to keep the AFR around 13ish in order to avoid misfires. (Anything above 14.0 AFR causes misfires in general). I must also mention that I am using these injectors on Unleaded 100 gasoline thus the reason for a lower AFR.
I've noticed that the more I step on the throttle pedal the leaner the AFR ( 14.0 - 14.4 ) goes for 1-2 seconds causing the misfires during the warm up. I am also experiencing similar AFR behavior when I step on the throttle pedal and the car is already up to temp but I don't get misfires because the AFR stays below 14.0 . I am using a Honda J37 throttle body and my tuner already altered the throttle flow VS opening for that.
Could this be a throttle tip problem? If yes which table shall I alter "Tip in fuel ECT" or "Tip in fuel throttle compensation" ?
As I am using Injector Dynamics ID1700x , I had to lower the target AFR because the car would misfire a lot in the warm up phase and less when it was up to temp. Now as Injector Dynamics advised since my injectors are big I am forced to keep the AFR around 13ish in order to avoid misfires. (Anything above 14.0 AFR causes misfires in general). I must also mention that I am using these injectors on Unleaded 100 gasoline thus the reason for a lower AFR.
I've noticed that the more I step on the throttle pedal the leaner the AFR ( 14.0 - 14.4 ) goes for 1-2 seconds causing the misfires during the warm up. I am also experiencing similar AFR behavior when I step on the throttle pedal and the car is already up to temp but I don't get misfires because the AFR stays below 14.0 . I am using a Honda J37 throttle body and my tuner already altered the throttle flow VS opening for that.
Could this be a throttle tip problem? If yes which table shall I alter "Tip in fuel ECT" or "Tip in fuel throttle compensation" ?