KPro 4 possible HF noise issue
Posted: Sun Aug 11, 2019 1:29 pm
We've been having an issue with out K24 swapped Miata running a KPro 4.
Under various conditions (seems somewhat random, but mostly noticeable in 2nd gear), we are experiencing an engine hesitation / misfire.
We have triple-checked fuel pressure, and that has been ruled out. This issue is either mechanical or electrical. Here are some images of datalogs showing the problem. It shows up between 11s and 15s in this log. We thought that it was related to lateral acceleration, but I don't believe that it is.
Note the sawtooch pattern in the RPM signal, accompanied by the MAP signal and injector output. This is a brand new MAP sensor (we also had the same problem with a 2nd new MAP sensor) and we installed a brand new Honda engine wiring and charging harness when assembling the car.
The VTEC pressure and VTEC signals all look to be high (1), so that is ruled out.
I am suspecting some sort of HF RF interference and electrical noise. Has anyone seen something similar, or have any suggestions? Our next step is to try and dismount the ECU and secure it in a way that is will not receive any HF vibration.
Injector outputs and the raw data log will follow in a reply.
Under various conditions (seems somewhat random, but mostly noticeable in 2nd gear), we are experiencing an engine hesitation / misfire.
We have triple-checked fuel pressure, and that has been ruled out. This issue is either mechanical or electrical. Here are some images of datalogs showing the problem. It shows up between 11s and 15s in this log. We thought that it was related to lateral acceleration, but I don't believe that it is.
Note the sawtooch pattern in the RPM signal, accompanied by the MAP signal and injector output. This is a brand new MAP sensor (we also had the same problem with a 2nd new MAP sensor) and we installed a brand new Honda engine wiring and charging harness when assembling the car.
The VTEC pressure and VTEC signals all look to be high (1), so that is ruled out.
I am suspecting some sort of HF RF interference and electrical noise. Has anyone seen something similar, or have any suggestions? Our next step is to try and dismount the ECU and secure it in a way that is will not receive any HF vibration.
Injector outputs and the raw data log will follow in a reply.