Decided on a replacement for Go Man Go

[fumanchu182]

From the FSM:

P0308-CYLINDER 8 MISFIRE
Theory of Operation
The PCM uses the Crankshaft Position (CKP) Sensor to detect and monitor the Crankshaft rotational speed. Normally, the Crankshaft rotational speed is fairly stable from cylinder to cylinder. When a misfire occurs in a cylinder, the Crankshaft speed changes abruptly for that cylinder. Therefore, anything that causes a sudden change in Crankshaft speed detected for a single cylinder is determined to be an engine misfire event. A misfire fault will usually occur due to poor fuel quality or metering, lack of spark, engine timing, low engine compression due to engine mechanical or valvetrain issues, a vacuum leak or coolant leak entering the engine intake air system. Though not as common, other factors such as severe wheel balance or braking vibration, a worn serpentine belt or belt driven accessory binding should also be considered when diagnosing a misfire fault.
Depending on the engine involved, there can be several systems and components that can contribute to a misfire. In many cases, but not always, there will be other DTCs set related to these systems. If that is the case, the focus should be on following the diagnostics for the system that has DTCs set against it. The different components or systems will affect misfire in different ways. Factors to consider when diagnosing a misfire are whether the misfire is a single cylinder or multiple cylinder misfire, and when does the misfire occur (idle, vehicle and engine speed, heavy engine load conditions, etc.). These factors can help in determining what components or systems should be focused on during diagnostics. Typically a multiple cylinder misfire is an indication of timing, oil or coolant consumption, air handling, fuel supply or poor fuel quality issue that can affect multiple cylinders and not a single cylinder component such as a Fuel Injector, Ignition Coil or Spark Plug.

When my cylinder would shutoff it was a number of misfires over time or load. There is no channel to determine which table is used in the PCM calculations.

So think about what is happen when you start making hella boost. You start rotating the CKP Sensor faster than expected, well the PCM is thinking it has a misfire issue and ups the counter. I know this to be a false issue for me because the logs tell me so. Without the misfires nannies the knock sensors are happy, the fuel is happy for the air entering the engine.

Also food for thought... firing order is: 1-8-4-3-6-5-7-2

Also in the FSM and above: "Normally, the Crankshaft rotational speed is fairly stable from cylinder to cylinder. When a misfire occurs in a cylinder, the Crankshaft speed changes abruptly for that cylinder".

Well jumping from 1-8 on opposite sides of the engine... also for 7-2 isn't doing anyone any favors in this calculation.

 

[Speedy!]

Good info. On my 170 I've only ever seen like a max of 15 for misfire on a single cylinder and all occurred at idle.

 

[jonx96]

Almost every stock engine car I do mis fires can be left alone. There have been a few exceptions. Mis fires are also set for emissions reasons. I’m not on a computer but there’s other tables than those for weights. But it gets to the point of shutting off detection and jacking up the tables are about the same thing.
I think I’m the only tuner I’ve ever seen monitor mis fires. I have used it to help with injector or fueling issues. But if the customer sees it they tend to get excited