Question:
From what I can tell, there is about a 10deg discrepancy in ignition timing, as in the mechanical timing is 10deg more advanced which is why we've had to retard the ignition timing map by 10deg. I believe it has to do with me adjusting the crank angle last night. With most engine management system software, there is a parameter to lock the timing at a user specified value so that ignition timing synch can be performed accurately without any trims affecting the specified value. Easimap doesn't seem to offer that so we are assuming it is taking the value at ~1000rpm x Site 0. Setting that area at 10deg let us to adjust the crank angle to synch but the ignition map still looks wonky. For example at WOT the ignition map is set to 10deg but mechanically it's operating at about 20deg. The car made 146whp my setup should be in the 200whp range
Answer:
If you are not familiar with MBE ECUs. I will try and keep it simple to explain what I believe you are seeing and why you don’t understand it.
The MBE system is designed to run on many production and pre-production vehicles and for this reason, it has many features to allow the engine to run perfectly even with a large number of sensors failed. I will explain below what I think they are seeing and not understanding.
1. The MBE ECUs do not require the cam sensor to allow them to start, this helps to prevent engines from not starting where they have to have a cam synchronisation before firing any sparks.
2. When the engine starts, it starts in wasted spark mode because it does not know which cycle it is on until synchronised from a cam signal, so during this time if you are checking the ignition with a strobe, the ignition value would appear to be double e.g. 10-degrees would appear to read as 20-degrees. It could be misunderstood to be an error of 10-degrees.
3. The software allows the user to configure when the cam signal is looked at to synchronise, this is called a ‘Cam Synch Window’ in most cases, this is set up not to happen at idle due to the fact that if there is fault with the sensor or ignition offset is 180-degrees out, if the wrong information is seen the engine could simply stop because of the synchronisation on the wrong cycle.
4. Most of the synchronisation windows are set around 2500-6000rpm at zero throttle. This means that the only way the engine will synchronise is if the engine is revved, the throttle is then closed and the engine will then synchronise at that point. This is a useful tool for fault finding with no equipment. If the owner of the vehicle calls up to say my engine starts but as soon as I rev it, it stalls then you have a pretty good idea there is a cam signal error, you would then ask them to remove the cam sensor connector and repeat the test. They can then use their engine quite safely as it cannot damage the engine, it will simply mean that the coils are in wasted spark mode and the fuel synchronisation may be synchronised to the wrong cylinder but this at worst would have a small performance loss on a port injected engine.
So the information given, it looks like the timing has been checked on start up, moved the offset thinking it is synchronised, then ended up with an error of the amount the the offset has adjusted by. Unfortunately, everything that has been done will have to be reversed and then everything re-checked, hopefully this will be where all your power is going but obviously there could be something else causing an issue, so this must be kept in mind.