This is going off topic, but I'm confused...
I'd have thought the MAP sensor is harder to work with than the MAF, as there's no volumetric flow rate known. A 1.4 ecu, would see, for example atmospheric pressure at full throttle (for arguments sake), and would know that this requires a fuel flow of X to burn with the air, in open loop fuelling strategy. The problem then comes, that when the 1.8 MAP sensor is seeing atmospheric pressure, the engine is actually drawing in about 30% more air than the ecu believes is the case, so to run at the same afr it needs 30% more fuel (roughly) than the ecu will be providing, but the ecu looks up 1 bar of air pressure, and only fuels for a 1.4.
Does the ecu get by the potential open loop fuelling problems, by noting the need for a massive fuel trim in closed loop, and applying the same offset on the open loop map?
The above obviously assumes the same injectors are used in the two engines, but if the injectors are proportionally matched to the engine, I can see a 1.4 ecu would run a 1.8 far more easily.
Just curious, that's all.
John.
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