2.7L Port and Direct Injection Usage

toughtoaster

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I'm curious if anyone knows how the 2.7L implements the Port and Direct Injection fuel mapping?

Recently watched a video of Engineering Explained about the 2022 Subaru BRZ and how it uses port and direct injection towards the end of the video. Essentially it uses port only on start up then transitions to port and direct until the catalytic converter is heated up then transitions to port to warm up the engine and switches to direct injection 100% after everything is warmed up.

Heres the part of the video where he talks about it @ 14:17 -

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toughtoaster

toughtoaster

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Same ...

"Port injection will be used for cold starts and low loads whereas the direct injection system will take over once the engine has reached operating temperature or is under high load."

https://www.americantrucks.com/f150-direct-injection-engine.html
Thank you this is pretty informative. I found this quote particularly relevant:

"Because the fuel is no longer entering past the intake valve, the fuel cannot act as a cleaning agent (as it does with port injection). Thus, some early model EcoBoosts experienced idling problems as carbon built up on the intake valve, most noticeable upon a cold start (where the very rich mixture needed for a cold start would wash down the cylinder walls, decreasing burn efficiency and increasing emissions and carbon buildup). Once the engines were brought to operating temperature, the problem would disappear, and thus made it very baffling for many owners."

So the real issue with DI is upon start up when things aren't up to temperature that causes the gumming up of the intake valves.
 

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It's interesting, I was talking to a power train engineer last weekend and he was explaining the problems with DI/Cold start related to emissions. His explanation was above my technical knowledge, but he was investigating if the DI cold start cycle was causing some if the oil/fuel dilution issues (effectively going way too rich, before the cylinders are "sealed" by heat expansion). Thanks for sharing, always good to have more technical understanding!
 

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It's interesting, I was talking to a power train engineer last weekend and he was explaining the problems with DI/Cold start related to emissions. His explanation was above my technical knowledge, but he was investigating if the DI cold start cycle was causing some if the oil/fuel dilution issues (effectively going way too rich, before the cylinders are "sealed" by heat expansion). Thanks for sharing, always good to have more technical understanding!
According to Ford (as report in Car and Driver on eh 2.7 engine) the Port Injection system is active at low RPM and low loads. As RPM increases mapping moves across to a blend of Port and Direct injection but the Port Injection always has about 10 - 15% of the fuel supply
 
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