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2011 QX56 Infiniti 5.6L
Fuel trims -10 to -16 under no load
on Cruise at 50mpg fuel trims -6 or so both banks
Exhaust smells of fuel when stopped
Injectors difficult to get to need to remove the intake manifold.
Once in a while I get 1 miss fire on one cylinder or another but not common
All plugs are new
Low pressure fuel pump is new
Overnight the fuel pressure drops and I must wait in the morning for pressure to build up with key on before start otherwise a P0087
What are you going to the injectors for right now? What's labor time on that? Might be cheaper to have a shop hook a scope up to it if you don't have one.
There's so many tests you can do these days without having to remove the complicated myriad of things to get below the manifolds. I'd explore other options.
pull off the vacuum hose that goes to the fuel pressure regulator and see if its wet inside/ smells of fuel, if you have a torn regulator diaphragm you might be leaking fuel into the intake via the vacuum hose.
Also, did this problem start before or after the fuel pump was replaced?
Problem was there before I replaced the low pressure fuel pump in the tank.
This pump is not connected to a vacuum as the pressure goes above 600psi sometimes according to the scanner.
The actual pressure is almost always different then the commended pressure by the pcu sometimes 60psi higher sometimes lower, which leads me to believe it might be the pressure switch its located right at the end of the fuel rail and electrical only.
I was told today the part cleared custom ill be picking it up tomorrow. Keeping my fingers crossed that its the right part.
