If you recently have replaced the Air Intake Manifold Valley Gasket and are getting a Misfire (Cylinder 6 in my case) and Low/ Empty fuel code (P1319) this may be your problem.
It all started with replacing the headgasket on my 2003 Land Rover Discovery 4.6L 101k miles. I decided to purchase from Lucky8 Land Rover (a very reputable company) the complete Headgasket kit that came with everything. Headbolts, gaskets, and seals. I took my time on the whole job and made sure everything was to spec and torque. Upon it's completion, I turned it on, and the Service Engine Light was flashing. I read the codes and I was getting a fuel code along with a misfire.
It was definitely not spark related, I just installed new wires and Spark plugs, also my Spark Plug tester showed it was working, so not spark related, maybe fuel...
Thinking I clogged the injectors with some poopy tape I used to seal the inlet connection, I went online and purchased, new injectors. No change. Same misfire.
Well here's the dreaded test... Compression test, Passenger side was pumping 65psi (its low, but that's just idle) then i got to the problematic Misfire (Cylinder 6), 0-psi on Cylinder 6. Dang that means either warped head, bad valves or even worse, bad Piston rings.
Took the Head off and took it to the machine shop, the head passed inspection along with valves with flying colors. IT CANT BE RINGS!?!?!?! And on just 1 cylinder with 100k miles?!!?!?!
Sobbing back home from the machine shop I looked at the wretched cylinder once more and... EUREKA!!! the problem... the Intake Manifold Valley Gasket was missing a hole, the hole that Pushed fuel and Air into the Chamber (view Picture). It was a Manufacture Defect. Which explains the fuel code as well. How could I miss it??? Maybe because I finished it at 3am? Lucky8 sent me the kit for free again after I complained, replaced the parts and this car couldn't have sounded any better. Side note, I lapped the valves and replaced the Valve Stems when I had the Passenger Head off which makes feel a little better after this ordeal.
Hope this helps anyone or maybe the 1 in a Million guy who runs into this problem. Any questions please ask.
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