2018 low fuel pressure low side, misfire on cylinders 5,6.

[El Coyonosa]

Hey I'm hoping someone will be able to help me because I'm at my wits end with this problem. 2018 raptor, 102k. Driving the other day it started to misfire on all cylinders on Bank 2. I changed plugs, noticed its sending fuel down the exhaust and misfiring on 5 and 6. Codes its throwing are P008a, p0300, p0305, p0306, p0316, po453, P05B0, and p2418. I changed the in-tank fuel pump, the plugs are wet on 5, and 6. It has a long cranking time before starting, shudders and Rpms are around 1k while running and still sending fuel down the exhaust. I've checked the cataylic converters its not plugged, made sure there's no trash keeping the injectors stuck open. I'm frustrated and can't afford to take it to a dealership. Can someone please help?

 

[El Coyonosa]

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[FordTechOne]

Is P008A still setting? If so, focus on that, because the engine will never run properly with low base fuel pressure. Was power to the fuel pump tested and confirmed to be adequate before it was replaced?

With the misfires being reported on cylinders 5 and 6, it’s possible those injectors (high or low side) are hung open, which would cause both low base fuel pressure as well as fuel in the exhaust.

Start by removing the spark plugs on bank 2 and then turn the ignition on. Inspect cylinders 4, 5 and 6 for fuel leaks using a borescope.

If there is fuel leakage, remove the port injector rail and inspect for drips/leaks from the injectors when the key is turned on. Replace the leaking injectors as necessary.

If the port injectors aren’t leaking, that isolates the leak to the high side injectors. High side issues are often caused by contamination, so you’ll want to go through the entire high side system before spending money on replacement injectors.

 

[El Coyonosa]

I appreciate it, gdi motors are a new thing for me. The pump before replacement wasn't running and no psi confirmed before replacement. I appreciate the reply I'll let you know what I find out.

 

[El Coyonosa]

I've tested the low side injectors, ohms are
.02 across the board, my next question is how would I test the low side fuel pressure sensor on the rail? What should it read? Thannks in advance.

 

[FordTechOne]

I've tested the low side injectors, ohms are
.02 across the board, my next question is how would I test the low side fuel pressure sensor on the rail? What should it read? Thannks in advance.

The resistance check verifies the solenoids are electrically within spec, but not that they’re functioning properly mechanically.

You’ll want to monitor the FLP PID with ForScan or IDS to see low side fuel pressure. It should read approximately 77PSI key on engine off.

 

[El Coyonosa]

Appreciate the help sir. I can monitor the Flp with my tuner.

 

[El Coyonosa]

Update, sorry it took a while. I hate when a thread dies without the solution being posted. It turns out the #6 hp injector was OK but, #5 hp injector was bad, I went ahead and replaced all hp injectors. The misfire has gone away and it's running better than it has for awhile. I appreciate all the input and help from the members. Without you I'd probaly still be trying to figure it out. You are a great help to people who still like to work in their own stuff and people who refuse to pay the stealership to work on our own stuff. Ty again

 

[El Coyonosa]

Oh one other thing, so when the #5 hp injector was stuck open dumping fuel into the cylinder I gained probaly 1-2 quarts in the pan and smelled like gasoline. I changed the oil, and filter my question is should I be worried about that much getting past the rings? I'm assuming that's how it got there. Would this cause a loss of compression and is there anything I can do if something needs to be done? Ty in advance.

 

[FordTechOne]

Oh one other thing, so when the #5 hp injector was stuck open dumping fuel into the cylinder I gained probaly 1-2 quarts in the pan and smelled like gasoline. I changed the oil, and filter my question is should I be worried about that much getting past the rings? I'm assuming that's how it got there. Would this cause a loss of compression and is there anything I can do if something needs to be done? Ty in advance.

Fuel getting past the rings won’t cause low compression unless the cylinder wall/piston was damaged, which isn’t likely. You can check the cylinder with a bore scope through the spark plug hole.