Engine won't run

[DIYowner]

I have a 2013 Avalanche LS 5.3. My problem started about 2 weeks ago. I was driving normally and had a misfire. I took the truck to Autozone and we did a scan. It showed Codes P0307 Cylinder 7 Misfire Detected. It also showed secondary DTCs as P0174 Fuel Trim System Lean Bank 2 and P219A Fuel Trim Cylinder Balance Bank 1. Based on this I replaced the Coil on Cylinder 7. I also replaced the spark plugs and wires. When I pulled the spark plugs out the centers indicated that the engine had been running rich and not lean (dark insulators). The plugs had just over 9,000 miles on them and were installed by the dealer that I bought the truck from. After making the changes the engine will start, but won't rev cleanly or run for very long before stopping. Almost like it is running out of fuel. I've run an even mix of regular and E-85 fuel in it since I've owned it (just under a year). I am the second owner. Prior to the misfire it ran perfectly. My normal driving is about 70% stop and go and the balance at highway speeds. I don't currently have a scanner (mine died and I have ordered a new one, but it hasn't arrived yet). I started going through and just looking to see if I could find something obvious. I checked the fuse panel (engine compartment) and noticed that there is not fuse in position 20 (fuel pump) nor a fuel pump relay. My understanding is that these trucks have an in-tank fuel pump, but I would think that the pump circuit would be protected by a fuse. Any thoughts, suggestions, or guidance would be highly appreciated. For the past 20 years I've owned and driven Dodge Rams with diesel engines. This is the first computer managed gasoline engine truck that I've had.

 

[ToyHauler13]

I had to go check my 2013 fuse box. No fuel pump fuse or relay either.
We do have a fuse 21 FSCM (25A) that powers the Fuel Pump Control Module which controls the output of the fuel pump.
Other members will have more reliable guidance than me. I have had Rich Bank 1&2 codes causing a Check Engine Light a few times and it did not affect drivability at all like you are experiencing.
What is your current milage on your truck?

 

[DIYowner]

Thank you for the feedback. I also have a 25A fuse in slot 21 FSCM. My truck has a little over 155K on it. This is driving me nuts. I've been maintaining my own vehicles for almost 50 years and I've never had anything that is this challenging. I can tune a normally aspirated racing engine without any difficulty. I've got a new scanner on the way, but it won't be here for several days.

 

[ToyHauler13]

Same here as far as maintaining my past vehicles. It's not getting any easier to repair problems with EVERYTHING on these newer vehicles controlled by some control module.
When I changed my spark plugs (looked to be original) around 100K they were just what you wanted to see when reading a plug and super clean.
Your new scan tool will help a lot. Clear those codes now that you know what they are and see what sets again.
Maybe look at the live data for fuel pressure first since you're suspecting a possible fuel issue before digging into the mixture issue.
Have you checked for a large vacuum leak? Brake booster vacuum hose or the PCV line that goes to the back of Bank 1 valve cover.

And if someone hasn't yet, disable the AFM feature that deactivates four cylinders under light load. That scan tool should be able to do that.
Good luck!

 

[ygmn]

Check fuses with Ohm Meter.

Also check fuel pressure.

What is interesting is you have misfire #7.
Could be AFM crap or intake leak by #7.
BAd #7 Fuel injector

You need to confirm when new code reader arrives.