2015 Ford F250 super duty xl 6.21 flex fuel
December 19th filled up with gas for two hour trip to memphis...got to Memphis stopped for drinks...started and truck wanted to die, was missing...made it to auto zone and scsnned...miss fires on multiple cylinders, system lean. Was able to make it back home...parked the truck while waiting on 8 spark plugs and wires to come....changed them...it didn't want to run right after changing until I kept clearing the codes....then after 3 weeks it started doing the same thing then idled down and died...had it towed home...sat for a bit while I tried to figure out what was wrong...figured it might have been two of the plugs went bad because of pb blaster used to get them out...changed them and got it to run...drove it for a few miles to see if I could burn out any residual pb blaster, was running ok....came home let it idle then it idled down and died, wouldn't run again after....that's when i found about the other 8 plugs under the coil packs....I changed them, the coil packs, the
Back two o2 sensors after cutting the cats off and seeing they were clean...welded them back on...and it would start and idle then die....fuel pump was showing 13psi versus 89psi so changed the fuel pump, vapor canister, and vapor purge valve...still would start then idle down....from research it said to check the fuel pump driver module....changed that and then it would start and idle down and die pretty quick....took my old battery off and connected the battery wires to drain the computer, and then bought a new battery today....the truck has the start assist so you just barely have to turn the key. Now it just cranks and cranks but won't even turn over to start...I'm lost...I've checked the fuel pump relay also. I'm nit sure if there are other fuses or relays I need to check or where to go from here....please help
Please include your mileage in your vehicle description. What was the code given at AutoZone? Note that throwing new parts at a problem often only complicates finding the issue that your trying to resolve. Did any of the parts you replaced test bad and were the replacement parts OEM or aftermarket? It sounds like your truck may have a fuel delivery problem so changing coil packs would have no effect on that. Our FAQ has a excellent section on "Crank but no start"
Here's an example of why with this kind of problem it's generally a good idea to verify internal engine condition before firing off the parts cannon:
