2013 rock warrior 5.7 flex, idles fine but stalls when given gas. need help

the truck stalled and died about a week ago, and wouldn't start. got it towed. the next day after work ( truck sat for about 20 hours) started the truck and it ran fine, except when i floored it and the tack hit 3k rpm the truck would stall, if i kept it under 3k it would run great. 2 days ago after driving about 30 miles the truck started to stall out and ran really rough, hooked to a friends computer and was getting a miss fire on cylinder 2,4, and 8. but if I let off the gas and gently pushed the peddle it would go. so I changed out the MAF sensor, same issue. yesterday I changed out all the spark plugs, let the truck idel for about 40 min, and it idled perfect. but when i gave it gas and took it for a test ride, it stalled and would barely move. when i put it back in park it idled perfect, gave it gas and at 2k the engine stalls. any help will be greatly appreciated.

 

Welcome aboard from The Pacific South West.

 

lots of factors causing it to stall - Bad Gas, Bad Plugs, Bad Coils, Bad Fuel Filter, etc.

When you replaced the MAF and Plugs, did you try reading the codes again?
Try to read the codes again, if its still misfiring on cylinder 2,4 and 8, the coils must be bad. Try moving the coils around and see if the codes will follow (move coils 2|4|8 to 5|6|7 then check if the codes will follow).
Good Luck Troubleshooting it and hopefully you get it fixed. Cheers...

 

the coils all looked ok. but will swap them around.

 

Changed out the coils 1,2,4,8 still stalling. Could it be the fuel pump

 

If it’s the fuel pump do I need to replace it with a flex fuel pump or can I use a standard gas one

 

Get an app like Torque for your phone and a bluetooth OBD2 adapter. With it you can see the sensors. The one I would be looking at first would be the throttle position sensor (I think they still have them but it's most likely part of the throttle body) and the gas pedal. They both should be just variable resistors and if they have a dead spot the computer will adjust the fuel incorrectly which could cause the motor to stall. If they are completely gone I think the computer will throw a code but if one is only sort of working the engine may stall before the computer has time to register it being faulty.

 

Hooked up and getting 2 codes
P0171 and p0174. Any thoughts? I have replaced all 8 spark plugs and all 8 coil packs

 

Have you poked and wiggled around for vacuum leaks?

 

Yes, no air leaks

 

Got some info that some one may have put something in my gas tank. Is there a fuel filter in the tank with the fuel pump? Can I change the fuel filter or do I need to change the whole pump?

 

Well sugar in the tank is the issue. Now looking for a fuel pump, very difficult to find. Thanks for all your help.

 

Ooof, brutal.

 

Who did you piss off?

 

https://www.youtube.com/watch?v=tRM-n15tuXs

You can look up the TSB on the fuel pump and flex fuels, some were faulty, but I can't remember what years.... You can get lucky and be one of the impacted ones and get a free pump...