2016 silverado maybe electrical issues?

[jesse3]

so about 2 months ago my truck got repo and 5 days later i went and got it back. 3 days later and it wont start,switch the battery and nothing. it use to turn on with a jump but after 2 days it would not start w a jump. took it to a mechanic and they changed the following ( fuel pump. starter , fuel injector? and im not really sure what else bc my dad is keeping up w the mechanics but anywho they believe its an electrical problem. not a car specialist but they said they would pour gas down something and it would start but after you turn it off it doesn’t start. i don’t know what it could be or what not  any help? or advice?

[asilverblazer]

Sounds like a combination of dead battery and fuel delivery. Make sure the battery replacement or repossession hasn't interfered with the trucks theft deterrent system.

 

Also, might have an aftermarket 'device' somewhere on it causing problems too. (I've been surprised how many questionable devices I've found on different peoples cars... behind panels. Most were probably a tracking device that just had a positive and negative wire, but I would'nt doubt some have greater capabilities.)

 

[jesse3]

well we change the battery and alternator those were the first things we did and nothing but it wasn’t the first time i changed the battery i had already changed the battery and it worked perfectly without any problems 

[Snowcamo]

Look up under the dash and disconnect the aftermarket GPS locator from the ODB2 port. Then put it in the glove box. The dealership you got the truck from likely disabled your truck.

[asilverblazer]

2 hours ago, jesse3 said:

well we change the battery and alternator those were the first things we did and nothing but it wasn’t the first time i changed the battery i had already changed the battery and it worked perfectly without any problems 

 

11 hours ago, jesse3 said:

they said they would pour gas down something and it would start but after you turn it off it doesn’t start.

If the battery will crank the engine so that it can start by "pouring gas down something" then it isn't the battery. 

 

If it is only running until the gas that was poured down it is gone that means there is something preventing fuel delivery and I would suspect an immobilizer has been added. If it runs continuously after priming it by "pouring gas down something" then fuel pressure needs to be monitored. 

 

Which fuel pump was replaced? There are two, one in the fuel tank, a lower pressure pump and another on the engine, a high pressure pump. The low pressure pump may be disabled or defective and cannot prime the high pressure pump. 

[jesse3]

according to my dad both were replaced the one in the fuel tank ( under the bed ) and the one by the engine block? and they said still nothing they had already switched both of them couple weeks ago

[jesse3]

yes it still continues to run and drive after the gas is pour down “something” (i don’t what its called  ) but after you turn it off , it wont crank at all 

[jesse3]

He also said there isn’t enough fuel pressure some where and they can’t find the reason why? This $*** is complicated lol 

[asilverblazer]

I think you are confusing some terms or symptoms (no offense intended). It HAS to be cranking at some point for pouring gas in the intake to work.

 

If I am understanding this correct:

Walk up to the truck, pour gas in the intake, turn ignition key and the truck starts and runs fine.

 

Turn off the truck with the key and then try to restart it again and nothing happens...

 

[asilverblazer]

When you walk up to the truck and turn it on the low pressure pump should build pressure to about 60 psi. (Unless it has been disabled by a device)

 

The high pressure pump builds pressure over 500 psi.

[jesse3]

Yes that’s exactly what it’s doing. You pour it down and it starts. Then you turn it off , try to turn it on and it cranks but nothing 

[asilverblazer]

I would recommend looking for an immobilizer of some sort.

 

Near the OBD port or cigarette/12V ports.

[asilverblazer]

Just now, jesse3 said:

Yes that’s exactly what it’s doing. You pour it down and it starts. Then you turn it off , try to turn it on and it cranks but nothing 

But it IS cranking, that rules out battery. 

 

3 minutes ago, asilverblazer said:

the low pressure pump should build pressure to about 60 psi. (Unless it has been disabled by a device)

I would make sure the low pressure pump is getting power when it is supposed to, a simple test light on it should confirm it is getting power.

[jesse3]

Alright if you know Spanish this what he says “No le llega suficiente energia a los inyectores “ 

 according to apple translate lol it translates to this “The injectors don't get enough energy.” 

[asilverblazer]

If the injectors aren't firing then it wouldn't continue to run after dumping fuel in the intake.

50 minutes ago, asilverblazer said:

Walk up to the truck, pour gas in the intake, turn ignition key and the truck starts and runs fine.

 

In either case the only reason the injectors wouldn't be working is if they are disabled.

 

Check all fuses for good measure but you are still probably looking for an immobilizer.