Multiple Misfire?

[Bunky]

I have a 2001 2500HD 6.0 gas,   it sat for a year or so.  Now I have multiple miss fire code.     I hooked up my scanner and it's Showing Cylinders 1,6,8 are missing firing.  They appear to be working on idle.  

 

The plugs and wires were new when I parked it..   

 

Any suggestions where to start with this ?

 

 

[vucelick]

Check for rodent-chewed wires.

[CamGTP]

Could be clogged fuel injectors too. Fuel doesn't like to sit for a long time.

[Bunky]

I looked for chewed wires because I have rad of several cases of this happening...but will continue to look...

 

I wondered about the injectors,   this is what happened to the last motor, it sat and I bought some rebuilt injectors and one was defective and it filled my my cylinder with gas and hydrolocked the engine and I hit the key and snapped the rod into pieces.   

 

So I have been running some sea foam my gas hoping to clear them up 

[Grubbworm]

Have you found the cause of your misfire?

[Bunky]

No I haven't really messed with the truck it's not my current daily driver..

 

On another topic I have always used sea foam for cleaning gummed up fuels systems (Mainly Carburetor)with good success..

 

Is there a better additive to use for fuel injection systems?

[txab]

Chevron Techron Complete Fuel System cleaner

[diyer2]

My choice.

[mattchrz]

Mr injector tests and cleans injectors and I replaced the coils and wires, all good! 05 silverado 2500hd 6.0 100k

Edited November 7, 2023 by mattchrz
Forgot to add my truck