was running fine parked it 20 mins later had to move it maybe 10 feet cranked and moved no problem 2 hrs later go to leave wont start has little backfire a few times messed with wires cause heard a frying sound inside distributor cap would start run fine a min r 2 then sputter out so bought wires replaced them still wouldnt really start it tried a few times and then heard loudest backfire ever and found muffler busted open at seam pipes inside it twisted (it had been parked for bout 3 years b4 replacing fuel pump and we have dirt dubbers bad here my theory maybe nest inside broke lose and stopped up the exhaust but idk) and also when turning key the fuel pump doesnt kick on every time had same problem when first replaced pump and had lose connection in wires and was hard to start at first after fix would act like old 70's cold nature ford for first few mins then run fine..... im thinking replace distributor cap and rotary button and maybe check connections on fuel pump any sugestions would be greatly appreciated

 

For sure the distributor cap & rotor get replaced. Then I'd check & make sure the coil is hooked up properly. I had an '80 Sierra Grande 4x4 that had the exhaust explode just like yours. It sounded like a shotgun on your shoulder & unlike you i didn't find the muffler or even parts of it lol. Turned out to be the HEI ignition (coil) that was FUBAR & causing it to fire randomly. So when cranking it over & over all that did was fill the exhaust with gas & when it DID finally fire = BOOM!

Something is causing misfiring so start with the dist cap & rotor & you already have the wires.
I'd also do a search in here for "cleaning an EGR" that could be plugged up as well.

 

but could get it to run for few mins then it would start sputtering and shut down ive been driving it 4 a month now since put fuel pump in and it messed up had short in wires after getting fuel pump to start back working again it started being a pain to get started when it was cold like it started doing yesterday first time it did this it never blowed the muffler wide open and it just started cranking fine prob id say maybe 5th time of having a hard time cranking it so was thinking maybe to do with fuel line wires causing this cause fuel pump not kicking in every time i turn key

 

If your 'check engine' light is on stop by AutoZone and get the OBD code(s) read, If there are any present let us know what they are.

 

not got it running yet i stopped after it muffler exploded last night but fixing to go back to work on it some more also got to do something bout muffler busted wide open

 

i replaced fuel filter and its running like a champ now a really loud champ so now gotta fix muffler thanks for the help

 

Glad you got it fixed. One thing about no muffler you won't have any trouble hearing if it is running or not.