my 1993dodge ram is backfiring and some plugs are not getting fire.no check engine light a mechanic said no codes are showing.i put a new distributer,cap,rotor,pugs,wires,coil, and fuel pump.it has 360 in it.i am leaning towards the pcm.

 

are you sure you didn't mess up the timing? that can have HUGE effects on running. too far advanced or retarded can do those things.

are you SURE the plug wires went where they belong? if they aren't firing then maybe you;ve got them firing on the wrong cylinder...

lots of variables and since you replaced so many things it could be any one of them.

 

the book says the timing is adjusted by the pcm.i removed the distributer and put it back where it was and then i took it to a mechanic.how can you tell when the pcm is bad

 

when the truck is running it will miss out and the air intake valve on back of the throttle body will start opening and closing making a loud hissing noise like sucking air and will die

 

hmm, sounds like either a plug wire in the wrong place or the timing is way off. trace every plug wire with the correct firing order and then do the timing, then come back with a report!

 

i did that a couple of times is there any other sensors that would go out and not throw a code

 

it just seems strange that something would go wrong that has nothing to do with the work you just finished.

vacuum line disconnected, or vacuum leak somewhere...

 

it was sitting for about 2months while i had the transfer case out.went to start it and this happened.

 

I am confused. Please explain "air intake valve on the back of the throttle body". For starters the 1993 360 didn't use a throttle body that I know of, they had the MPFI ( multi port fuel injection) system. The PCM does not adjust the timing, it controls the advance of the timing, but your base timing has to be mechanically set to the proper setting to start with. When you took it to the mechanic was it running OK when you got it back?

 

no it was runninglike this the mechanic still has it.he tells me it might be the pcm.