something is wrong with my 5.0

[spdpilot]

my car is missing when its idleing, i dont know what it is? i already installed a new cap, rotor, coil, wires, i changed the spark plugs to but it is still missing, and smells like gas, seems like its running rich but i dont know why? and i feel a loss of power, it used to be faster.

As flustrating as it is..... you should take a step back and try to run down one issue at a time.

First, to me....from your quote above, I would start with the ignition items you just replaced. Just because they are new, doesn't mean they are all good.

Power loss, possible overheating, pinging or rattling noise, rough idle.... To me all leads back to the ignition parts you replaced. Or maybe timing. I would double check all your wires and check your timing. Pull the plugs and see how they are running. Pull your cap and rotor and see if any contacts are burnt from not being aligned. Also double check the gap on the plugs. If everything checks out there, you might want to toss some of the old parts on "one by one" to see if the rough idle goes away. When you replace parts and your car starts having problems..... it many times leads back to those parts.

Then move on to other things.

 

[beejay31000]

no iam thinking of buying one to see if it would help me burn my fuel better, because i can smell alot unburnt gas. should i buy a msd 6a box or not?
please answer.

if your car is near stock and its running like this, MSD will not help you. until you need some serious spark to burn fuel, the stock box will work. im still running a stock one on mine with no prob. like everyone has told you, check the small things before you waste a bunch of money. i bet timing is a big one....make sure you pull the little cap before you check it tho.

 

[Mustangcwo]

The 6A does assist in increasing spark and adding efficiency to the motor, however it will not solve your problem. You need to pull down the codes and fix what is wrong with the car. If you add parts or tune the car in the current condition, it will only mask your problems and eventually make things much worse.

Get the codes.
Fix the car
Then improve

 

[TEXSSP91]

put a vacume gauge up to the motor and if its 17 steady needle then wipe your fore headif its not .. then you have real problems and you can go form there .... then start rebuilding a 351 w ..lol