Alot of sputtering and back firing

[smoove mood]

My 87 has been sitting for abt 6mo's I changed the starter and ignition module. Added premium 91 octane and some fuel booster. I finally got it to crank but the idle is very rough and there is a motor sputtering and back firing happening. Ive let it run for abt 40 min but i dont want to damage it. What should I do?

 

[87 national]

crank sensor

Make sure it is not rubbing on the ring.

 

[buickruss]

Also check your MAF numbers

 

[OneBadTT]

You may want to change the fuel filter.

 

[smoove mood]

Now that you mention the fuel filter i was hearing a burst like gushing nose coming from the left side.

 

[ALVAROG1983]

Check your maf might of gone west also check your coil pack,fuel pres.