I have 95 f150 ext can long box with 302 5.0l. I have tried everything but can figure it out. Truck runs fine in park or nutral but every time it's in gear drive or revers the truck will back fire and buck I won't get over 25 and if it dose about every 4 seconds it will back fire. The truck as some upgrades like 30lb injectores afs heads long tube headers edlebroke intake manifold up graded fuel bump with steel beaded lines and mad ignition along with fuel regulator. I thought it could have been a bad mass airflow sensor so I ordered one from American muscle for a 95 mustang calibrated for 30lb injectores nothing changed any help would be apericated greatly seriously in need

 

Do you have cats on it ?

 

There is no cats just long tube headers to 3inch out the back

 

Check the distributor cap for cracks

 

The cap and rotor are new checked them any ways no cracks or anything

 

Gotta be a timing issue