A friend replaced the timing chain for me. As the pics in Hanes manual all had dual diferent colored links and the chain being installed only had 1 the timing was out by a cog. Caused a tapping/metalic rapping noise. Otherwise ran fine. Recently had time to open up the front end again and redo timing chain. Metalic rapping noise is gone but now truck idles extremely rough and stumbles and misses,bogs when I try to accelerate. Bogging sound is very intense in maf sensor. Replaced original as it failed diagnostics. Unfortunately no change in how it runs. When first fired up it took a lot of cranking before popping,farting and stumbling to life. Since then it fires right away but runs rough and so on as described above . Any help appreciated

 

Engines shouldn’t make metallic tapping noises. I’m betting you’ve got a bent valve or something that was making by until you fixed it and now it’s exposing the damage.

 

Timing set ok with jumper wire? Is the hold down bolt for the distributer pretty much in the center of the slot?