So lately I have been have big a hard time starting my truck. When I go out to start the truck it just cranks and cranks, when it does start there is a puff of smoke from the tail pipe(assuming it’s the abundance of fuel being dumped into cylinders). When it cranks over it’s doing so at a normal rate. I do have a code p0335 for crank position sensor. I replaced the sensor twice first time was a crappy autozone one, truck started normal after replacing it. On my way to a doctors appointment my tach stopped working and the truck started to hesitate and the code came back. So I replaced with an ac delco sensor and did the relearn procedure. After that was done the tach started working and it started fine. Went to start the truck the next morning and low and behold the hard starting returned. I am at a loss any help would be greatly appreciated.

things I have done
- plugs and wires
- oil change
- oil pressure switch and new screen
​​​​- ac delco ckp sensor and relearn procedure
- has fuel pressure (when valve on rail is pushed the fuel with spray to the hood)
- checked all fuses (look good)
- battery and alternator tested good