99 c7500 top kick with the 7.4L vortec. This truck was brought to me to try and fix it. The owner had already replaced injectors, fuel pump, fuel filter and fuel pressure regulator. The truck is running extremely rich and smells like fuel when cranking. I went through and checked over the owners work and found nothing obviously wrong. I read the data streams on my Matco scan tool nothing stood out to me. I checked every coil and threw new plugs in it as most were in poor shape from running so rich. Only code I have is for the oil pressure gauge.

 

does it start at all or just cranks? i know you said its running extremely rich but i just want to make sure its actually starting.

 

Yes it starts. Sometimes it takes quite a bit and usually backfires a couple times before it fires up.

 

what im wondering is if the crank position sense or screwing up or maybe the camshaft position sensor. how are the reading on the live data?