Rough running

[Billy Mild]

Let me preface this post with the dilemma I'm in, daily driver Jeep CRD is out of commission due to a trusted out diesel tank, 2 motorcycles are out of service 1 with a seized engine and the other cosmetic issues, and now the Vette has decided to run a little rough.

On the highway the ZR1 seemed to almost fight against itself, but if I go full throttle the Lt5 pulls just fine. The car would buck or almost feel like it was going to die but if I have the car more throttle it would pull without hesitation.

It is happening at low rpm sub 3000 RPM. Something that I also noticed is that the speedo quits working randomly.

Could this be a fuel pump problem? Spark plug issue?

Fuel injectors, coil packs, and wires have been replaced in the last 2 years. I have SW headers and new O2 sensors with a Marc Haibeck tuned chip.

Sent from my Nexus 6 using ZR-1 Net Registry mobile app