Hesitation, misfire no codes?!

[sspeedguy]

Hi,

I have an interesting one here,

I have done around 1000 miles since my new stg1 cam install and all has been very good. Around a week or so ago noticed it was a bit down on power and seemed to be hesitating when cruising at around 1500 rpm and when I put my foot down to accelerate. This steadily seemed to get worse a and last week while overtaking a dump truck it really held back on me and I got a flashing cel which went out after a few seconds. I checked this later and found stored p0300 misfire code. 

I was thinking fuel pressure as I recently did the pump assembly but I checked it and it's spot on 58 psi at all times. I'm a bit stumped...

This truck has new cam/ lifters, plugs, fuel pump+pressure reg, oil pump, timing chain and full service. All done at the same time. Any ideas??

I am still thinking fuel/air as it will idle fine but as soon as you blip the throttle it misses and is now not really drivable... But it has thrown no codes!

Edited October 24, 2021 by sspeedguy

[shakenfake]

Do you have hptuners? I highly suggest investing in it as it will help you pinpoint your issues.

[sspeedguy]

I don't yet no, it might be an idea though. It needs a good scan tool to see what's misbehaving when throttle is applied. It's so weird cuz I would expect a code but there's nothing..