I have an 03 rcsb silverado with the 5.3 in it. I just put a Harris Speed Works Sudden Impact Wet system on it. After spraying a 100 shot on it a few passes I decided to pull alittle more timing and go with the 125 jet. The first part of the pull was awesome I felt a difference in the jetting, but about 3 seconds into the pull the truck fell on its face and the check engine light came on. The code was p0300 random missfire so I know it was detonating. I think I shut it down before any damage was done. I haven't pulled a plug to see yet. The question is did the fuel pump reach its maxxium capibility? I have a pretty new fuel filter on it. The truck does have 67k miles on it and as far as I know its the stock pump. Any advice would be great. I am switching back to the 100 pill for now.

 

first,
what all you have done to the truck?

your fuel pump is probably not maxed out.
you need to log your injector duty cycle and go from there.

 

A flowmaster cat back, a tune using HPtuners and the Nitrous.

 

It just happened last night so I haven't had a chance to datalog anything yet I realy need to know what my a/f ratio is though when it happens .

 

did you change the plugs to tr6's or stock plugs cause mine did this once and my #7 plug was burnt off.

 

What are the limits of the stock pump?

 

yes I have tr6's gapped to .035

 

That is what I am trying to find out. This whole thing has me nervous about using my nitrous. I think that it is the pump because it pulls fine for a few seconds then acts like something is holding it back, and it continues to get worse the longer I'm in it. I wish I had a fuel pressure gauge to see if the pressure drops off or not.

 

I use a hsw plate system and spray a 150 shot on my 5.3 with stock fuel pump.

 

I pulled a P0300 code when I had low bottle pressure. It would run rough, and felt it felt like it wasn't making much power. I have a bottle heater now, and I haven't got that code since. Are you sure you are detonating? I detonated one time and I could hear it knock when I sprayed in 2nd gear at 2500 rpm, it sounded like a diesel. It spun bad in first, and I let off the throttle, when I got back into it, it had already shifted into second gear, the rpms dropped to 2500 and when I sprayed, it knocked bad. Haven't done that since.