A few months ago I put in a 3k gsk, rolled her out of the garage warmed her up then while it was in neutral, slammed my foot to the floor. RPMs went out of sight and it sounded like I was floating the valves. Unsure of what I just heard, to duplicate it I slowly increased the revs and at about 34-3500rpms it starts making that sound again and this time I noticed it was blowing white smoke. It wasnt until a week ago when I installed the 60lb valve springs. Thinking that this solved my problem, same scenario: backed her out of the garage, warmed her up, then BAM! Right to the floor with the throttle I go. And again, same thing. It seems like I'm starving the injection pump of fuel. When I bought the truck it came with Bosch 300s, intake, and 4" exh. And NO gauges. (They are in the process of being installed as we speak, so anyone asking about fuel pressure fluctuations, take note.)

Any suggestions?

 

Forgot the most important part!

98 12valve QCLB 4x4, 3k gsk, 60# springs, Bosch 300s, BHAF, 4" exh. Georend tranny

 

None of us can give you an educated guess until you report the fuel pressure then.

The stock lift pump, in good working order has supported north of 600 Hp though, doubt you are there yet.

 

Low timing will cause white smoke in the higher RPM's. Also, fuel combusts much better with boost. Put a load on it instead of free revving it, you won't get the popping and white smoke. My 12v will do the same thing.

 

Also, if you're running out of fuel by reving it in neutral, then you'd never make it into third gear when driving.... Sounds like timing to me. Like Tate said, it need a load...

 

Lots of times new power mods or GSKs will cause the little bit of additional torque on the injection pump needed to slip the gear and timing.
Makes you think you did something wrong doing your mods when it really comes down to the timing gear nut not being tight enough before you started.

 

Thanks guys. I might be able to get to it this weekend. I'll let y'all know.