12 valve won't rev right

[SSSDiesel]

On my 97 12 valve when I take of in third gear I can't get passed about 3300 to 3400 rpm's it kind of makes a weird noise like somethings holding it back. But when I'm in neutral and rev it, it will go to 4000 grand easy and it sounds fine. I've had the 4 k kit and twins for about a year and it's always been fine. It seems like it started doing this right after i installed lazer cut dv's and a cfm intake manifold. I can't figure this out!

 

[1QikDzl]

On my 97 12 valve when I take of in third gear I can't get passed about 3300 to 3400 rpm's it kind of makes a weird noise like somethings holding it back. But when I'm in neutral and rev it, it will go to 4000 grand easy and it sounds fine. I've had the 4 k kit and twins for about a year and it's always been fine. It seems like it started doing this right after i installed lazer cut dv's and a cfm intake manifold. I can't figure this out!

not sure what delivery valves your had prior to the lazercuts , but have heard of guys losing hp on the dyno and went back to 181's or 191's not sure? Maybe start there, and see what happens. Especially since it started acting up after you installed them. good luck

 

[BigYellowIron]

Do you have 60# valve springs? Sounds kinda like valve float due to boost under a load. That would explain why it dont do it in neutral. Just a thought???

Adam

 

[zstroken]

Check your fuel pressure.

 

[BigYellowIron]

Ok well it was early and your picture split you signature so I missed the rest of your mods. Do what zstroken said!!

 

[SSSDiesel]

I have 60lb valve springs and I have a pusher pump, I do not have a fuel pressure gauge I'll get one! Now I have an excuse to put another gauge in my truck.