for the past few days my lo3 has very little power below 2000 rpm but from there up till red line and beyond it pulls like crazy up till 6000 or so just before it starts falling on its face but only if i hold it in gear

spins the tires going into 2nd but from a dead stop it wont spin

it used to be more balanced less top end with more bottom end

is there a sensor that could cause this

apperently i had the idle air set far to low and the iac was over compensateing for it
it was causting a small bog from a stop

 

What color are your Spark plugs?

 

Bosch Platinum plus and they all look normal other then # 5 but it has the bad valve seals so its a bit darker then the rest but other then that all is normal now
just if i hold it in 1st or 2nd it keeps pulling hard till 6000 or so then it starts to let the nose of the car down like its lost power
but from idle till 2000 rpm it dosnt have much like i said in an earlier post

it wont spin off the line but will kick the tail out going into 2nd

the engine is stock heads stock cam stock tbi is stock open element boosted fuel pressure and timing at 4 advanced

i would have never found out had i not been bold and left it in 1st and shifted it to 2nd


and no the tach is not off ive checked it with the tach from my engine tune up kit

when in drive the car shifts around 4800-5000 from 1st to 2nd and right around the same for 2nd to 3rd i just had noticed that the car really seems to pull hard at 5000 and like its shifting to early so i tried holding it and it seems like really my read line should be 6000 and not 5000
any one elses tbi 305 like this

 

You're not really making any power above 4500 rpm, the cam that is in your motor is one of the smallest GM ever produced. The max you should ever NEED to rev a LO3 is about 5000 to 5250 and thats pushing it.

The reason that it's spinning into second is that you are already out of the power band and are droping back down into the power band when you shift. This is hard to swallow I know as we all want tire burning shifts, but I've proven it to my self time and time again at the drag strip. If I shifted at 5700 instead of 6000 rpm I was about a tenth quicker and it did not chirp the tires on the shift. Keep in mind I'm running a cam about 5 steps bigger than the stock LO3 and I'm shifting at 5700.

 

I have a L05 with L03 everything hooked on. I Lock the Torque Convertor by using a switch i hooked up. Theres an Artical around here somewhere.. And its sorta Gutless in the begining but when you get up there in the RPM's its Pulling hard, and then when it shifts it feels like the rear end is gonna come out from underneath the car and pass it.

Maybe he's got a TC problem.?.?.?.