Faster at half throttle!?!?!?

[stss96]

My car is faster at about half throttle, if i floor it, it seems to just not want to go, like something is holding it back. any ideas?

 

[KEVINS]

List all of your mods to the car so we can help..

ks

 

[stss96]

just an air filter and maf pipe are the only mods. i replaced all vacuum lines, fuel filter, spring cleaning.

 

[Black1986Beast]

Maybe the settings of the Throttle Position Sensor are off??
Just a hunch..probably wrong

 

[TurboRegal84]

How old, and how many miles are on your Valve Springs?

 

[S10xGN]

Also, make sure your boost line is still connected to the top of the fuel pressure regulator. Mine blew off once and the car would lay over bad after half throttle...

 

[BlackBeauty]

Originally posted by stss96
My car is faster at about half throttle, if i floor it, it seems to just not want to go, like something is holding it back. any ideas?

If your motor is knocking at WOT, the ECM could be retarding the timing, making you slower. It is less likely to knock at less than WOT (unless you have a bad EGR valve like I did).

 

[stss96]

I set my tps but its messed up. i got it to .42 at idle but its only 4.00 at wot. I cranked the sensor all the way over at wot and only got like 4.45 volts. maybe i need a new sensor???

 

[BoostKillsStres]

Just take the tps sensor off and take a file to the outside edges of the curved ears. You don't have to remove a whole lot. This will give you more room on the bottom and top of the tps scale for adjustment and it only takes abont 10 minutes.

 

[UNGN]

My guess is you need a fuel pump. This is very common. Fuel pump can supply enough fuel for part throttle, but cannot for full throttle.

 

[BlackBeauty]

Let me just add that I feel the same way, about my car being faster at part-throttle compared to WOT, I felt that way with my Mr2 turbo as well as my current car. Maybe it's just feeling the increase in power as you accelerate, you are going from 0 boost to 15+psi, which is a large power increase. Compared to WOT once you reach full boost, then it's just acceleration at a steady 15psi.

 

[stss96]

Think i have found the problem, i dropped the tank to put in a new fuel pump (walbro 340) and the fuel sock was collapsed and in a petrified state. looked like the pump was trying to suck it up. thanks for the help.