Hey fellas so I completed my LS swap on my Foxbody. But i'm having some sort of issue with the car. Havent had time till now. Car starts up fine and drives but at WOT I LOOSE POWER like something is holding it back RPM's go up fine but car just wont grab or pull like it should feel's like it wants to. Any ideas what could be the issue would be helpful. I dont want assume but here's a couple thing I have in mind.

1. Not enought fuel...i still have the stock 4cyl fuel pump with a corvetter FPR
2. maybe i need a tune, PCM was flash a deleted the vats
3. Trans could have a issue, fluid looks good, but ill check it again
4. torque management

Keep in mind that cars drives fine and shift fine had a guy check it with hptuners and said gears went in all fine.

What can be the issue?

 

tttt...

 

If the car lays over on the upper end of the rpm range, It is usually fuel related. A factory fuel pump is rated at 56psi and 23gph/88lph(new). your ls should have 58psi. You could tune it to run with this, but you won't have the performance you should out of the engine. The correct thing to do is upgrade fuel pump. Even though the 5.0 had the same pump, it was barely enough to support its 225 hp.

 

A wideband would be very helpful. I'm going to guess fuel though.

 

thxs, yes my psi is at 58. tonigh ill record my fuel pressure gauge if its constantly at 58 or above... hoping this could determent if the fuel is the issue.