Well i just bought a 91gt and when i go full throttle on it, at around 3500 rpms it will start surging, as if the engine isnt getting enough gas, and it wont go passed about 4k. I just got a tune up, changed the oil filter, oil, plugs, wires, but im still having the problem, any idea to what might cause this?

 

mine does that randomly through the RPM range when floored. fuel pump is bad.

 

http://www.aa1car.com/library/2003/us80312.htm

 

check the easy stuff first like fuel pressure and try to replace the filter to see if that helps.

 

Fuel pump is prolly gettin weak or if you are lucky a filter needs changed.....most likey items at any rate. Runs fine @ lower rpms/power settings right?

 

check fuel pressure at different rpms
check timing

 

dotn for get to check you plug wires one might have came loose, check you FP or install an AFPR and gauge, clean the injectors also

 

im gonna find a mech and have them check to see if the fuel pump is working today. Anyone know how much a fuel pump should cost+labor?