i need some insight on what im doing wrong or overlooking. i have a 90 rs with a hsr'd 400 in place of the 305 tbi. when i did the swap i put a walbro 255 lph fuel pump in it. after about 8 mos the engine started to miss, spit, and sputter with any change in throttle after about a half an hour of driving. i checked the pressure and it wouldnt go any higher than 30 psi. so i removed and capped the return line to eliminate the regulator. it still wouldnt make it above 30 psi. so i changed the pump and the filter. the new pump made 43 psi, for about 6 months this time. the same syptoms came back. so i replaced the pump and filter aaagain. and here it is 6 months and a deployment to afghanistan later with the exact same problem. what am i doing wrong? is there something the tpi fuel system has that the tbi doesnt?

 

You might try just replacing the filter.

 

i'll try it. it cant hurt right? thanks