Anyone with a built motor had a issue with the stock fuel lines being to restrictive (small)after installing an after market fuel pump? I'm having a problem keeping fuel pressure up above 5500rpm, everything else seems to check out. Or any suggestions on what else might be going on.

 

What do you have done to the motor? What fuel pump? What injectors? What rails? Have you checked your FPS? It is one of these things that is causing your problem not the lines, unless you have a 1500hp mustang.

 

svt focus pump , mmr fuel rails, 30#inj.had it on the dyno made a little over 320rwhp, messed with the timing a little did another pull and pressure just went to 18# at 5500. I don't recall us checking the fps so maybe. I was just thinking there could be to much restriction and that could create to much back pressure, just grabbin at straws.

 

You either got a bad fuel pump, your fps is not reading right (make sure the vacum line is hooked up) or you had a bad install on the fuel rails. My buddy had a mongoose kit installed at mph and they put in a bad fuel pump (brand new). It was cutting out on him in higher rpms. They went him a new pump and problem is fixed.

Are you NA? If so thats alot of injector for that hp.

 

Thanks - I will check that. Yeah for this pull.We havea 150 shot installedand have actually done one pull with it. Was burning the n/a tune when this issue came up had been fine until then