fuel pressure question

[nathan_spindler55]

hopefully someone can answer this. my buddy has a walbro 400 with stock hard line and fuel lab filter and then -6an lines after that, and when i turn the pump on with link i set the aeromotive regulator to about 45 psi. i know base should be 43.5 but it seemed like i had to adjust the regulator pretty far out to get it to that so i called it good at 45. then when we started the car it was running like 60 psi. shouldnt it stay the same as when i activated it with link? he also has it rewired and the pump runs fine.

think i found my answer... when i activated the pump in link with the car off the battery was only at 11 volts and with the car running it was at a steady 14v so the increase in voltage is why the pressure was higher. and im pretty sure that his pump is too much pressure for the stock hard lines. pretty sure thats why i couldn't bring the regulator down any further. someone feel free to correct me if i am wrong.

 

[jared98gst]

400 a big pump for all stock hardlines, if a legit aeromotive can't bring the pressure down lines are the problem

 

[nathan_spindler55]

its pretty much brand new aeromotive too. hes going to get bigger lines, even on the site when you buy the pump it says you need to modify your lines. so im almost certain he needs a bigger return line at the least to relieve the extra pressure.

 

[97_4g63t]

I'm running a 400 rewired with stock hard lines. I don't have any problem with fuel pressure.

 

[nathan_spindler55]

I'm running a 400 rewired with stock hard lines. I don't have any problem with fuel pressure.

what regulator you running? it seemed like the pressure didnt want to come down any more and his regulator didnt have much more room for adjustment. i will definitely try again though when he gets back.

 

[97_4g63t]

what regulator you running? it seemed like the pressure didnt want to come down any more and his regulator didnt have much more room for adjustment. i will definitely try again though when he gets back.

I'm running an aem. I do have aem fuel rail, and 6 an line from filter to rail and 6 an line from rail to afpr. I haven't had any issues at all. The return line isn't kinked or anything? Breather line is free?