So a couple of months ago my 4age aw11 was running on top the world. Then oneday I disconnected the t-vis and noticed this massive flat spot between 3000-4000rpm. I played with the cam timing but it didn't go away at all.

So I started looking in other areas. Specifically fuel systems after a hint. I replaced the fuel filter and the car started idling rough really rough. Almost like its missing. Then I put the old filter back on yesteeday it ran fin initially. Started it this morning and its really rough again.

Now she actually won't start at all. She just cranks over and over.

So I check connected the fp b+ the pump is running but the return hose is not getting an overly feeling of pressue. I gave it a quick squeeze and the pump shut off.

Last week while idling it started normally but after a few seconds had a rough burble but drove ok apart from the flat spot.

So what do you think. Does it sound like it could be the fuel pump? Do they normally cutout if you give the return line a quick squeeze?

Dodgy fuel pressure regulator?

any ways I can eliminate the FPR without a guage?
 
one website say squish the return line if the car then starts it means bad FPR not giving enough pressure

I just googled how to check FPR and one method I saw was to replace the vac line with some clear tubing to see if fuel is leaking into it (meaning ruptured diaphram)