Checked WOT fuel pressure for 1st time this past weekend.
Alarmed to find that it dropped to 36,37,38 PSI from start through 3rd gear. Cruising at 30-40mph I floored it. Car dropped into 2nd and an astonishing 32 psi is what is registered, which held steady until I let off accelerator.

Holley AFPR is set at ~45 psi with vacuum disconnected. It also varies somewhat (~2 psi) up and down when setting it. Kind of odd. Additionally car will lose all fuel pressure in ~30 minutes after shut down.

I realize that this could be because of a weak fuel pump (which I will be replacing soon), a malfunctioning AFPR, or maybe a leak in a fuel line. I will be checking, fixing, or replacing all of those issues soon.

Questions Are: How bad is it on the engine to WOT the car under these poor fuel pressure conditions? What kind of safety factors are built into the programming? I don't burn my own chips, so my knowledge there is limited. My best 1/8th mile times were 8.9 at 77. I did a couple of mods, fixed one fuel leak. Next time at track (past weekend) I ran good times 9.03,9.11,9.12 with slightly worse 60' times. Miles per hour was low 76 and 75. Just seemed to lack it on top where it had before. Temperature was 40...traction not much of a problem. Hoping for better times on such a nice night. New mods were underdrive crank and no air filter, and playing with fuel pressure...which I find out the next day was hopeless. I'm thinking I could have pulled better times if fuel pressure was normal...but I don't know that for sure since I don't know what computer is doing.

Appreciate any comments

 

IMO, the computer is rich at WOT. Very rich. So you should be OK. 32 is getting low though! It might run lean and knock thus pulling timing and slowing you.

 

Try replacing the fuel filter first.

 

Hypertech chip...for what that's worth. Don't know how it reflects handles knock retard or anything else for that matter.

Fuel filter replaced last week when I did the crank pulley mod and fuel leak fix. Done before these fuel pressure tests.

I wasn't asking what causes the problem, anyway. Just...how dangerous is it driving this way, and doing WOT runs this way. Is 32 psi at WOT good enough? How much actual flow is that? How low is too low? I may want to wait a month or longer (a year ) before replacing parts.

BTW...could a brand new fuel filter be bad? Wouldn't usually consider that.