The following items are new: all new motor, new carb/new holley electric pump/new regulator/all new fuel lines 3/8/new gas tank/new sending unit/new sock,new gas cap vented, I also vented the tank. When cold the gas pressure gauge reads 6lbs, when it heats up it drops to 3. This is the 5th fuel pump, my only other options I can think of is to change the fuel pressure gauge or change the regulator to allow a return line. Any ideas, this has been going on for months and nobody has been able to figure it out?

I would disconnect the line from the carb and tank. Block the end of the line at the tank then put an adapter to be able to add air pressure to the line from the tank to the carb. Something with a gauge and it needs to be able to hold pressure. Pump it up to 6 lbs and see if it leaks down. After trying that and if it still leaks down. ,at each joint, connection, regulator etc, track back until the system holds pressure. You will then find the weak point.

Kev

Also check to see if needle/seats too high or leaking. Or even a bad guage. I had lots of these, jegs, russell, summit, liquid filled. Pump bypassing?
I did loose a pump lobe.

Do you think it is possible to be loosing voltage to the pump?

Damn, you guys are killing me, LOL. It's "LOSE", as in "losing fuel pressure", not "LOOSE"......................

Lemme ask; does the car act as though it's running lean at WOT?????? Have you had it on a chassis dyno to check performance and A/F ratios?

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After changing fuel pump and regulator, creating a return line it was still doing it. Called holley tech line, turns out liguid filled pressure gauges under engine heat act like my symtems. Replaced with non liquid filled, couple hundred dollars later turns out a 15 dollar gauge is the problem. All my toughest lessons are learned monetarily.

After changing fuel pump and regulator, creating a return line it was still doing it. Called holley tech line, turns out liguid filled pressure gauges under engine heat act like my symtems. Replaced with non liquid filled, couple hundred dollars later turns out a 15 dollar gauge is the problem. All my toughest lessons are learned monetarily.
Sorry I came with my reply a little too late, but those liquid filled gauges are tricky. I'm still using mine, but needed to bleed some air pressure from it, a couple of times, before the darn gauge stopped doing that. Seems like if the emvironment pressure is different where they are manufactured, than where one uses it, and it needs to equalize the pressure inside the gauge with the outside pressure. Mine is working perfectly for a couple of years now after this procedure. Yours got to have a little rubber plug, that's what I use to bleed air from it, when hot.

I had samne probelm with a liquid filled unit and went back to the mechanical.. So,ORENCH, how did u bled the pressure down to the level that worked?

I had samne probelm with a liquid filled unit and went back to the mechanical.. So,ORENCH, how did u bled the pressure down to the level that worked?
Thru the small rubber plug on top of the gauge. With a lot of technically advanced use of my "index" finger's nail.:D

I went through two Jegs liquid filled gauges with the same problem. I bought an electric one which works perfect. I will try bleeding off one of these liquid filled ones and see if I can get it to work.

You would think the manufactorers would say something about bleeding it down in the instructions as a maintenance issue or correcting it with a fluid that works?