I've been trying to fix this for monthes. I was convinced it was a fuel boiling issue but the car died within 15 minutes of run time once when I had over 1/2 a tank so I know there is no way 10 gallons of fuel got hot enough to boil in less than 15 minutes. If I drive the car until it dies I can wait 40 minutes and ride it again. If I don't let it comepletely die and go back to it an hour later It won't make it 150 feet. Sometimes on hot days when I turn the key on the fuel pump makes a horrible noise (new pump and this happened when the car hadn't been moved for over 8 hours. Car has a new pump, filter, relay, ecm, alternator, battery, and all the ignition parts replaced. I have no codes and I am losing fuel pressure. Hot days it dies faster than others. I hold 45 unhooked 35 hooked and when it starts dieing it drops to 8psi and will only idle, then all of the sudden it will drop to 0. It never fails to start back immediately but i only get enough fuel pressure to idle roughly. What do you guys think could be my problem? Got another bad fuel pump? the previous owner had a Walbro with a pulsator and I"m running a delphi with a piece of hose now. Think I got a bad pump or possibly a faulty sending unit? Wires getting bad contact and kicking some kind of breaker in the pump? I'm about to carb this thing as bad as I hate to. Thanks

 

Whatever you do, DONT CARB IT!! Ive seen so many people do it only to regret it horribly for multiple reasons.

When you say "hooked", you mean the FPR, right? Because that was my first guess as to your problem. Go over to your FPR and with the FP gauge hooked up, kink the vac line to it and see what it does. If it skyrockets its functioning correctly, if it hardly moves or doesnt move at all thats your problem.

You should have around 45ish hooked up, at idle. Your pump or sending unit could be the problem too, of course. Check/replace filter and strainer as well. Also make sure your tank is as clean as possible, inside and out. You dont want a rusty, dirty tank because that stuff gets sucked thru the fuel delivery system and into the engine!

 

So your immediate problem is why the pressure is dropping?
when you loose pressure , have you clamped the return line to see if pressure comes back and holds?
If it does reg is not holding pressure;
if it doesn't then the pump is not performing as it should ( assuming you have the pump jumpered to run fulltime )

Not your problem but boiling fuel is in the engine bay ; in the fuel lines etc ; not in the tank

Wrong
He has it right ; 45psi with no vac
39psi with vac ( @ idle )

 

Problem solved ( I think). The car got to where it would die everytime I rode it within 15 minutes. I cut the trap door (I know) and took out the new delphi pumped and noticed the little rubber stopper thing on the bottom of it was pulled back into the pump slightly and was loose. I changed the sending unit with a spectre and another delphi pump and I've rode it for 2 days without problem. I put around 3 hours on it the first day basically in a row and today I rode it for around a hour and a half and it was about 85 degrees today. Unless something is burning the pumps up its fixed. Only time will tell. Thanks. And I've got a new AFPR for it, I'm waiting to run across a aftermarket intake before I take it apart.