I have a 1985 pontiac firebird 305 TPI, I have had a lose of fuel pressure and not quite sure why, please read fully and help me to determind what I did wrong. Keep in mind I have limited knowledge of the TPI system, Im just got my hands dirty from overhearing people talk about it.

Once I turn my key I hear the fuel pump turn on then stop, so I know the fuel relay and the fuel pump is working. However I have no pressure at the rails, nothing, dry as a bone when I push the tab down to see fuel pressure. Now, please correct me if Im wrong, but I figured I should expect fuel pressure at the rails before starting the car. I found that I am recieving fuel up to the fuel pressure regulator, so I removed the plentum and changed the regulator. Still, no pressure at the rails, car still doesn't start. I resieved word that the filters could be the problem, so I changed the inline filter under the car and not only changed the filter in the tank, but installed a 255LPH pump. Installation was clean, and I m getting strong fuel flow up the the fuel pressure regulator. Still, no fuel passed the regulator, car still doesn't start. Now, here's another area that I need you to correct me if Im wrong, I figured that if fuel is to pass the regulator, the pressure of the fuel needs to be strong enought to lift the little tab on the regulator up that is covering the inlet hole that allows fuel the travel through the rails. Either that or the vaccuum lifts the spring of the regulator up to allow the tab that is covering the inlet hole to uncover it. However, there's no vaccuum less the car is on right? Iam seeking serious help, please people, tell me, what did I do wrong!?

 

If you fuel pump is running...I'd check your regulator or at least pressure at the filter...not to be a wise *** but I had a GTA with a similar problem and I found out that the digital gauge was not working properly and I needed gas

 

if you are getting fuel to the regulator, then you have fuel in the fuel rail. the fuel pressure regulator relieves pressure to maintain it, not permits pressure. install a fuel pressure guage to make sure you have enough pressure(38-43psi). if not, problem is in the fuel delivery or the regulator is stuck open. if there is plenty of pressure, then you have a possible injector problem. you do not need vacuum to get fuel pressure at the rails.

 

Well the problem is to get the regulator to allow pressure through the rails, it's stuck closed, completely blocking fuel to the rails. I have 0 psi in the rails, no fuel at all. The sring that is pressing the regulator down is so trong it blocks the inlet whole in that little regulator assembly. You know what I mean?

 

the fuel has to pass through the rails to get to the regulator. the regulator relieves the pressure to control it.

 

ARE YOUR FUEL LINES ARE REVERSED ???
Fuel goes into the rails and out through the regulator.
If you have the supply from the pump going to the regulator, you will not get fuel.
Double check them.

 

i thought it was impossible to mix them up. i guess it might not be and would explain his problem.

 

They should be different sizes at the hard line connections. If he has any custom lines done there's a chance it could have happened.
The only thing that would explain exactly what he is describing.

 

Holy sh*t guys you're are all right, my lines are crossed! Im an insult to the automotive name. Guys thanks alot!

 

At least it was something simple to fix