very low fuel pressure

i have a 96 z28 5.7 lt1, when i go to start car i have to wait, like the fuel has to get there. then it starts and runs great. will this be the fuel pressure regulator or fuel pump? i can tell you I dont have pressure when i release pressure valve.

If you are sure there is no pressure - a pressure gauge would tell you more than simply pressing the valve core - then is could be a dead fuel pump, or a failed fuel pressure regulator. But since it eventually starts, and "runs great", it may not be either.

Why not put a fuel pressure gauge on it and find out exactly what is happening? It could be a faulty check valve in the fuel pump allowing rail pressure to drop to "0" on shutdown, leaking injectors, etc.

How about a plugged up fuel filter??

If the fuel filter was plugged to the extent it prevented any pressure at startup, and extended the startup period, its sort of hard to understand how it would provide adequate fuel once the engine started, allowing it to "run great". But never hurts to check it.

If the fuel filter was plugged to the extent it prevented any pressure at startup, and extended the startup period, its sort of hard to understand how it would provide adequate fuel once the engine started, allowing it to "run great". But never hurts to check it.

I understand that but I always start at the simplest part of a system first especially when it's an often over looked maintainence item.

ok so i thought it will be a good idea to cheange filter since it looked to be original.. so that was not the problem... i have to get a fuel pressure gauge.. i can tell that the starting is starting to take a little more time.

Verify a drop in fuel pressure via a gauge. If it is dropping, swap the pump out. Should be fairly cheap and easy.

Check pump rely , does it happen when cold or sitting for long time

if so you have to wait untill oil pressur swich turns on the pump,

one way to check is to turn ignition on (don't crank) and hear if fuel

pump primes.

it does it when i let it sit long.. or over night.

it does it when i let it sit long.. or over night.


Did you check if the pump pimes ( if it turn on for a few second and turn

off) When ignition on and engine not running.

sound like it is priming.. i just have to get a pressure gauge

sound like it is priming.. i just have to get a pressure gauge

So either the hose inside the tank has got a tiny hole or you pump

need to be changed.