fuel injection

[eyehunter78]

We have a 1989 Camaro with 305 tpi. When we turn the key and the fuel pump kicks in the fuel pressure is at 42psi. When you turn key off it drops to 0 in a couple seconds. Should this stay at 42psi or drop to 0? Could this be a fuel pump, fuel regulator problem, or injector ??

[Jeremy airjer W]

If it was the injector you would see it dripping into the throttle body.

That leaves us with the regulator or the fuel pump.

There should be a pressure line and a return line going to the throttle body. the metal lines should convert to rubber lines at some point. ***make sure these are rubber lines and not hard plastic or braided lines, you will ruin them in the next step if they are not rubber****. Turn the key on and wait for the pump to stop running. Carefully pinch off the rubber high pressure line. If fuel pressure holds the pump is bad. If fuel pressure continues to drop the regulator is bad. The fuel pressure gauge should be upstream (engine side) of where you decide to pinch.

[98prosport]

did the post say "TPI" or "TBI"? TPI is multi port and yes it could be an injector or regulator or pump.

[Whoaru99]

What is the symptom driving you to check the fuel pressure?