No fuel pressure regulator?

[whitelightning603]

87 Silverado/2004 5.3/4L60E project. Runs great, however when starting have to turn key to run and wait for pump (new AC/Delco 58lbs in both tanks) to bring pressure up. With gauge connected pressure increases to app 55 then bleds down to 10. After starting, pressure is constant 55 lbs. Corvette filter/regulator between tank switch valve and fuel rail. I understand some years have a regulator on left fuel rail. This one had none. Does Corvette filter/regulator have check valve? Problem happens with either tank. No other posts mention this problem. Thanks in advance for your replies.

[79bonanza]

If it is a returnless system it will bleed off after you cycle the key. its part of a design of a returnless type fuel system. Im not positive but i think the corvette filter will have a check valve to bleed off pressure.

[Custom 68]

mine is the return style and yes after a while it will bleed down some but after 3 years it has never been a problem. It will build the pressure quickly.
Now it will stay at 50 or above for a couple hours if I remember correctly.

[BR3W CITY]

throw up a pic, I'm curios how the stock rail with no return looks on there...I'm used to what the truck return system looks like, and the car return less system, but havent' seen a return less truck.

[clinebarger]

The check valve is built into the pump or "pumps" in your case. The vette filter/regulator has a spring loaded diaphram built in to regulate the pressure to 58psi. The pump is capable of making 100psi. You have a leak. I would suspect the tank switching valve....They were never designed for high pressure & chould be leaking internally. My suburban can sit for a month & start right up

BR3W CITY here some returnless truck setups, flexfuel engines have metel fuel rails, others have plastic.

[whitelightning603]

Thanks for the replies. This is the tank selector valve that I replaced the original with. It will not switch tanks unless the ignition is off. Then when ignition is turned on, it will activate. Could the pumps be overpowering the selector valve and leaking pressure? Do I need to place an additional filter/regulator between the tank and tank selector valve? Or could it be a faulty tank selector valve?

Product Description: Pollak Motor-driven 6-port Electric Fuel Tank Selector Valve 42-300P JCW812705.

POLLAK MOTOR-DRIVEN 6-PORT ELECTRIC FUEL TANK SELECTOR VALVE For fuel-injected systems operating up to 65 psi. Designed to prevent returning fuel to incorrect tank. Weatherproof fiberglass-reinforced nylon valve body. Valve grounds to frame. Meets or exceeds DOT standards. Fits 3/8 I.D. fuel hose. Recommended fuse: 10 amps. Can be wired so original dash gauge indicates fuel level in either tank. Includes: switch, faceplate, wiring connector, instructions. Hoses not included-order separately. 6-port valve required on vehicles with 3 lines attached to fuel pump. For 12-volt systems.

[clinebarger]

Originally Posted by whitelightning603

Thanks for the replies. This is the tank selector valve that I replaced the original with. It will not switch tanks unless the ignition is off. Then when ignition is turned on, it will activate. Could the pumps be overpowering the selector valve and leaking pressure? Do I need to place an additional filter/regulator between the tank and tank selector valve? Or could it be a faulty tank selector valve?

Product Description: Pollak Motor-driven 6-port Electric Fuel Tank Selector Valve 42-300P JCW812705.

POLLAK MOTOR-DRIVEN 6-PORT ELECTRIC FUEL TANK SELECTOR VALVE For fuel-injected systems operating up to 65 psi. Designed to prevent returning fuel to incorrect tank. Weatherproof fiberglass-reinforced nylon valve body. Valve grounds to frame. Meets or exceeds DOT standards. Fits 3/8 I.D. fuel hose. Recommended fuse: 10 amps. Can be wired so original dash gauge indicates fuel level in either tank. Includes: switch, faceplate, wiring connector, instructions. Hoses not included-order separately. 6-port valve required on vehicles with 3 lines attached to fuel pump. For 12-volt systems.

Sounds good, I didnt know they made aftermarket high pressure selector valves.

The fact is.....Your fuel system has a external or internal leak causing you to lose prime.

Are you using "high pressure" fuel hose w/ clamps between the fuel pumps & senders?

[whitelightning603]

Sorry for the late reply, long hours at work lately. The tank selector valve that I replaced was identical to the new one, so I reused the existing fuel lines which consisted of factory hard lines crimped to rubber fuel line (single fuel injection clamps). Since they were difficult to take off and put on, I assumed they were OK. However now that you lead me in that direction, I believe I need to replace those. How else are we going to isolate the problem, right? Thanks for the encouragement. I'll keep you all posted.

[clinebarger]

Originally Posted by whitelightning603

Sorry for the late reply, long hours at work lately. The tank selector valve that I replaced was identical to the new one, so I reused the existing fuel lines which consisted of factory hard lines crimped to rubber fuel line (single fuel injection clamps). Since they were difficult to take off and put on, I assumed they were OK. However now that you lead me in that direction, I believe I need to replace those. How else are we going to isolate the problem, right? Thanks for the encouragement. I'll keep you all posted.

That would be a external leak, Im sure you would smell raw fuel?

The hoses Im talking about are in the tanks between the pumps & senders.

[whitelightning603]

I don't smell raw fuel. The hoses in the tank that connect the pump to the sender were replaced with the pump(s). I got another filter/regulator,just haven't time to change it. Don't you just hate it when your work interfears with your projects? Oh yea, that's how we afford our projects.

[whitelightning603]

Update on my fuel pressure problem. Mr. Clinebarger nailed it. I had a pinhole in the rubber fuel line between the pump and the sending unit......in both tanks. When I installed the pumps, I used the short hose that came with the pumps. I replaced the hoses and used fuel injection clamps. Now pressure holds and starts normally. Thanks for the encouragement.