Bad fuel pressure regulator? need advice for problem
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Joined: Nov 2008
Posts: 311
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From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Bad fuel pressure regulator? need advice for problem
I have a Spectre fuel pressure regulator 2517 and I'm having troubles with the engine staying running. I am having trouble getting fuel to continue getting to the carb. I can get the pumps to fill the carb before I start the motor, but as soon as I start the motor and rev it up a few tims it drains the bowls and the engine dies. I took it off the carb with the pumps still running and the fuel wasn't getting past the fuel pressure regulator at all. I double checked it and with the pump off and the regulator off the carb, turning the pump on starts putting fuel out the regulator. The one that I have only goes up to 5.5 psi though, is that going to make a difference? I'm sure that I probably need to get a different regulator but I'm not sure which one works the best.
Thanks
Thanks
Joined: Dec 2007
Posts: 1,924
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From: Minnesota
Car: 84 camaro, 88 trans am, 98 camaro
Engine: Modded , stock, LSX modded
Transmission: 700r4, 700r4, t-56
Axle/Gears: 327, 308, 373
Re: Bad fuel pressure regulator? need advice for problem
what carb do you have?
Thread Starter
Senior Member
Joined: Nov 2008
Posts: 311
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From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Re: Bad fuel pressure regulator? need advice for problem
Got the Edelbrock 1406 and both stock fuel pump and an electric carb pump, both deliver fuel fine through the regulator until it biulds pressure at the carb then that regulator locks up I guess.
Thread Starter
Senior Member
Joined: Nov 2008
Posts: 311
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From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Re: Bad fuel pressure regulator? need advice for problem
Bought another regulator and also got a guage to use so I don't have to pull it apart to see if it's getting fuel. Since I have both pumps running I'll probably disconnect the in tank one to see if that's going to make a difference. I will also put the guage before and after the electric carb pump that I installed to compare the fuel pressure from both pumps. At 12-15 psi I very seriously doubt that we will need a return style, but I'll check to see what the difference in pressure is. If I have to I'll pull the in tank one sometime and make it a carb pick up instead.
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Thread Starter
Senior Member
Joined: Nov 2008
Posts: 311
Likes: 0
From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Re: Bad fuel pressure regulator? need advice for problem
Well I'm going to go check the PSI from the carb fuel pump and see if it's under 10PSI, if it is I'll use the carb pump until I get money for the bypass type to use with the stock pump. I finally found instructions for the regulator that I have and it says not to install on systems greater than 10PSI. It also says that the internal valve of the fuel regulator closes when the outlet pressure reaches the pressure set on the adjustable dial. It may be possible that greater then 10PSI keeps the vavle in the regulator from opening back up.
Thread Starter
Senior Member
Joined: Nov 2008
Posts: 311
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From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Re: Bad fuel pressure regulator? need advice for problem
I can say this for a fact since I just tested it...12-15 PSI is not a problem for this pressure regulator even though it says a max of 10. HOWEVER... 20+ IS a problem and it won't work.
I just got done with the car and I can get it to work with just the carb pump running. The time that I had tested it before I had forgotten to unplug the oil pressure sensor/switch so the stock pump was turning on with the engine. I saw that pressure so I thought that maybe the carb pump had too high of pressure until I remembered to unplug the OPS. After I pulled that plug the fuel pressure was about 12-15 with the carb floats closed and about 9 PSI when they opened.
Remember that these PSI numbers that I'm citing are BEFORE the pressure regulator, NOT after. I have the pressure regulator before the carb and after the pressure guage.
I did check the setup with the engine running and the engine finally stays running!!! Hopefully I don't screw anything else up now, lol.
I just got done with the car and I can get it to work with just the carb pump running. The time that I had tested it before I had forgotten to unplug the oil pressure sensor/switch so the stock pump was turning on with the engine. I saw that pressure so I thought that maybe the carb pump had too high of pressure until I remembered to unplug the OPS. After I pulled that plug the fuel pressure was about 12-15 with the carb floats closed and about 9 PSI when they opened.
Remember that these PSI numbers that I'm citing are BEFORE the pressure regulator, NOT after. I have the pressure regulator before the carb and after the pressure guage.
I did check the setup with the engine running and the engine finally stays running!!! Hopefully I don't screw anything else up now, lol.
Last edited by mos68x; Sep 22, 2009 at 09:36 PM.
Joined: Mar 2000
Posts: 43,187
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
12-15 psi is a problem for the pump because of the reg you're using. A dead-head reg will kill even the low pressure in-tank electric pumps.
Don't run your in-tank pump with that dead-head regulator. Period.
Don't run your in-tank pump with that dead-head regulator. Period.
Thread Starter
Senior Member
Joined: Nov 2008
Posts: 311
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From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Re: Bad fuel pressure regulator? need advice for problem
Apparently you didn't read my post, I'm NOT using my in-tank pump. I'm using a CARB pump that I bought a while ago for a different project. I even unplugged the OPSU to keep the in-tank one from turning with the oil pressure switch.
Re: Bad fuel pressure regulator? need advice for problem
Joined: Mar 2000
Posts: 43,187
Likes: 43
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Yes, I read your post. You didn't acknowledge that running a dead head reg with a low pressure in-tank electric was not the right thing to do. Merely saying you disconnected it (which sounded like a diagnostic action) doesn't get there.
Now, as MR NICE pointed out, you have another problem, that being trying to suck gas through a non-operating in-tank electric. You might get by with it for a little while, but it will lead to other problems.
Now, as MR NICE pointed out, you have another problem, that being trying to suck gas through a non-operating in-tank electric. You might get by with it for a little while, but it will lead to other problems.
Thread Starter
Senior Member
Joined: Nov 2008
Posts: 311
Likes: 0
From: Ft Campbell, KY
Car: 1991 Camaro RS/Z28
Engine: 357 Edelbrock Intake & Holley Carb
Transmission: WC T-5
Axle/Gears: whatever stock is
Re: Bad fuel pressure regulator? need advice for problem
This 'bypass' of the stock in-tank pump is not permanent, just a temporary fix until I have more funds...which will hopefully be midmonth Oct. I will probably order the Mallory 4309 regulator since this is the only one that I have heard anyone actually mention by part number. Almost all of the ones that I saw that were bypass type were meant for FI type pressures. This Mallory one should do just fine I think, unless anyone else has a better alternative.
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Joined: Aug 2009
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From: AZ
Car: 1978 Chevrolet impala
Engine: 350ci 300hp/356tq pace crate
Transmission: 700r4
Axle/Gears: 3.42 Yukon posi
Re: Bad fuel pressure regulator? need advice for problem
The Procomp regulator you are talking about is not a diaphragm style regulator and will not work for a stock fuel pump/return line application.
Check out holley 12-803BP. Same thing as the mallory, save you 20 bucks.
Check out holley 12-803BP. Same thing as the mallory, save you 20 bucks.
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