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73-87 Chevy _ GMC Trucks => Fuel Systems and Drivability => Topic started by: CTCash on February 01, 2021, 05:46:05 am
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I am installing an L92 into my 1987 V10. This fuel rail is the returnless style fuel rail. I am curious what is the best way to run the fuel system to keep my dual tanks.
Option 1: Place a Filter/Regulator between each Sending Unit to the Selector Switch. Then use a 3 port or 6 port with the 3 unused ports capped. Thus, purchasing 2 Filter/Regulators.
Option 2: Run the fuel lines as usual and place the Filter/Regular after the Selector Switch. Thus, purchasing 1 Filter/Regulator.
I am asking because I am not sure if it would be better to Regulate prior to reaching the Selector Switch. Thank you in advance!
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Check with the manufacturer of the pump and see what they recommend.
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Just use one filter regulator, no need to purchase two! BTW, this is what I did on my '91 with the 2004 LQ4.
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Just use one filter regulator, no need to purchase two! BTW, this is what I did on my '91 with the 2004 LQ4.
ehjorten , What type of fitting did you use for your selector valve to the fuel hose? I am just curious, as I will use the AN fittings but unsure as to what will work on the selector valve hard-line. It seems like the "hard-line tube fitting to AN Male adapter" would work. An AN dealer said to run a small rubber hose and connect an AN-to-hose barb fitting from it. If there is an alternative, I would like to try that. Any Suggestions? Thank you!
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I just used the fuel injection hose clamps. The ones like these: https://www.summitracing.com/parts/sum-390581?seid=srese1&gclid=Cj0KCQjw0caCBhCIARIsAGAfuMzZIZ2lmtZV1qmys-6LqEtcnBWLd1IjEBzxWk_C64jFBIbqHWKjuBwaAnf4EALw_wcB
I cut off the crimps for the old fuel hose to steel lines, replaced the 30 year old fuel hose with fuel injection rated hose, and used Oetiker clamps to re-secure it to the steel line: https://www.buyfittingsonline.com/stainless-steel-beverage-fittings-oetiker-stepless-ear-clamps/?gclid=Cj0KCQjw0caCBhCIARIsAGAfuMxR5wj9VrtHx7yVAkxrnnhgKzZ1_zcsL3PuFqPElr_laNkcLKFURYQaAl_8EALw_wcB
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ehjorten ok awesome. Thank you. Did you reconnect your lines up to the vapor canister? Wasn't sure whether I wanted to reinstall another one and run the lines, leave it without a hose, or run a short hose to a small filter close by.
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I have the vapor canister still in the truck and it is hooked up to the lines in the rails and hooked up to the vapor canister purge valve/solenoid on the intake manifold. The Vapor Canister Purge Valve is normally closed in Open Loop, but is Open in Closed Loop when the fuel trims are active.
The PCM does a diagnostic function test to look for a vapor leak (loose gas cap). In order for this to function, you need to have the Fuel Tank Pressure sensor and the Vent Valve that is attached to the stock LS Vapor Canister. This lets air back into the Vapor Canister (It closes for the Vapor Leak test). I believe you also need to wire in the fuel level sensor into the PCM. This functionality is NOT needed for the Vapor Canister Purge Valve to function. I have heard of a guy that retrofitted a 1997 Tahoe Vapor Canister under the hood to get the functionality to work, but it isn't necessary. All of this stuff is just for the Leak Test functionality.
You can tune out in the software, the Evap Vent, Fuel Tank Pressure Sensor, and Evap Leak Codes in the PCM.
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You can tune out in the software, the Evap Vent, Fuel Tank Pressure Sensor, and Evap Leak Codes in the PCM.
This is exactly what I did. Works great. I also used EFI clamps for my selector switch with -6 braided lines double clamping just for safety due to proximity to exhaust. Mounting the fuel filter/regulator in the OE location would be a great deal. If you plan on doing any real power additions, I recommend using an aftermarket return style regulator.
Any pics?
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What pics would you like?
You can tune out in the software, the Evap Vent, Fuel Tank Pressure Sensor, and Evap Leak Codes in the PCM.
This is exactly what I did. Works great. I also used EFI clamps for my selector switch with -6 braided lines double clamping just for safety due to proximity to exhaust. Mounting the fuel filter/regulator in the OE location would be a great deal. If you plan on doing any real power additions, I recommend using an aftermarket return style regulator.
Any pics?
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Just encouraging CTCash to put up some pics.