C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Installing my new Fuel Pump Sending Unit

Old 03-09-2019, 04:39 PM
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Default Installing my new Fuel Pump Sending Unit

Today I received my new Fuel Pump Sending unit from Corvette Mod. I decided to buy a entire new Unit verses
just changing out the Fuel Pump since it was the original one after 23 years in the car. My original one came out
very easy with no issues and fortunately all three fuel lines slid off fairly easily with some tugging.

Question #1: SOC/FILTRATION Position

What truly is the best position for the SOC at the end of the pump when reinstalling unit. After reading many threads
some suggestions are in the 9:00 o'clock position lined up with rear axle and many say front to back with longer
part of the SOC facing the rear bumper at 12:00 o'clock. When setting in the vehicle in that position - should it be placed in the
yellow tray with the fuel pump as well? Mine seem to be more at the 1;00 o'clock position - not sure if it was laying on
top of tray or in the tray . I am sure the most important issue is that the top of the sending unit lays flush on the gasket
and gas tank hole evenly as possible when reinstalling and try not to pinch the SOC. Any feedback and suggestions appreciated.

Question #2:

From what I have read in all the threads - the float assembly just needs to be carefully dropped back in the tank
when reinstalling the complete unit. Their is no collaboration needed and the gas gauge in the vehicle should
register the correct amount of fuel. I just want to make sure that is all that is needed. The ECM should kick
in when the key is turned on (wait for two second hmm - for sure). I have just under 1/4 tank of gas covering
the yellow tray. I may add another two gallons of fuel, once I hear the hmm sound, making sure the pump is fulling
submerged before I actually start the car. Fuel lines will be tighten up first with double clamps on intake fuel Etc.
like it was when dissembled unit.

Thank you for any feedback and overall a very easy procedure so far - want to make sure I set the unit back into
fuel tank correctly.

Thank you again

Last edited by vtech; 03-09-2019 at 06:01 PM. Reason: spelling
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Old 03-09-2019, 06:06 PM
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it's super easy. Don't over think it. You can only install the sending unit one way really so it'll work itself out.

turn the key to the accessory position, let it prime for a second and then you should fire up pretty quickly thereafter with minimal cranking. I've removed mine probably 15-20 times over the years and at this point can remove and reinstall in 10 minutes including tightening all the bolts
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Old 03-09-2019, 06:25 PM
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Just reassemble so it looks the way the OEM did when you removed it.

Did you purchase a new gasket for the ring?
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Old 03-09-2019, 06:50 PM
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Yes, the new sending unit came with a new Gasket which I will install. It looks like the new sending unit has
the SOC sitting at the 12:30 position. I may try to just drop it in the tank in that position. Curious - will the
SOC position - if incorrect - effect the performance of the vehicle in anyway? I agree to install the SOC the
way I removed the OEM unit. Just curious if the 9:00 O'clock position, inline with the rear axel, is better than
front and back 12:00 o'clock position of SOC. Lastly, does the SOC need to lay in the Yellow Tray like the pump.
It is very hard to see if that is happening as I lower the sending unit into the Tank.

Thanks again.
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Old 03-14-2019, 02:19 PM
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Default Follow up

SUCCESS!! I just wanted to thank all of you for your guidance and suggestions on installing my Fuel Pump Sending Unit.
Per your suggestion, I reinstalled the SOC, in the exact position it was set as the OEM unit I removed - 1:00 o'clock.
The new unit slid in like a Glove and seated perfectly on the Yellow Tray like designed. After torqueing down the 10mm
bolts per spec with new Gasket - seated very well on the top of tank - no leaks or vapor smells. Vehicle fired up and ECM
learned the new pump with no hesitations. Driving vehicle on DAY 3 and running like a Swiss Clock - firing up and honestly
seems to run much better than ever before.

Just FYI, I went with the Corvette Mod Stainless Steel Fuel Sending Unit suggested by many members including the SO CA
corvette mechanics I spoke too. I also purchased it with the Fuel Pump and components, that you need to assemble as they
ship unassembled to the sending unit. Very simple to assemble fuel pump on sending unit. WOW, very pleased with component
and the float sending registers and operates way better than my OEM seem to. It sends accurate fuel levels to the DIC Dash
now listing the accurate data with remaining miles before empty and MPG information. It seem to take about 30 minutes of driving
before all the DIC Data was registering.

At the end - I strongly suggest the Corvette Mod Fuel Sending Unit. You can buy it with or without fuel pump. If I have any troubles
with fuel pump - I will let you know. If I do I probably will add the AC/Delco Pump - but hopefully it will hold up. Regardless the
sending unit itself is awesome. I decided to go this route verses the DELPHI unit and glad I did.
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