Ok,

After first starting to explore this option roughly a year ago, I've now ordered every part of my fuel injection conversion EXCEPT FOR the fuel system.


Chris Meyer @ EFISystemPro.com helped me with putting together my Holley HP components and how he's helping me make sure I don't forget anything that I need for the fuel system, but I need to answer a few pointed questions about the 1982 fuel senders that I just can't seem to find.


Eckler's has some great photos of the sending unit here: https://www.ecklerscorvette.com/corv...unit-1982.html

I'm not looking to buy a sending unit with a fuel pump as I'll need a modern high pressure pump so I'm looking at buying the sending unit from here: https://www.1aauto.com/1982-chevy-co...=194224&y=1982


The information that I'm looking for is the diameter and length of the feed and return line for the 1982 sending unit. (How close the feed and return lines come to the bottom of the tank?)


I'm going to use a Walbro 255 l/h in tank pump but it needs to mount to the feed line with a small section of submersible EFI tubing- to get the Holley fuel mat properly on the bottom of the tank, I need these dimensions and I can't find them to save my life.



My fuel system will comprise of:
Walbro in tank EFI pump
1982 sending unit
large Holley fuel mat (to help avoid fuel starvation as there's no EFI fuel tanks for late C3s)
Earls Vapor Guard tubing- feed & return
Unknown Adjustable Fuel Pressure Regulator (Aeromotive model #'s confuse me)
(Yes, this is pretty much exactly what I proposed a year ago before I got distracted by everything else that was wrong with my car once it got out to me.)

Adam

 

I think you will have to get all your parts together then measure what you have .its going to be a custom fit .take pics and show what you came up with.

 

I have a new 82 tank and pump/sender that I haven't hooked up yet.
I'll dig it out tomorrow, measure the sender and take some pics.
I think that Holley fuel mat, if it work like it's supposed to is a really good idea. Good luck with your new system.

(really) OLDGUY

 

Some good ideas here, following along because this is the winter project for the 69. T

 

Got some pics. Don't know if they help much. The fuel pipe is 3/8 and return is 5/16 Be aware that the return line is also the pump mount
and terminates at the bottom next to the bottom of the pump. Could cause a problem with Holley mat. Maybe a diffuser of some sort to spread out the flow? Also, the whole thing angles into the tank so the pick-up is forward of the mounting hole. The end of the pump (I'm using a Walbro GCA758-2) hooks right to the filter sock so there is not a lot of room between pump and tank. Looks like 16-111 has the right connector for the pump.(758) Don't know about any other pump.
Hope this helps a little. When you get it figured out then you can help me.

 

I would need justification on this; Holley sock is $144 at jegs
sender from Ecklers is $114
and Summit wants $110 for Walbro pump
totaling $368
A Tanks Inc complete unit is $226 from Summit
They in the end both do the same thing but with a $142 difference, I'm trying to do the conversion for around $1500 with the Sniper and my wish list at Summit is around $1450 right now and with the misc parts I forgot to put on my list going with the Walbro set-up I'd be approx. $150 over. T

 

It looks to me, you forgot to add the Holley mat to the Tanks pump set-up, ,for your priceing, don't skimp just for a few hundred bucks,,, i used Holley mat, and love it, look for my post and pics on the build,, very much like yours, only with a 1975 tank and sending unit conversion, ,,,,, your on the right track, just don't cheep out , , do what your comfortable with, if it costs more, take your time and save up more for the project, you only want to do it one time, and have confidence in your build,,as for the dimensions for your sending unit and mat pickup depth, you will have to do an actual measurement to get it correct, just keep the mat touching the bottom of the tank somewhere, and it will work fine.,,, your doing a great job,,

 

The 'Tanks Inc' PA series of in tank fuel pumps have a tray or baffle around the fuel pick up. They claim this is all that's needed. I would think twice about that if it was a race situating with long sweeping corners, but street driving it should be okay. That is why I picked the 'Tanks Inc'. The Holley mat sure looks like a fine product and I just might have to figure out how to put one in the 6t8. Thanks T

 

Ok, here's the detailed parts list and prices I ended up with; if you guys can give it a quick once over and make sure I didn't forget anything:

Partsmaster 10-micron 73482 Filter, $12.18
Walbro / TI Automotive GSS342 Fuel Pump, $76.50 (255 l/hr)
Walbro 94-615 GSS Fuel Pump Pigtail, $6.23
Holley 16-111 15x3 HydraMat for Walbro pump, $159.95 This is optional; you can use the sock that comes with the fuel pump and save $160 if you desire, but I wanted it.
Earl's Vapor Guard EFI Hose, 3/8-Inch x 20 feet 752066ERL, $92.60 If you're going to use your original steel line as a return you only need 10 feet; I'm using new EFI hose for the pressure and the return as my steel line had 2 sections of rubber tubing and I'd just rather start with all new for $50 more.
Holley EFI/Carb Fuel Pressure Regulator, 12-879, $128.95 I'm actually shocked at the price of this thing- vacuum/boost port, return capable, and a pressure gauge port- I'm using a digital pressure fuel sensor here
Earl's 3/8 Inch MNPT to 3/8 Inch Hose Barb Fitting, 781666ERL, $6.13 x4
Vibrant 3/8-inch EFI Hose Clamps, 12237 $5.93 for 12

Total $506.86. ($346.91 without the Holley Hydramat)


Then another $86 for the 82 fuel sending unit: https://www.1aauto.com/1982-chevy-co...=194224&y=1982

My Holley HP EFI harness has a built-in relay with 14 gauge wire which will support the 10 amps that my fuel pump will run @ 5 bar (I plan to run it at 3 bar unless it responds well to running more pressure.); so no need for any additional relay or wiring there.




Adam

 

You will need the Hydramat if your tank does not have a sump for EFI.
The regular sock is just a filter.

I avoided the whole return line from the engine routine by using the C5 LS fuel filter/regulator.
58 PSI and only 1 line to the front of the car.
I also opted to use OEM style nylon EFI tubing and steel fuel line vs rubber hose-
I get nervous running huge lengths of rubber fuel line the entire length of the car. Just seems like an accident waiting to happen. I also hate running more fuel lines than I need to. lol

Looks like you've pretty much got everything covered for what you are trying to accomplish. You'll also need various clamps etc to hold the fuel lines in place and wire for the pump itself but otherwise, your list looks complete.

I wish I would have known about using the 82' sender- I didn't think it would fit my 69' tank.
Live and learn.

 

List looks good, , , , don't forget the short fuel line from your in tank pump to your bulkhead fitting in the sending unit,, remember you CAN NOT use regular fuel line for this ,it MUST BE submersible fuel line, or you WILL have issues, , ( you will think the pump is going bad,, but in less than a year, regular line will degrade and restrict fuel flow, and then pump will fail,)
. This is what I used, not cheep, {aprox, $25.00 a foot}
. Also, I used 12ga wire from relay to fuel pump, and also pump ground wire,,, you don't want any voltage drop going to the pump, or it will shorten the pump life drastically, , Hope this helps,,,teddy

 

oldguy
Did you end up using the Walbro GCA758-2? I gather that the pump outlet and the sender are both 3/8"? Did it all come together well? I'm considering going to an 82 sending unit so I am also looking for pump ideas.

thanks
jcj

 

Might as well jump in on this now that you brought this back from the dead....

Some miss information in this thread.

- The holley hydramat is technically a poor choice for an in tank pump unless its designed for a higher Micron rating (lower number) which causes the pump to work ALOT harder to suck fuel in which is how you burn out pumps.
- Holley hydramat is a 5 micron rating and a normal pre pump sock/filter should be no less than 100 micron, this is why people burn out fuel pumps way before they should be dying... you basically suffocate the pump causing cavitation, loss of fuel pressure and flow and a early pump death.
- If you google and search you will find threads of this exact issue. I know people will say "well they sell them with the pumps and a lot of people use them" that's because when your pump burns out they get to to sell you another pump and will probably say the hydrat is a 1 time use so they get you for 2 things $$. Also just because people are using it doesn't mean they aren't wearing the pumps out faster.
- DO not use foam like Aeromotive yellow stuff they sell with the pump swap kits... that stuff falls apart and causes a mess.
- NEW style EFI pumps like walbro have the 100 micron pre filter and this is NOT JUST A FILTER... it has similar wicking capabilities as the hydramat and they don't charge almost $200 for it.
- Do not attach a baffle to the return line, it should be affixed to the tank otherwise the fuel sloshing around can fatigue the return line and break it off which now you have lost the support for the pump.

You have 4 options with these cars.

1. Swap the filler out for the 82 style and put on a walbro 255 with a normal walbro 100 micron sock and install. You could probably run the tank down to 1/4 of the way before really having any issues (unless you road race/autoX)
2. Swap the filler out for the 82 style and put a walbro with hydramat and hope you get a few years out of the pump.
3. Swap the filler out for the Holley drop in unit which is only like $350 but comes with sender, pump and hydramat, but be prepared to swap the pump out in a few years. Your stuck with LS 58psi fuel pressure I believe.
4. Get a new baffled tank with normal 100 micron sock (exactly how the OEMs do it).

Depends on your budget but I would do #1 as its the cheapest and will work for 90% of people or jump to #4. I dont see how the hydramat can be so expensive when they include it with the holley sender and 255 pump in their kits all for $350.