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BEST in tank fuel pump and sender for GM TBI on cj7 jeep!

BEST in tank fuel pump and sender for GM TBI on cj7 jeep!

76cj7chick

Old Time Jeeper
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Location
WA
Vehicle(s)
1976 CJ7 Jeep with a engine/tranny/wiring harness out of a 1988 s10 blazer 4.3l v6 with th700r4 automatic tranny and a cj7 Dana 300 transfer case with Novak adapter.
Complete wiring harness from the s10 blazer. Painted with HOT PINK Pearl paint with standard sized metallic halographic pink flakes. Painted by me -a newb. New rear, front and side three wire LED lights, New parts, new custom dash-by me And a lot of guidance from fellow jeepers and lots of prayers etc.... :p
Howdy all!


I've upgraded my carb to a GM TBI system... And would prefer the in tank pump assembly...

I've heard Novak makes one... But am kindof strapped for cash... I am willing to pay up to $140 ish for the assembly or convert my current fuel sending unit to a fuel pump assembly?

Although I have a 76 CJ7 ---I installed a plastic 78-86 CJ7 jeep tank from MTS 15gal part # 0051...

Would it be easy and wise to convert my current sending unit to an electric fuel pump assembly? If yes, anyone have pictures of this process? :rolleyes: ---I'm thinking of using a fuel pump rated for 12-15psi, like E3902... But not certain if it will work properly as I don't have a bracket to hold it in place...
Just concerned about wiring... Do I need to drill a hole in the top or can I connect the pump power to the sender connector... Then there is the ground wire for the pump..

IF ANYONE HAS BEEN SUCCESSFUL IN THIS MOD PLEAAAAAAAAASE UPLOAD PICS AND INSTRUCTIONS!:drool:

OR

Get the Sender unit from Novak and install a lower psi fuel pump in it?


OR

Some people say that the sender for a yj 2.5l tank will work in CJ7 ... BUT I contacted MTS and they said that their YJSU-1P unit measures 9.5" long and top plate is the standard 3.5"
My CJ7 fuel tank has a 2" opening/hole...

PLEASE HELP! NEED TO DRIVE MY HEEP!!!! :notworthy::notworthy::notworthy:
 
Re: BEST in tank fuel pump and sender for GM TBI on CJ7 jeep?

Nobody?!?!!?:confused:

Guess I have to go with an in-line pump.. :rolleyes:
I want to mount it on the driverside of the frame... Anyone have experience with this that would like to share with me on how and where they put the pump?

(I originally had the pump and filter on the passenger side ALL the way on the tranny skid plate.. Problem with that was SOOOOO far from the tank...

Hope to hear from someone who has experience with this Fuel injection mod. :o
 
I have no experience with your upgrade but I know when installing a electric fuel pump you want it as close to the tank as possable and low enough that the gas as a siphon to the pump so all it has to do is push it to ths engine. So I would think on the frame rail just in front of the tank would be best. I hope this helps some.
 
I have an inline pump with the Howell tbi kit and it has worked pretty good for the last ten years or so, it even passes the Ca. smog check. The pump is mounted on the passenger side frame rail next to the Transfer Case . I was recommended to use the Airtex E8094 pump and I keep the pump supplied with the tbi kit in the Jeeps toolbox. I like to run 9-10 psi for fuel pressure. I would think it could be risky going off camber with just a few gallons in the tank, so I try to keep it as full as possible.
 
I missed this post earlier...

I just put an in tank pump but for a tuned port, just different pump.
I used a Bosch pump...you could just get one for a chevy pickup with a tbi engine.
The pickup in your sending unit is 5/16" same size as output on pump. Cut the tube so your pump will be just off bottom of tank... 1/16"-1/8". Use the good fuel injection clams to hold the pump on... It won't go anywhere.

I then ran the wires out the 1/4 return line fitting and sealed with a fuel resistant silicone... Jb weld would work also.

I just fired it up yesterday... Works like a champ. Pump was $64 screen about $6 through rock auto. Oem quality. :chug:

4A0DF856-4BE3-4D12-A953-5C7F78F025C0.webp
 
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I have no experience with your upgrade but I know when installing a electric fuel pump you want it as close to the tank as possable and low enough that the gas as a siphon to the pump so all it has to do is push it to ths engine. So I would think on the frame rail just in front of the tank would be best. I hope this helps some.


Hi Mtnwhlr! Thanks for your comment. ;)
 
I missed this post earlier...

I just put an in tank pump but for a tuned port, just different pump.
I used a Bosch pump...you could just get one for a chevy pickup with a tbi engine.
The pickup in your sending unit is 5/16" same size as output on pump. Cut the tube so your pump will be just off bottom of tank... 1/16"-1/8". Use the good fuel injection clams to hold the pump on... It won't go anywhere.

I then ran the wires out the 1/4 return line fitting and sealed with a fuel resistant silicone... Jb weld would work also.

I just fired it up yesterday... Works like a champ. Pump was $64 screen about $6 through rock auto. Oem quality. :chug:

4A0DF856-4BE3-4D12-A953-5C7F78F025C0.webp



YES! That is what I wanted to hear! :chug:
However, I've already started to install on the frame... If I can't get it to stay cool (since it will be near the hot exhaust) I will definitely pm you! :notworthy:
 
YES! If I can't get it to stay cool (since it will be near the hot exhaust) I will definitely pm you! :notworthy:
All you would need to do is mount a heat shield between them.
 
Did this to my 76 back in 2006:

Jeep pickup/sender, Walbro 255 LPH pump, and parts from a Mustang:

MustangPump.webp

FuelPump004.webp

FuelPump005.webp

Needed to extend the float which necessitated making the sender/pickup so that it could be taken apart:

FuelPump006.webp

FuelPump008.webp

FuelPumpInTank002.webp

FuelSystemPlumbing004.webp

The pump worked fine, but I have since decided to install an inline pump, as the intank would be a real PITA to replace along the side of the trail. A number of people are using the Airtex E2000 or E8228 pump without problems. I'm looking to run the Walbro GSL392 pump.
 
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Here's a pic from another forum showing a good place to mount the inline pump:

FuelPumpInstall_zpsd417f296.webp

I'm going to put my Walbro GSL392 in the same location, however I will be using -6AN fittings and I already have a good filter mounted:

EngineInFrame007.webp
 
Those are some pretty impressive in tank pump setups. I gotta ask this though, a properly set up pump should not have to be replaced at all, so I think there is a problem somewhere. I notice that Hack seems to place the filter on the outlet side of the pump leaving it vulnerable to damage from contaminents in the fuel tank. Also for those guys running electric fuel pumps, just how are they working for you? In my opinion, a tbi pump does not have to be one of those high pressure jobs that use a lot of amps and send most of the fuel back thru the return line anyway. For the in line pumps there seems to be two different ways to install them, one being close to the tank allowing the pump to suck up the fuel then push it out, or installing it midway at a low point and allowing it to siphon from the tank to the pump.
 
I gotta ask this though, a properly set up pump should not have to be replaced at all, so I think there is a problem somewhere.
You've never had an intank fuel pump die on you. In 2009 my 2002 Chevy Blazer was 140 miles from home when the fuel pump died. The pump in my son's 2002 Chevy C10 pickup died a couple blocks from his house on his way to work. Both vehicles needed to be towed. The dealership bill on my Blazer was darn near $1000 to get it replaced. The Delphi OEM pump unit was $480 of that bill (same part at NAPA was under $300). Luckily I had a service contract on my Blazer that covered all but $50. My son's didn't have a service contract, so his was totally out of pocket. However his bill was a bit lower having taken it to an independent garage and his tank was easier to remove.

Dropping a gas tank, in the middle of nowhere, is not my idea of a fun time. Just pulling the fill and vent hoses are a real PITA. Then you've got to remove the other hoses and wiring. Somewhere in the process you are also removing the skid plate and lowering the tank. If the tank is anywhere near full, you better have some cans around, or some buddies with partially empty tanks to siphon your gas into. Whereas, crawling under the CJ, removing a couple of easily accessible fittings and fasteners, putting in a replacement pump (tool box item) and driving out, seems a much more attractive idea.

I notice that Hack seems to place the filter on the outlet side of the pump leaving it vulnerable to damage from contaminents in the fuel tank.
The intank setup I first Hack Fab'd had a Walbro 'sock' filter installed on the inlet side of the pump. Note the bottom of the pump in the pic.

FuelPump006.webp

This is the norm for OEM intank pumps, where the idea is to protect the pump. If you look back at the picture of the stock Mustang pump you should also see the 'sock' attached to the bottom of the pump. Most of the people I know running inline pumps either have a 'sock' filter on the end of the pickup tube or a filter just prior to the pump inlet.

The pressure side inline filter is a smaller (in microns) element that is designed to protect the injectors. This is also the norm on all OEM EFI vehicles from what I've seen. I know I get constantly bugged by the guys at the oil change place to get it replaced when I have the Blazer serviced.

Also for those guys running electric fuel pumps, just how are they working for you?
Mine worked great. My experience is they work great, until they stop working. Then it's not so great.

In my opinion, a tbi pump does not have to be one of those high pressure jobs that use a lot of amps and send most of the fuel back thru the return line anyway.
EFI systems require a certain amount of pressure to operate. TBI and MPI have different needs. My MPI Ford EFI runs on 40psi (39.15 psi to be exact). Flow rate is also an important consideration. Having more than you need is not necessarily a bad thing. However having less than you need is most always a bad thing.

Here's a good article from Ford Racing in reference to selecting MPI EFI components:
http://www.fordracingparts.com/download/tipsPDF/ProperlySelectingEFIComp.pdf

For the in line pumps there seems to be two different ways to install them, one being close to the tank allowing the pump to suck up the fuel then push it out, or installing it midway at a low point and allowing it to siphon from the tank to the pump.
Depends on where and how the fuel is being picked up and if the pump is capable of either a large or small degree of self priming.

Most of the people I know that are running the Airtex E2000 or the E8228, have them mounted reasonable close to the fuel tank.

A side note on the E2000 pump, it was OEM on a number of Ford EFI applications, and is readily available at most auto parts stores.
 
Thanks for getting back with me on that Hack, I wasn't sure of the type of fi unit that you had. As I recall only Ford tried an inline/exterior fuel once then quit using it. Actually I did have an in tank pump die on me once but it was covered by warranty, I have also swapped electric pumps on my CJ on a busy freeway but the problem was a bad icm. I have now setup my pump as close as I can for a quick change operation. I am quite surprised to see you getting 40 psi on an inline pump and having it work well. Your previous experiences with in tank pumps do sound quite expensive also. It is nice to hear from a fellow Jeeper having success with an inline pump, if I have any issues, I will move the pump closer to the fuel tank. Running with my current system I was able to get my fuel tank down to 3 gals with no issues. I hope this provides some useful info for the op.
 
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... Actually I did have an in tank pump die on me once but it was covered by warranty, I have also swapped electric pumps on my CJ on a busy freeway but the problem was a bad icm. I have now setup my pump as close as I can for a quick change operation.
Mechanical things die. Electrical things die. Electro-mechanical things have twice the likelihood of dying, IMHO. For the homegamer, install those things where they can be readily replaced.

I am quite surprised to see you getting 40 psi on an inline pump and having it work well.
I haven't done the conversion yet, but I know at least three guys with similar or higher hp engines that are running inline pumps with zero issues. If you read through the Ford article, you will see that being able to get 39.15 psi to and across the injectors is paramount to obtain best performance.

Thanks for getting back with me on that Hack, I wasn't sure of the type of fi unit that you had. As I recall only Ford tried an inline/exterior fuel once then quit using it.

My CJ5 project has one of these:

Picture012.webp

Ford Racing 5.0L, Ford 'B' cam, Aluminum GT40 heads, GT40 tubular manifold, 65mm TB, 65mm MAF, 24# injectors, Ford Racing F-AMC 150 headers, 2.5" to 3" single exhaust, MSD distributor/coil/wires, 3G 160amp alternator, custom serpentine belt setup. EFI runs off a A9L computer (factory Mustang 5.0L manual Transmission ), with a custom harness from RJM. Ford Racing claims 345 horses from this setup, but it has not been dyno'd, as the vehicle is torn down for paint. Hopefully later this summer I'll be able to get it 'tuned'.

I've heard Ford used the E2000 pump along the frame rail in their Econoline Vans, in conjunction with a low pressure/high volume intank pump. Never investigated this, so it's pure speculation.
 
Holley Blue or Red label. Best for your money and you can't take enough fuel from em.
 
Thanks everyone for your responses and lots of good pictures too!
I've since modified a oem CJ7 fuel sending unit with a gm 12-15 psi electric fuel pump... Let me know what you think! Also, Can anyone verify what the OHMS are supposed to be between the ELECTRIC FUEL PUMP POWER WIRE AND GROUND?!?! (Just wondering since I modified a "special" hole for the power wire to feed through and put some nylon flat washers in-between the hole along with a rubber gasket-from the previous fuel sender unit...) DON'T need the Fuel tank To EXPLODE on me...:eek:


THANKS AGAIN FOR YOUR HELP!!! :chug:

Again, if you know what the ohm reading is supposed to be in regards to the ELECTRIC FUEL PUMP POWER WIRE to the sending unit.. I would really appreciate your help...
 
I am not really sure of what you are talking about, as there should not be any conductivity from the fuel pump power wire to the sending unit as they are entirely two different circuts. Hopefully your connections are secure and well insulated at the pump, as there is probably some conductivity in gasoline which would create a minor short from that power line to a ground. I would think you have done lots of research from other postings of people who have created these units.
 
I am not really sure of what you are talking about, as there should not be any conductivity from the fuel pump power wire to the sending unit as they are entirely two different circuts. Hopefully your connections are secure and well insulated at the pump, as there is probably some conductivity in gasoline which would create a minor short from that power line to a ground. I would think you have done lots of research from other postings of people who have created these units.


hi torxhead!

thanks for your response... urr... to respond to your question.
to clarify: i don't have the sending unit wire connected to the electric fuel pump power wire.
i drilled a separate hole in the top of the sending unit and installed a a small bolt, the electric power wire, then a nylon washer, then a rubber shoulder grommet... and then another rubber seal and nylon washer, nut then the connector for the electric power feed. (i didn't touch the sending unit wire or connector. it is still on the stock feed.)

so my concern/question is this:
if i use a ohm meter to measure the resistance or ohms to the electric fuel pump and ground --what should i get?
i know that the electric power wire isn't supposed to touch the metal fuel sending unit plate, but how many grommets/shoulder washers/nylon washers would be good to keep it from grounding out?

me scared.... :o
 
I missed this post earlier...

I just put an in tank pump but for a tuned port, just different pump.
I used a Bosch pump...you could just get one for a chevy pickup with a tbi engine.
The pickup in your sending unit is 5/16" same size as output on pump. Cut the tube so your pump will be just off bottom of tank... 1/16"-1/8". Use the good fuel injection clams to hold the pump on... It won't go anywhere.

I then ran the wires out the 1/4 return line fitting and sealed with a fuel resistant silicone... Jb weld would work also.

I just fired it up yesterday... Works like a champ. Pump was $64 screen about $6 through rock auto. Oem quality. :chug:

4A0DF856-4BE3-4D12-A953-5C7F78F025C0.webp


hi there~
thanks for your response... i have a concern about the electric fuel pump power wire grounding out to the metal fuel pump plate... did you use any special shoulder washers or nylon washers to keep the "hot" wire from jumping to the ground wire?
i used a small bolt, then power wire, then nylon washer, on the bottom side, then put a shoulder rubber grommet through the hole, another nylon washer and finally the nut... after that, i installed the connector for the power wire feed...
wondering if there is a better way to "insulate" the power wire so that it won't ground out, causing a short or explosion???:o
by the way, i didn't touch the stock fuel sending unit power connector on the fuel sender... instead, i drilled a separate hole in the unit and connected the power wire to the bottom of the screw with some nylon washers and a through shoulder rubber grommet...

i would love to hear from you! especially if you have pictures of how you assembled the separate electric fuel pump wires through the sending unit.... i really want to try starting the heep asap.... :driving:
 

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