Product Installs

Video: Installing a Summit Electric Fuel Pump in a ’79 Cherokee

Here is my 1979 Jeep Cherokee I call the Big Chief. I know, I know! It’s not a Chief, but it is a Cherokee despite the four doors, and it is big, so the name is stayin! It’s got an Eaton HO72 rear end from a ’69 Chevy with disc brake conversion, Dana 44 front from a ’77 Chevy K20, 4.56:1 gears, SOA front suspension with 3” K5 Blazer springs, 63” Chevy springs with custom shackle flip in the rear, AMC 360, TH400 transmission, and that hideous Borg Warner 1339 Quadra-Trac transfer case with a Mile Marker part-time kit. (Image/Josh Hahn)

A while back, I got my 1979 Jeep Cherokee back on the road after swapping in some full width ¾-ton axles, 63-inch Chevy leaf springs with a shackle flip in the rear, and a spring over the axle conversion in the front.

Needless to say, I was very excited to drive it, test it, wheel it, and do all the other fun things Jeep owners do.

Unfortunately, a meager five miles into its inaugural journey, the Holley red fuel pump burned out, leaving me stranded. Luckily, some fellow four-wheel-drive enthusiasts happened to drive by, hooked the Big Chief up to their big ol’ lifted Dodge, and towed me home. Long story short, I needed a fuel pump, so I got in contact with Summit Racing to try their version of the Holley Micro pump — the Summit Racing Universal Electric Fuel Pump (SUM-G3146).

There are a few things you need to keep in mind when selecting a fuel pump.

First, do you have fuel injection or carburetor?

Fuel injection requires a higher PSI, typically 40-60 PSI, in order to atomize the fuel flowing through the injectors. Subsequently, a carburetor requires a much lower PSI, in my case 4-7 PSI for the Holley 2300. If you were to try and use the fuel injection pump on a carbureted application, the fuel would blow past the needle and seat, flooding your carburetor. This article is going to focus on the carbureted application.

The next thing you need to do is figure out what volume of fuel you need from your pump. The optimal gallons per hour is calculated with the following equation:

Optimal GPH = (Max HP x BSFC)/(6 lbs./gal)

  •                BSFC= brake specific fuel consumption (typically 0.5 lbs./HP/hour @ wide open throttle)

My 1979 Jeep Cherokee in prime condition with the stock AMC 360 and Holley two-barrel makes a whopping 175 HP, so the calculation is as follows:

               (175 HP x 0.5 lbs./HP/hour)/(6 lbs./gal) = 14.6 gal/hour

This Summit pump flows at 35 gph, which is more than sufficient for my tired old AMC 360.

With that stuff out the way, let’s get to the install!

Choose a place to mount the pump where it is safe from getting hit by rocks, obstacles, etc. and away from exhaust heat. You also want to mount it lower than the fuel tank to create that siphon action. This pump needs to be mounted at a 30- to 45-degree angle from the inlet to the outlet. When attaching the ground to the frame, ensure that you clean the frame to bare metal to ensure a good ground. Lastly, make sure all fuel lines and wires are securely fastened and out of harm’s way. (Image/Josh Hahn)

It’s relatively simple, we’ll start with mounting the pump. You want to find a place out of harm’s way, that is lower than your fuel tank. What this does is aids in the self-priming action of the pump by creating a siphon to the pump from your tank.

The pump needs to be mounted at a 30-45-degree angle, with the inlet side lower that the outlet. I used the pump as a template, drilled the top and bottom holes, and used the supplied mounting hardware to secure the pump.

The plumbing is simple as well. You want to use as much hard line as possible, using rubber fuel line only to connect the hard line to your tank, pump, and carburetor. On the inlet side of the pump, make sure to install the supplied pre-filter. It is recommended that you also use a filter just before the carburetor, especially on a vehicle with an older fuel system.

It’s a good idea to run a filter at the carburetor in addition to the pre-filter supplied with the pump, especially in an old rig with an old fuel system. There’s nothing worse than stalling out on the trail due to a plugged-up carburetor. Well, maybe there are a few things worse, but it still sucks! And it’s preventable! (Image/Josh Hahn)

Secure all fuel line away from exhaust and moving parts. I used zip ties for this of course, but you could get fancy with special hardware if you want.

Lastly, the pump needs power. There are several ways to wire up an electric fuel pump. For best results, see mounting and installation instructions here, and check out my install video below.

When it comes to the wiring, at bare minimum you need to have a fuse. If there are any issues with the electrical circuit, you want the fuse to burn up and not your vehicle, especially when there’s fuel involved. (Image/Josh Hahn)

In conclusion, this is a great fuel pump for most stock to mildly modified carbureted applications. It can also be used as a primer pump for your mechanical fuel pump.

Watch the installation and product review here:

I run my fuel pump on a switch. This allows me to prime the carburetor after it’s been sitting a while, as well as run the carburetor out of fuel if the Jeep is going to be down for a few months. Eventually, I would like to change this switch out for one with a safety kill switch that is easy to see and use for emergency situations such as a rollover. (Image/Josh Hahn)
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3 Comments

  1. Mavis Zou says:

    oh nice

  2. Very good. I am very proud of you, Josh. My oldest grandson. Your grandfather,Joe was an old time cowboy, worked on old JD, Fordson, and his first car was a Willis-overland, made into a racer about 1924. I worked, operated CATERPILLARs, trucks. Jess is fabricator, and loves his hotrod. so what your doing, runs in the family. Keep up the good work.

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