This write up is for the AFS Big Dog Fuel System with Walbro GSL 392
pump on a 98.5 - 2002. The kit comes complete with everything you need
to install on your truck so long as you still have the original fuel
module and not the in-tank lift pump. If you do you will just need to
install a Draw Straw.
First Thing I did was position myself underneath the truck between the
bed and frame by the back wheel. You need to get to get your hand up
under the bed and remove your Fuel Supply Line from the fuel module.
This is the larger of the two lines and should be the one towards the
back of the truck when looking at the fuel module. This can be a pain,
but it can be done. There are tabs on the top and bottom of the fuel
line that need to be "collapsed" so the fuel line can slip off. If all
else fails you will have to drop the tank or you can cut the fuel line
in front of the tank and start your install there, but I was able to
get mine off. Once the fuel Line is off you need to remove the plastic
clamp on the fuel module.
Next I headed to the front of the truck to remove the ECM connection at
the lift pump. Your Lift Pump is Located just below the Fuel Filter
Canister. Look for a grey connector - Push down on the clip and pull it
apart. Now unhook the fuel line at the inlet to the fuel filter and
remove the fuel line from the lift pump. Next you can unbolt the lift
pump from the bracket and get the source of all your troubles away from
your truck. Make sure you leave the bracket attached to the engine.
Now from your kit you can install the Metric Adapter and 90 Degree fitting into the inlet of the Fuel Cannister.
Next you need to mount your relay and circuit breaker and hook up the
pink trigger wire to the OEM connector for the lift pump. I waited till
the end to hook up the + & - to the battery. The kit includes cable
ties and velcro to mount the relay and circuit breaker. I chose a sheet
metal screw for the relay and mounted it to the firewall and a screw,
lockwasher, and nut and mounted to the "shelf" by the hood spring.
Next step is to Mount your pump. Start by mounting the bracket. You
will have to remove one of the fuel line clasp. Choose the one that
best fits your application. Re-use the screw from the fuel line clasp
to mount your bracket. Now you are ready to slide the pump into place
and mount it with the rubber clamps. The sticker on my bracket is
actually from chrysler. That is the sticker they are supposed to
install when the put the intank pump in. It says Caution: Fuel system
has been modified from it's original form. I thought it was quite
"fitting" for my application.
Now you are ready to run your fuel line. I figured a length to go from
the fuel module down to the pump. I tucked my fuel line inside the
frame and "fished" it down towards the pump. Attach fuel line at the
module. Next put your pre-filter in, then you need a small piece of
line to go from the pre-filter to the fuel pump. Next you can figure a
length to go from the outlet of the pump to the inlet of the filter. I
chose to run the fuel line inside the frame rail and right up to the
fuel filter cannister. I found it easier to remove the Push-lock
fittings and attach them to the fuel line then connect. Now you can run
your red & black wires from your relay back to your fuel pump. I
ran them through the frame also. Hook up your pump. Red is +, black is
Back up underneath the back of the truck to cut the Fuel Fill Line.
Instructions say to remove it, but I had great success leaving it
attached and using a small hacksaw to cut it, and install the "Tee" so
I didn't have to remove it. Now you can figure a length of line to go
from the "Tee" you just installed to the Fuel Pump Return.
Now hook up the the 2 connections at the battery from the relay. Double
check all fittings and connections. When you are satisfied - bump the
starter and let the pump cycle - double check for leaks - if everything
is ok - go ahead and bump the starter to cycle pump one more time then
try and start. If your engine does not start you may have to crack an
injector or so to bleed any air from the lines.
Check your fuel pressure gauge to determine if fuel pressure is
adequate. If not you may have to adjust the bypass regulator. When I
started my truck up it carried 16psi at idle - so I didn't make any
That's it - I had about 3.5 hours in doing mine with some help from my
dad. We did a lot of double check and taking time to do it right.
A lot of the kit comes pre assembled like the fuel pump, regulator and
relay wiring harness. It also has a good set of instructions including
some black and white pics - overall a very nice kit for the money.
Check out http://wideopendiesel.com/page8.html
for more info - Jason will be happy to help you
Hope this helps someone