The recent club road trip exposed
a few problems on the buggy. The first was a failing alternator. In the
past I had experienced issues with the motor cutting out at wide open
throttle. I have since replaced all sorts of sensors, a fuel pump, added
grounds, swapped ignition modules and tried disabling the boost bypass valve in
order to narrow down the culprit. The hills at the cinders in Flagstaff turned
out to be a great diagnostic tool, due to the inclines and altitude the engine
was working hard and consequently I had all three cooling fans running full
speed most of the time. This heavy electrical load exposed the dying
alternator when the buggy stalled while trying to climb one of the hills, a
lucky glance at the voltmeter at that moment showed 8V. After having the battery
test good that evening I bought a new alternator and haven't had a hesitation
I had my doubts that the
alternator was the problem because I had never seen the voltmeter dip below 12V
when checking it. The moral to the story is if you are not seeing 14V when
charging you may have a weak alternator.
The next issue involves my fuel
system. I re-used all of the lines and parts from my last setup but missed one
important part, the fuel lines I used for connecting the in-tank fuel
pickups were not rated for submersion in gasoline. I admit I asked the
parts counter guy if the hose in question would work in a fuel tank and he said
yes which is partially true. Almost any hose will work but for how long?
As it turns out the particular brand I bought lasted about two years before the
gas permeated the outer layers causing the hose to collapse. I also found
chunks of a gooey substance in the tank, another by-product of the hose break
So this go around I did some
homework and discovered I needed a hose that met the SAE 30R10 rating which
states the hose "is capable of handling fuel, alcohol-extended fuel or
diesel fuel in fully immersed, mobile, stationary and marine applications."
It turns out this stuff is not
common and even Gates primarily sells it to oems. I did eventually
discover a part number, Gates #27093 gets you a 12" long piece of 5/16 fuel
hose and it is available online from Napa and Checker although you should expect
a few weeks wait to get it as they don't readily stock it.
My fuel pickups also looked a
little worse for wear, you can see all the black bits of material caught in the
screen and I suspect the darker portion of the screen is also partially blocked
with even smaller particles. When I went to order new pickups I discovered that
there is a new revision of the pickup, P/N MP-10 has been replaced by
MP-12. The -12 pickup has a larger mesh than the older -10 (70 micron vs.
30). This change was brought about due to new formulations of gasoline
over the years that caused a residue build up in the plastic tanks these pickups
were used in (primarily snowmobiles). Auto
Performance Engineering is now also recommending you have at least one
pickup in the system with a bleed hole (P/N MP-13), this is in case the pickups
all get shut the bleed hole will allow them to open up quicker. Without
the bleed hole it could take a long time depending on how much vacuum the fuel
pump has pulled.
Since my pickups did not have a
bleed hole I suspect I experienced some of this "pickup lock" as the
mesh got filled with debris.
So the first step in my fuel
system re-fresh was to pull the fuel tank and clean it out real good to remove
any of the broken down hose goo and fuel cell foam debris. Here is a list of the
components in order that will go back into the system starting inside of the 8
gallon RCI fuel cell:
2 Fuel pickups, # MP-12
& MP-13 connected with 3 pieces of the ##27093 gates submersible fuel
The fuel cell is connected to a
low pressure 30 micron fuel filter (Summit # EDL-8130) via some 3/8" fuel
line (doesn't have to be EFI hose as this is the vacuum side of the fuel pump
but I used EFI rated hose anyways).
The fuel filter feeds an Vortech
VOR-8F002-265 (Summit Racing) 70gph, 85psi inline fuel pump. I suspect my
old MSD-2225 (Summit Racing) would have worked fine but due to the fuel lines
breaking down I thought the MSD pump was not providing enough flow (it is rated
for 43gph). I am hoping the old fuel pump is ok, it was pretty loud in Moab but
I suspect that was due to it trying to pull fuel thru the clogged
pickups/lines/filters. If it is toasted I have another MSD-2225 I plan on
After the fuel pump everything has
to be pressure rated, so for hose I am using some EFI fuel line I purchased off
of e-Bay. The line meets the SAE 30R9 standard (high pressure & high temperature) and cost about $2.80 a foot. The next component in line is a
pressure rated 5 micron fuel filter #MAA-3160 (Summit Racing). I did not
have this second filter in the system before but should have to further protect
the injectors from smaller particles.
So to sum it up, a decent fuel
system for a buggy that will support 3-500 hp will run you roughly $500 and
change. You could save a little by buying generic fuel filters off the
shelf but either way do it right the first time to avoid damaging more expensive
While in Moab I hit the scales
just south of town and discovered the buggy weighed 3700lbs without water in the
tires. With water in the front tires (filled halfway) the buggy weighed
4095lbs. I still need to weigh the tools and spare parts I carry but I'd
guess with a full cooler I have about 80lbs of cargo onboard. I thought the
buggy crawled and climbed better with water than without so I guess lighter is
not necessarily better.
And finally a quick update on tire
wear. The 9 day road trip put more wear on my tires than the last 30
outings here in AZ combined, but to be fair the rock in Farmington and Moab is
like sandpaper. Anytime you spun your tires you could see a small black
cloud of tire dust which symbolized a few miles of life coming off the tire. I
am hoping for over a year of tire life and I think it will happen. As you
can see the lugs are starting to get the typical chamfer often seen on comp
tires and this is how they work best. Seat of the pants tells me the grip
is getting better but still not quite on par with the bald Krawlers everyone
else on the trip were running. If tire grip can only get better I am totally
satisfied with these tires.
Update 4-24-07 - So maybe I didn't
escape major carnage on the road trip.
This is the short side axle from
my rear end. Basically an alloy 35 spline axle that most people said
wouldn't break. It broke on Saturday as I attempted a climb on Saw. It was
either a fatigue break or I twisted it on the road trip because It sure didn't
seem like it should have broke at the time. The long side also has a slight twist in the splines so I went
ahead and replaced both with another set of Dutchman alloy axles.
I also had to file down some of
the splines on my spool on the broken axle side. In hindsight I should
have stopped and pulled the broken axle before driving back to the trailer as it
looks like splines got a little chewed up from the broken bits grinding around in
My fix for the leaky diff covers
is holding up well. Here you can see I had to cut away the reinforcing
plate to remove the diff cover, a small price to pay to be leak free.