By Jake Morton
many of us with 1994-1997 Ford Power Stroke Dieselís, there is a limit
to how much horsepower we can make. In 1999, Ford redesigned some things
and power levels went up considerably, especially when adding
aftermarket devices. For a long time, all the early Power Stroke owners
could do was a chip or programmer, exhaust, and an air intake. Anything
else was just out of the question, price wise, for most hobbyists, daily
drivers, and do-it-yourselfers.
flow fuel injectors have been around for a long time, but with price
tags ranging from $1000-3000 per set, they stay out of range for a lot
of folks like me. Enter Jim with DIY-injectors.com.
has developed a kit for the 7.3 liter Power Stroke, complete with step
by step instruction and photos, which will allow you to rebuild and
recalibrate your factory injectors for higher flow and performance, for
a fraction of the price! In fact, for a little more than the cost of one
replacement injector at the dealer, you can rebuild and recalibrate all
eight of yours, provided they are in good shape to start with! The only
special tools that are needed are supplied with the kit, other than
that, only basic hand tools are needed. The kit also contains all
necessary internal and external o-rings needed to rebuild a complete set
of eight injectors. The only part you will have to do is have one
internal piece machined to get the extra flow, or, if you like,
DIY-injectors.com can supply these parts as well for an extra charge.
If you can overhaul the carburetor on your lawnmower, you can rebuild
Letís get started!!
Our test truck is a
1997 Ford F350 with an automatic transmission, four inch exhaust, open
element air intake, intercooler, and an aftermarket chip programmed
specifically for larger injectors. This truck in stock form put down 164
horsepower, uncorrected, at an altitude of 5280 feet.
if you have never removed your valve covers and injectors, take some
time and read the Service Manual or do some research on the internet, it
really isnít that hard. You will need some extensions and wobbly sockets
to reach the rear valve cover bolts. Once you have the covers off,
remove the injector harnesses and valve cover gaskets and set them
aside. Remember that the Power Stroke valve cover gaskets are reusable,
so donít throw them away! Remove the top bolt on each injector, slide
the clamp off of the lower bolt, and you can pry the injector out of the
bore. It may be necessary to remove the injector oil spout from the top
of the injector prior to removing the injector, I found it easier this
Remove the first
injector and overhaul it according to the supplied instructions. Make
sure you have a clean area! Injectors and dirt do not mix well!
Disassemble the injector per the instructions, clean everything
thoroughly, and inspect for broken nozzle springs or a scored barrel and
plunger. If the barrel and plungers are scored, you can get replacements
through DIY-injectors. All of mine checked out fine so I was able to
reuse all factory components.
Replace the three
internal o-rings, clean the nozzle and youíre ready to reassemble. When
reassembling, you will either replace the intensifier piston with a
shorter piston, or have yours machined to the spec provided with the
kit. The intensifier pistons are the key to recalibrating the injectors.
Factory injectors flow
around 95ccís of fuel per shot, the DIY-injectors, when finished, will
flow a whopping 160ccís! Again, we chose to purchase the pre-machined
pistons so that we could have everything needed and not have to
disassemble all eight injectors at once and run the risk of losing parts
while waiting for the machine shop to finish up our pistons. Finish the
reassembly and install the external o-rings. Lube the outside of the
injector and youíre ready to reinstall!
Now is a good time to
replace the glow plugs, since you already have the valve covers off and
it will be necessary to remove the glow plugs later. Move on to the
next injector, and the next, until youíve rebuilt all eight. Once you
have rebuilt and reinstalled all eight injectors, remove all eight glow
plugs. Set the valve covers in place and secure them with one or two
bolts. Using a remote starter or just a plain old screwdriver, jump
across the starter solenoid and crank the engine for about 30 seconds to
evacuate all of the fuel and oil from inside of the cylinders, if you
donít do this, you will almost definitely hydro lock the engine and it
will not crank. Do this two or three times, and then reinstall the glow
plugs, wiring harness, valve cover gaskets, and valve covers.
Crank then engine and
fire it up!! It may take a little while before it will start but this
is normal since youíve drained the oil and fuel rails by removing the
injectors and it will take a little time for them to refill and start
firing the injectors. Be ready for a lot of smoke on initial start up
and on the first test drive! There will still be a lot of oil in the
cylinders so itís going to smoke like youíve never seen it smoke before
until all of the oil gets burned out.
It may take 20-30
minutes of driving to get all of the air out of the fuel and oil system,
after that, normal drivability should return and the engine should stop
smoking. By now, you should be feeling a seat of the pants difference
in acceleration! While these injectors by themselves will give you a
modest increase in power, the most gains will only be seen with a custom
chip programmed for larger injectors. An aftermarket intake, exhaust,
and gauges (especially a pyrometer) are highly recommended, especially
if you are going to be towing.
Daily driving is
wonderful, the engine idles smooth and accelerates normally under normal
conditions. Fuel mileage hasnít suffered at all as long as I can keep my
foot off of the floor! When the pedal is to the metal, watch out! At
wide open throttle, the larger injectors take over and the truck takes
off like a rocket! Off idle, acceleration is much improved and the truck
pours out thick black smoke until the turbo catches up! Did I mention
that turbo boost was at a maximum of 16 psi with the stock injectors?
Now it is close to 30 psi! Exhaust gas temperatureís stay in the normal
range, even when hot rodding the truck.
We ran the truck after
modification on a Superflow Dyno and we are now putting down 322
horsepower to the rear wheels!! Keep in mind that this is also with the
custom chip. Unfortunately we werenít able to get any torque numbers at
this time, the dyno operator didnít have the correct cables to hook up
to the truck, so we will have to settle for the horsepower figures only
at this time.
modification had me pretty apprehensive at first. I really wanted
modified injectors, but I didnít want to ruin mine in the process. With
the DIY-Injecors.com, this is not a worry. Each step was very well
described and the pictures proved invaluable! The first injector took
me about an hour to overhaul because I was following the instructions to
the letter and studying each photo. Each injector after that only took
about twenty minutes.
Thanks to Jim for
putting together such a great kit for all of us who want more out of our
trucks, but donít have the funds to buy off the shelf injectors.
DIY-Injectors.com also has a kit for the 1999-2003 trucks with the
split-shot style injectors. They offer a basic kit to overhaul only and
keep them stock, and can even custom build a kit to flow almost whatever
you want. If this seems a little overwhelming, you can also send your
injectors to them to be rebuilt and sent back!
If power is what youíre
looking for, DIY-Injectors.com has the answer! Please visit them at
www.diy-injectors.com and tell them the guys at MrTruck sent you!