| Jeep Holley® Pro-Jection® Kits |
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The following describes my first hand experience in 1997 with the Holley Pro-Jection fuel injection
kit. The kit was purchased for a '77 Jeep CJ5 equipped with an AMC 304 V8
engine. My hopes were to cure all the off-road problems that occur with
carburetors: flooding, rough idle, hard starting on hills, stalling, etc..
The following describes the kit, installation, adjustments, and issues for
the Holley Pro-Jection product. |
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Index
The Kit
Installation
Initial Starting and Adjustments
Fuel System
Electrical System
Problems
My Jeep Today
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The Kit:
Purchasing the kit is the easy part. All you need is a local speed shop
that stocks the product and money. The kit is very complete, "I was
impressed". Just about every thing you need to install the product
is included with the exception of fuel line. All Holley Pro-Jection systems
require that you have a 4-barrel intake manifold (more on this latter).
You can get one of two throttle bodies: one with two injectors, or one
with 4 injectors. I opted for the 2 barrel throttle body because it can
handle up to 670cfm, which is more than enough air fuel mixture for my
small AMC 304 V8. Some of the items included in the kit are listed below:
- Throttle body
- Computer Module
- Fuel Pump
- Throttle body to intake manifold adapter plate
- All required wire and connectors
- Temperature sensor
- Installation manual
- Instructional installation video
At the time I purchased the kit, it was about $560 plus tax.
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Installation
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The installation was relatively simple, but requires a lot of pre-installation
preparation and installation time. I watched the installation video several
times and read the installation manual at least three times before opening
the hood on the Jeep. Doing so made the installation easy and it worked
correctly on the first try.
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One of the more difficult, and time consuming, parts of the installation
was installing a 3/8" return line. I purchased two 5 foot lengths
of hard line from the local parts store and bent it by hand, no bending
tool was required. I placed a "T" in the filler neck for the
return line exit, and ran the line along the frame rail on the passenger
side up to the engine compartment. Also, you must use high pressure fuel
injection rubber hose, at more than a $1 a foot, this could be a hidden
cost you did not plan for. This also implies that you may have to remove
your gas tank to replace existing fuel lines.
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The second most difficult part of the installation was finding an appropriate
location for the fuel pump. The installation instructions require the pump
to be located at or below the bottom of the fuel tank. On a four wheel
drive like mine, this would be a mistake because it would be damaged or
ripped off by the first rock, stick or large clump of mud it came in contact
with. So, I located mine in front of the fuel tank on the cross member
that holds the tank in position. This means that the pump will have to
be primed all the time, which is hard on the pump.
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The next step was to find a suitable location for the computer in the cab.
I had to fabricate my own brackets. It is important that the computer is
accessible to make adjustments, away from heat sources, and can not be
damaged by feet or knees when entering and exiting the vehicle. Mine is
located under the dash just right of the steering wheel. My foot comes
very close to the computer dials when entering the vehicle.
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The next step is to install the temperature sensor which is used during
engine warm-up. I placed a "T" off an existing manifold sensor.
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The final step was to punch a hole through the fire wall for the bundle
of wires, and install the throttle body. The wire connections are very
well documented, and the provided connectors make it easy to get all the
wires connected correctly. This is truly a four wire setup. You need to
locate an existing ground, run power wire, starting power wire, and tachometer
signal (negative side of coil). The power wires require you to install
a relay (provided with the kit) to make certain that you have maximum power
to the computer during cranking. The throttle body just bolts to the provided
adapter, which bolts to the manifold.
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One non-standard unordinary step was that I wanted to use my stock intake manifold (two
barrel). I ran a 4 barrel, 500cfm Edelbrock carburetor with the stock manifold
and a $20 2-to-4 barrel adapter for a year with excellent performance (for
a carburetor). Since the Holley Pro-Jection is completely adjustable, I
made an educated guess that I could tune it to run using the stock manifold.
So, I purchased a ¾" thick plate of aluminum and machined out
an adapter that can be attached between the stock manifold and the Holley
throttle body. I could have used the $20 2-to-4 barrel adapter if I purchased
the 4 barrel Holley throttle body. The only problem that occurred was the
engine would start to flood at full throttle at altitudes over 5000 feet,
which I could live with. When I backed off the throttle a bit, it would
run fine.
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I also purchased the closed loop kit for an additional $200. This option
makes the necessary computer adjustments for altitude changes. This required
that an oxygen sensor (included) be installed in the exhaust. Other than
that, all the wires connected directly to existing Holley Pro-Jection wires,
and an additional small computer had to be installed under the dash.
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Initial Starting and Adjustments
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For the initial starting of the engine with the newly installed Pro-Jection
kit, I set all the computer dial adjustments in the middle. Next, I verified
the throttle position sensor (TPS) for the correct ohms reading. When you
turn the key to the run position you should hear the electric fuel pump
run for about three seconds, then shut off. This is also typical for factory
fuel injection. Since the fuel line is not primed, I suggest that you turn
the key to off and then to run again (several times) to make sure the line
has good fuel pressure (about 12-15 PSI). A fuel pressure gauge is necessary
to test the fuel pressure. Next, you tap the gas peddle to set the fast
idle solenoid which is used for cold starts. The solenoid may need to be
adjusted. With pressure in the fuel lines, I checked for fuel leaks before
attempting to start the engine, every thing was fine. After a short prayer,
I turned the key to start with my foot off the gas peddle, and the engine
fired easily. I was very excited!
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The computer has 5 dials on it, two are for cold starts. One adjusts the
temperature for when the system will change to the normal engine warm circuits,
the other fine tunes the fuel air mixture during engine warm-up. The other
three dials are for the normal warm engine circuits: accelerator pump,
idle mixture, and full power mixture. Instructions on how to adjust these
are well documented, I had my system tuned in about 5 minutes following
engine warm-up.
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One problem I had was that the idle adjustment was nearly maximized to the
lean side and left me no room for adjustment at altitude when I needed
to lean the system out for the thinner air. All that was required was to
readjust the TPS, which changed the range of the idle adjustment so that
it was closer to the rich side. It is best to tune the system using a tachometer,
but, after some practice, I could tune it by ear.
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Fuel System
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For a bolt on product, it is fine, but there are some overall shortcomings
in the fuel system that you should be aware of. The first thing is that
my fuel tank is not setup for fuel injection. With a carburetor, it does
not matter if the fuel pickup sucks some air from time to time because
the carburetor gets its fuel from its own built-in fuel bowl. This is not
the case with fuel injection. If the fuel pickup in the tank sucks some
air, your engine will stall. A fuel injection tank has a sump in the bottom,
which provides fuel for the fuel pickup at all times, even when you are
low on gas. Without the sump, the fuel pick will suck air when you are
low on gas, especially when going around corners and all the time when
off-road. I was running out of gas with 5 gallons still in the tank.
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The next fuel issue is the location of the fuel pump. The best location
for the fuel pump is in the fuel tank. This is where it is located on nearly
all fuel injected cars and trucks. The fuel keeps it cool, it is located
right at the fuel source eliminating the line priming problem, and it is
away from the elements that could damage it. The disadvantage is that the
fuel tank must be removed to service the fuel pump.
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Another problem involves the power connector for the provided fuel pump,
it proved unreliable. It is a clip on style and tends to work loose. This
should be a solid, bolt-on connection with a lock nut for off-road vehicles.
I was under the Jeep re-connecting the fuel pump power connector on many
occasions. The connector would not fall off, it would just back out to
the point were the electrical connection was not adequate.
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Electrical System
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Your electrical system must be in excellent condition to support fuel injection.
If you have a shaky alternator, a battery that always needs to be recharged,
and a lot of old wiring that has been spliced and crimped 10 times to many,
you will not be happy with your new fuel injection kit.
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I had a new battery in the Jeep that was destroyed after driving down a
long washboard road. From that moment on, I had to be jump started through
the entire week of my vacation in Moab. The battery had enough juice to
crank the engine, but not enough voltage to allow the computer to operate
correctly. With a carburetor, the engine would have fired every time. So,
this could also be a hidden cost that you were not counting on. I fixed
the battery problem by replacing the bad battery with an Optima jell cell
battery. The washboard roads won't kill a jell cell battery.
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I also would like to share an experience concerning alternators and fuel
injection. This has nothing to do with the Pro-Jection, but it still applies.
I have a Ford F-350 that I use to tow my Jeep. On one of my trips to Moab,
the alternator in the truck burned up, and I do mean caught fire. We were
just past the Interstate 15 and 70 intersection in Utah, which is in the
middle of nowhere. I cut off the wires connecting the alternator and removed
the belt that runs that alternator and smog pump. From there, I was able
to drive all the way to Moab with the Optima battery (5 hours). We jump
started the truck to reserve juice along the way and did intermittent quick
charges. So, I am convinced you can drive a fuel injected vehicle without
an alternator as long as you have a good battery. One note to make is that
once the voltage starts to drop bellow 11 volts, you only have minutes
to pull over before the computer stops the engine for you.
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Problems
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The Holley Pro-Jection system ran reasonably well for the first 6 months.
After that, more serious problems began to surface. The beginning of the
end was during an off-road trip to the Los Coyotes Indian reservation.
Half way there, my engine stalled on the freeway, I has able to nurse it
off the freeway and into a gas station parking lot. After about 20 minutes
of analyzing the problem, I discovered that one of the fuel injectors was
flooding the engine, it was literally dumping quarts of raw gas into the
intake manifold. We disconnected the injector and got the engine started.
The power was week, but it was enough for me to try to drive it home. My
friends followed my for a few miles, then I asked one of them to check
if they could see any smoke because something smelled funny. He said it
looked fine, then 10 seconds later he told me to pull over because I has
on fire. Apparently, there was raw gas in the muffler, and when the catalytic
converter got to operating temperature, it set off the gas fumes. I have
a 3" exhaust, and witnesses say there was a four foot long, 3 inch
round torch flame coming out the back of my Jeep. Being that it was night
time, it looked pretty cool. We didn't get home until 5AM, so totally disgusted;
I parked the Jeep and saved the analysis for another day. The failure was
actually the ECU (Electronic Control Unit, or computer). I switched the
injector caps and the other injector went to flood mode while the suspected
injector worked fine. I contacted Holley Technical Support, and, with some
measure of resistance, they agreed to test the unit and replace it if I
was correct (they replaced it). Now, the new problems began.
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The replaced ECU had an inherent problem. Whenever I used my CB radio,
the engine would stall. The old ECU never had that problem. I called Holley
Technical Support again and they told me to relocate the CB, or the ECU,
and to shield the tachometer wire. I told them that the old ECU had no
problems and that I wanted another ECU. The 3rd ECU had the
same problem, and later I came to find out that this was an common problem
that they were hiding from the public and had no intention of correcting
it. Holley is not like GM and Ford where they can be forced to do a recall.
So there I has, stuck with a bad computer. A friend of mine, who is an
electronics engineer, bought $5 worth of parts and minimized the problem
greatly using 40 year old electronics technology. At this point I lost
all respect for Holley.
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I know that some of you may be skeptical and think that I simply needed
to re-wire my CB, let me set you straight on the extent of this problem.
I completely remove the CB and CB antenna from my Jeep. My friend pulled
beside me and fired up his CB. His CB stalled my engine! A CB, not
installed in my Jeep, stalled my engine. This is unacceptable. My personal
opinion is that the Holley Technical Support personnel were told by their
management to blame the problem on the customer, rather than do the right
thing by offering a refund. My opinion is based on the immediate resistance
that I received from the Holley Tech support personnel when I first mentioned
the CB radio problem. Just imagine, you're driving down a remote mountain
highway, you pass a semi truck on a long curve, the truck operators fires
up his CB, your engine stalls, you spin out of control and die after falling
1000 feet down the rocky mountain ledge. Does Holley care? Apparently not,
they got the $800 bucks out of you before you died! This problem is very
well known (NOW!) in offroading circles and most fwd'ers prefer to avoid
the Holley system.
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My Jeep Today
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It has been nearly two years since I purchased the Pro-Jection system which is
currently installed in a box in my garage (it seems to work best in a box
in the garage). Holley has 800 of my hard earned dollars, and I still have
a carburetor in my Jeep. The last time I used the fuel injection was on
an off-road trip and the system worked fine the first day. I pulled into
camp to get a sandwich and the Jeep would not start again. Being well prepared
(now that I know about Projection), I had a carburetor bolted to the fender
well under the hood of the Jeep and a low pressure fuel pump installed
next to the high pressure fuel injection pump. In about an hour, I switched
over to the carburetor and finished off the weekend. I have been using
that carburetor ever since, and I have not had a problem since then either.
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Don't get the wrong impression, I still have a great desire for a fuel injected Jeep
(more on this in a future article). I consider this an $800 lesson that,
the only way to go is to use FACTORY, FACTORY, FACTORY products that run
on thousands of cars and trucks. Parts that can be purchased and replaced
nearly anywhere. Parts that have been proven by the test of time and designed
by competent engineering. The only words I have for Holley are "Stick
to the carburetor and throttle body market, stay out of auto electronics!".
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1997