Multi Port Injection

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Before After


This project is the ultimate solution for your stock Carter BBD carburetor and all its inherent problems.  You've probably heard about these conversions before.   There are a few websites out there that discuss these conversions - I know, I've looked at most of them - and if you're considering this conversion for your own Jeep, you are probably looking for some information on "what's involved."  The following is my cut at the subject.  I believe there cannot be too much information on such a significant project.  I will show you what I've discovered along the way through the process of converting my Jeep's fuel intake over to an electronic fuel injection system.  Enjoy.

What Is It?

This kit is not the cheapest way to install fuel injection onto your Jeep, but it is the way Jeep does it for their own vehicles.  The Mopar MPI kit is based from a 1994 (sometimes I have found references to a 1995) YJ 4.0 liter motor.  All of the parts included in this kit come from Mopar (Jeep) and can therefore be serviced later at any Jeep dealer.  To me, this was a very important issue.  Why?  Because if I ever decide to sell this Jeep, I can prove this a Jeep-serviceable vehicle and not some home-made conversion job.  If I ever need help servicing it, I can take it to a Jeep dealer.

The other common kit for California Jeeps (who have to pass Smog Inspections for registration renewal) is the one offered by Howell.  I have also installed one of these kits on another (1985) CJ.  The Howell kit is a Throttle Body Injection (TBI) system, based on General Motors (GM) parts.  That kit uses the stock intake manifold to deliver the fuel/air to the cylinders, so there is a considerable savings in the kit (cost wise) as there are fewer parts.  The TBI mounts in the location of the carburetor, and delivers fuel through two computer controlled jets.

Both kits do away with much of the vacuum controlled systems, which is the source of many poor idling and stalling performance problems.  But since this page is about the Mopar install, I am going to ignore the Howell kit for now.  At the bottom of this page is a link to my Fuel Injection Comparison page!

Before You Order A Kit!

This may be totally obvious, but just in case, before you make such an investment first make sure your Jeep's motor is not suffering from other significant problems.  I recommend doing a compression check to help see if your motor has some life left in it.  Poor compression could be a sign of several internal engine problems that may be troublesome.

Conversely, if your Jeep's motor has been significantly modified (performance cam, bored-over cylinders, ported heads, headers, etc.) you may want to do some more research into the kit before buying.  The Mopar kit is a "one-kit-fits-all" assembly and is therefore set up for the "normal" Jeep motor.  Fine tuning of the injectors or tweaking of the new computer may be necessary if your motor is in the high-performance category.

My motor has 160,000+ miles on it!  However, I have taken pretty good care of the motor and the compression has checked out.  I am very satisfied with the overall performance of the 258 motor and have no intention of going to something bigger.   So when the time ever comes, I plan on placing a new 4.2 liter block under my aluminum valve cover, Borla headers, and new Mopar MPI system!

What You Need To Know...

When you order the Mopar MPI kit, there are two things you need to know.   The first is whether your Jeep has an automatic or manual transmission.  The second is whether your Jeep has a serpentine belt drive or a V-belt drive.  Assuming you know those two things, you can successfully order your kit!

FIRST ADVICE:  Plan on replacing a few other things along the way!   This means, have a contingency in your budget for new parts or tools.  While I am thinking about tools, here are a few tools that will be handy for this job:  air compressor, impact wrench, a die grinder, a bench grinder, a small tubing cutter, a flairing tool, a harmonic balancer puller, a gear puller, and a drill.

Most of this project is fairly straight-forward.  It was quite intimidating for me when I started, but as things got going, most of it became rather obvious.  Keep in mind, there will be LOTS of modifying and customizing things throughout this project!  Once you accept this, it will be easy.

Getting Started!

These steps will generally follow the instructions included in the kit.   However, I will take the liberty to explain some of the things the kit's instructions fail to mention in much detail.

Take inventory of all the parts!!! Step O-1  When the kit finally does arrive, find the sealed manila envelope that contains the instructions, decals, and parts list.  Remove the parts list and take some time going through all the parts to make sure they're there.  Also, get familiar with what you have and visualize how it all goes together.  But be very careful not to open any plastic sealed parts at this time!  (Okay, I did this in my bedroom since it was snowing outside!)
Step O-2 Read the instructions AND the included Tip Sheet.  I found it helpful to mark those steps in the instructions that had a corresponding tip with it on the separate Tips Sheet.


Step D-1 As with most projects under the hood, it is always recommended that you disconnect the ground cable from the battery to avoid inadvertently shorting out an electrical component somewhere else.  Also, drain the coolant from the radiator.
Take note of the order of the power steering pump mounting brackets. Step D-2  Next is the removal of the fan belt.  To do so, loosen the power steering pump and/or the alternator.  (Note:  For me, I needed to remove the alternator for another reason, and I found it easier to just remove the power steering pump and get it out of the way, so I did so at this time.)  I took this photo for myself so I could remember the order of all the brackets that hold the pulley wheel and pump.  If you have a camera, or a felt pen, it helps to take some notes (or write on the parts and note their direction).  Remove all the brackets for the power steering pump.  The rear power steering bracket that mounts to the intake manifold will be needed later, so do not discard this part!
Remove the aircleaner and carburetor Step D-3  Remove the air cleaner assembly (and all the junk attached to it) and the carburetor. 
Early yardsale. Step D-4  This will be the time to start your bone pile.  I recommend keeping all the discarded stuff in a pile until you're finished.  Later on, you may be looking for small parts to help customize things and the pile will be a great source of metal fasteners and such.
BBD-flush. Step D-5  The one exception to the bone pile rule in Step D-4 above is the Carter BBD.  This thing needs to be ceremoniously discarded.
Step D-6 Now the fun really begins!  This is the step where you start the removal of the "production emissions controls from the engine" according to the instructions.  This includes all the vacuum solenoids atop the valve cover, vacuum lines, and so forth.  Hmmm, not too much information here...  What exactly are all the emissions controls? 

However, the Tip Sheet mentions that you can either remove the old computer from under the dash, or cut the computer wires off at the firewall and stuff them through the hole!

Here's where the old computer hides. Step D-7  I figured if you can "cut the wires" then anything attached to that wiring harness is not going to be needed.  So I recommend starting from the computer and working your way out along that one wiring harness (there are actually two separate wiring harnesses on the stock Jeep) and remove anything attached to it.  To access the old computer, remove the glove box.  One screw holds the computer to its bracket, and another holds the wiring plug to it.
Step D-8 Now the computer wiring plug can be pulled through the firewall.   (You'll need to unscrew the rubber cover over the large diameter hole for the plug.)  Any plug that is attached to this wiring harness leads to an item you will no longer need.  Remove the plug and discard the harness.  Then remove all the parts that were attached to it and add to the bone pile.

Hint:  The ignition module (mounted on the back of the front fender well) has wires attached to it from both wiring harnesses.  This part will no longer be needed and the plug from the other wiring harness (that will remain) can be cut off.

Step D-9 Remove the pulse air valves and their metal tubes that connect them with the catalytic converter (downstream) and the header pipe (upstream).  Note:   Later these ends (on the header and catalytic converter) will need to be sealed.   Add parts to bone pile.
Step D-10 Disconnect the heater hoses from the intake manifold.  Remove the old throttle cable (from the gas pedal) and feed it through the fire wall.  Remove the intake manifold, which will require removing the short "S" shaped tube that runs from the EGR valve on the bottom of the intake manifold to the exhaust pipe (hint: a 1" open end wrench will be needed). Don't discard this short tube, you will later need part of it.  Also, if your Jeep is so equipped, you will have to disconnect the brake booster brass fitting from the old intake manifold.

Tip:  Technically, the exhaust manifold can remain on the cylinder head during this project.  However, since you're this far along, I'd recommend installing a new exhaust gasket (not included with the kit) later during the install process.  For now, after the manifold is removed, place the bolts back into their original places on the head so they won't get lost!

Step D-11 Over to the other side of the engine, remove the hose clamps and the short rubber hose from the main fuel line going into the mechanical fuel pump.  This is (or will become) the main PRESSURE fuel line.  Then remove the fuel pump and toss on the pile.
Remove the radiator and fan. Step D-12  Now the radiator and shroud needs to be removed.  This involves removing both the upper and lower hoses.  Also, remove the thermostat housing, thermostat, and the engine fan.  ONLY if you have a V-belt motor, you need to remove the crankshaft pulley at this time.
Step D-13 Remove the plug wires and all the spark plugs.  If you're going to re-use the plugs, keep them in order!  Pull off the distributor cap (noting where the Number 1 cylinder wire is located), but leave the rotor on.  By the way, the Number 1 cylinder is at the front of the motor!
TEST 1 Now comes the test for the timing chain!  Put a large ratchet on the bolt holding on the harmonic balancer, and rotate the motor around (clockwise) so the timing mark (on the balancer) is aligned with the "0" mark AND the number one piston is at Top Dead Center (TDC) on the compression stroke.  It should be there when the rotor on the distributor is pointed at the location of the Number 1 plug wire, AND the timing mark is resting at "0".  It will be much easier to have someone looking down the Number 1 spark plug hole and watching the piston come up, too.

Once you've set the motor at Number 1 TDC, have your helper look through the place where you removed the mechanical fuel pump and watch the cam lobe.  Rotate the engine backwards (counter-clockwise) VERY SLOWLY until the cam lobe BEGINS to move and then STOP rotating the motor.  After you stop, note how far the timing mark on the balancer moved.   If the slack is more than 10 degrees (remember, 360 degrees makes a full circle) then it's time to replace your timing chain. 

NOTE!  Even if the slack in your timing chain is not too excessive, now will be a really good opportunity to change the timing chain if it hasn't ever been changed before.

Step D-14+



A look at the new distributor.

After TEST 1, return the motor to Number 1 TDC.  Then loosen the hold-down clamp and remove the distributor - pulling it upwards with a slight twist.  

Once the old distributor is out, look down the hole and note there is a grooved slot at the bottom.  This is the oil pump.  The instructions say to move the slot to the 11 o'clock position before installing the new distributor.  To move the grooved slot, place a long screw driver down the hole and move it accordingly.

The Tip Sheet recommends installing the new distributor at this time - before the motor moves from Number 1 TDC.  Don't forget to use the new distributor gasket at this time (located in the plastic bag in the small parts box).  Note there is a indexing lock pin on the bottom of the new distributor - do not remove this pin before installing the new distributor!  Once the new distributor is seated all the way down, replace the hold-down clamp and tighten the bolt carefully.  Now the indexing pin can be pulled from the bottom of the distributor.

Old coil mounting bracket. Step D-15  Remove the old coil and the coil mounting bracket.  This was almost impossible as the mounting bracket is attached with torx bolts that are not likely to be moving anytime soon!  Before trying to extract the torx bolts, loosen the screw in the back and use a hammer to lift out the oil coil (you are going to need it again, anyway).  Once it's out, then you can bend over the hoop and get a better angle at the torx bolts.  If that doesn't work, click here for a solution!
Pulling the harmonic balancer.  

Step D-16  Now the harmonic balancer can be removed.  An impact wrench works well for the extraction of the retaining bolt.   Using a harmonic balancer puller, remove the old harmonic balancer.  The face of the old harmonic balancer will probably need to be cleaned in order to get the puller's bolts installed. 

If you are planning on (or needing to) replace the timing chain, follow this link for what is involved in changing the timing chain.

Step D-17 Remove the windshield washer and coolant overflow bottles from the fender well.  This will expose the top of the charcoal fuel canister (evaporation canister).  There is really only one fitting on the old canister that is worth noting.  It should be green in color and the fitting runs back to the fuel tank.   Mark (or remember) the end of that hose.  You can remove the canister now, too.
The bone pile grows! Step D-18  Finally, remove the front three driver's side oil pan bolts and the oxygen sensor from the exhaust manifold and toss them on the pile.


* These steps differ in order slightly from the printed instructions!

Cutting the EGR "S" tube.  Nothing like having air tools!

Inserting the small freeze plug into the header.

Step A-1  First, find that "S" shaped EGR tube you removed in Step D-10 and look to see which of the two tube-nut ends is in the best condition.  Cut off the flaired end of the tube and remove the better tube-nut end.

Find the little silver disc (freeze plug) that's located in the plastic bag found in the small parts box.  Insert the plug into the exhaust header hole where the "S" shaped EGR tube used to be attached.  Seal the plug into the hole with the tube-nut end that you just removed.

Compair the new coil bracket with the old fuel pump.

The new coil mounting-plate has larger holes than the stock bolts for the mechanical fuel pump.  Shouldered washers solved the problem!

View of how close the new coil is to the alternator mount.

View of new coil after remount.

Step A-2  Next is the mounting of the new fuel pump block-off plate/ignition coil bracket.  The first photo shows the comparison of the new coil bracket and the old mechanical fuel pump.  You will need to use a new fuel pump gasket (which IS NOT included with the kit) for installing the pump block-off plate/bracket.  Add this to your list of parts.

The second discovery in this step reveals that the holes that are drilled through the block-off plate/bracket are larger than the stock mounting bolts.  Somehow, I not only found a shouldered washer in my garage that solved the problem, but I found a pair of them!

The third discovery came after I installed the pump block-off plate/bracket per the instructions and saw just how close the electrical plug fitting was to the alternator mounting bracket!

Knowing that this wasn't going to work, I looked at all the available room on this side of the motor and simply unbolted the coil from its bracket (it came pre-assembled) and flipped it around and bolted it back to the other side.  There is still plenty of room between the coil wire end and the distributor.  Now the electrical plug will fit into the other side!

Step A-3 Install the new harmonic balancer (dampener).  This will fit onto the end of the crankshaft only one way.  Align the keyway and press the dampener onto the crankshaft.  A few taps with a metal hammer may be necessary to get the dampener started.  Once it's on far enough, the mounting bolt (with the heavy washer) can be threaded into the crankshaft end and the dampener can be pressed on the rest of the way.   (An impact wrench really helps in this step!)
Modifying the pickup sensor mounting plate holes.

View of the mounted pickup sensor.

Step A-4  Mounting the pickup sensor bracket.   This bracket mounts where the three bolts were removed from the bottom of the oil pan in Step D-18.  On my bracket, the holes did not exactly align with those on the bottom of the oil pan lip.  I played with it and found I could get two of the new bolts in, but not the third.  I marked the area I needed to modify and placed the bracket in a vice and carefully enlarged the hole with a drill.

Once the bracket could be installed, the sensor was set against the new harmonic balancer.  The instructions talked about a paper button on the end of the sensor, but mine didn't have one and I had to use a feeler gauge (like that used for spark plugs).  Set a clearance of .020" and .060" between the sensor and the crankshaft dampener and tighten the sensor.

New thermostat housing doesn't fit!

New parts for the thermostat housing temperature sensor relocation.

After the adjustments!

Step A-5  Installing the new thermostat housing.   The new Mopar MPI intake manifold does not run coolant through it like the stock manifold.  On the stock intake manifold, the coolant temperature sensor is located Inside the stock intake manifold.  With the new system, the thermostat housing now contains the coolant temperature sensor.  Thus comes the next discovery: the power steering front mounting bracket (for some serpentine belt engines) prevents this fitting!

The Tip Sheet warns of this and the cure was fairly simple.  I had to remove the sensor from the housing, block the hole with a brass plug, and insert a "T" fitting into the heater hose just past the thermostat housing.  The sensor is now located in the "T" fitting.  The second photo shows all the parts.

With the brass plug installed, the new housing now (barely) fits into its confines.   With this set up, you may be able to use the stock housing.  But I needed to replace my old leaking thermostat housing anyway. The new system uses a 195 degree thermostat!  The thermostat, housing, and gaskets are all included with the kit.

View of new temperature sensor and radiator now installed. Step A-6  Install the radiator, fan shroud, upper and lower hoses, and heater hoses.  Both heater hoses now route directly from the front of the motor down the passenger side of the motor to the heater core (at the fire wall).  Hint: This is a good time to replace all those warn-out hoses and hose clamps if you still have them!
New gaskets for both manifolds. Step A-7  As tipped in Step D-10, this is a good opportunity to replace the exhaust manifold gasket!  This Mopar kit only includes a new intake manifold gasket.  A trip to three local auto parts stores told me I could not buy just an exhaust manifold gasket!  So I had to buy a SET of gaskets.   Still it is worth it to do this now while you're this far into the project.
New intake manifold installed. Step A-8  Install the new intake manifold.  Be very careful not to over tighten the manifold bolts.  Use your shop manual to see the tightening sequence of the bolts.  The bolt torque is 23 ft. lbs.
Photo showing excess power steering backing plate mount.

Power steering pump hoses are a tight fit!

Step A-9  Reinstall the power steering pump brackets, pump, and bolts.  Note in the top photo how the backing plate no longer attaches to the intake manifold.  The top part of that backing plate can be trimmed if needed or desired for a cleaner look.

You may need to bend the pressure tube hose from the power steering pump if it's too close (or touching) the intake manifold (see lower photo).

View of connected throttle cable. Step A-10  The throttle cable can now be installed.   First, push the end through the fire wall (from the engine bay side) and attach the round end to the gas pedal.  Then clip the plastic block into the hole to hold the housing.  The throttle cable will run near the back of the valve cover and over the top into the rear-most opening on the intake manifold bracket.  Hint:  Don't attach it just yet as you'll need to pull it out of the way when you run the new wiring harness down to the injectors.

Also, if you have an automatic transmission, the kick-down linkage would be installed at this time.

Step A-11 Reinstall the fan belt(s).  Tension the belt by adjusting the alternator outwards.  Make sure both the alternator and the power steering pump are tight when finished.
Note! There are two metal fuel lines provided with the kit, each with a quick-connector on the top end.  They look almost identical, except there are different color fittings on the quick-connect ends to distinguish them from one another.   If you pull the dust caps off and look inside the end, you will note one has a larger diameter O-ring inside than the other - this (larger) is the pressure line.   The other, with the smaller O-ring inside is the return line.  Make sure you use the proper lines in the following steps! 

Both lines connect side by side to the fuel rail (back metal tube on top of the intake manifold) at the forward end of the motor.  The top photo in Step A-9 above shows the two fittings on the fuel rail with colored rubber caps - where these fuel lines will eventually connect.  The colors of the two dust caps on the fuel rail were different than the colors of the protective caps on the fuel lines!  But it's not that complicated.

View of fuel line routed around the front of the frame (below the radiator).

View of modified in-fuel line.

View of bowed fuel-line from below.

Step A-12  Installing the high-pressure fuel intake line.  For the CJ models, the exhaust runs all the way down the driver's side frame rail to the rear (on YJs, the exhaust crosses over to the passenger side behind the motor).  Thus, there are two scenarios of fuel line routings from the tank to the motor in order to avoid the heat of the exhaust.  The provided fuel lines are set-up (bent) for the YJ scenario.

For CJs, the easiest way to route the high pressure fuel line (tank to motor) is to leave the stock hard-line system as is (to the passenger-side motor mount) and then continue it (with rubber high-pressure fuel injection hose) around the front of the frame (under the radiator as shown in the top photo) over to the forward end of the driver-side frame rail (to a location roughly under the power steering pump).  I had to buy 8-feet of this fuel line to complete this project (including the remaining steps).  This stuff is not cheap (about $6 a foot) so be careful with it!  Also, be careful when bending the stock hard-lines as needed.  Try to minimize the bending of the older fuel lines if you can (to prevent cracks).

The second photo in this step shows how I altered the provided (large diameter) fuel line by bending it forward (it will make more sense when looking at it in person).  I attached the rubber high-pressure fuel injection hose (routed from the other side) to this fuel line.  In the third photo, the connection between the two fuel lines will be made somewhere right behind that hanging plug!

Step A-13 Installing the fuel return line.  Connect both of the provided fuel lines to their respective locations of the fuel rail.  Then attach them to the hanger strap (installed on the new manifold).  The return line will naturally route down towards the frame rail near the rear spring hanger of the driver's side front leaf spring.

There, you will find the return line mounted to the frame rail.  Normally, this metal fuel line is wrapped with a spring to protect it.  The two metal lines will probably pass each other.  Cut the tubing of the frame-mounted fuel line to shorten its length accordingly (and flair the end of the cut piece).  Now mate the two ends of the fuel return lines with a piece of the rubber hose provided in the kit.  Use the provided hose clamps to secure the hose to the metal fuel lines.

Modifying (cutting) the stock fuel line.


Tubing cutter on the fuel line.


Flairing tool.


View of complete fuelpump to fuel filter to tank fuel line mounting location.

Step A-14  Installing the new electronic fuel pump and fuel filter.  This step made me nervous as this will be a likely source of leaks or problems.  This step also involves the most in the way of modifications and customizations!  The fuel pump and filter are mounted to the rear cross member just in front of the gas tank.  This step just shows how I came up with a solution to mount these parts.

I started by removing the strap/bracket that holds the fuel hard-line near its bend over to the cross member (on the passenger side frame rail end).  I then pulled (yanked) the fuel line out away from the frame rail (as shown in the top photo).  The second photo shows cutting the fuel line and the third photo shows flairing the end.

Next, move to the opposite side of the rear cross member where the fuel hard-line first comes from the top of the fuel tank over to the cross member.  Again, I cut the hard line a few inches after is rested against the cross member and flaired the end.

In between these two cuts, the fuel filter and fuel pump will be mounted.  A rubber coated strap is provided to use in mounting the fuel filter.  The fuel pump uses a special metal strap that is provided (with hardware).  Both the filter and the pump will mount to the cross member via the bolts used to hold up the fuel tank.   Those were fun to break loose!

I had to play with a number of combinations to make the two fit in order, and NOT result in a tight bend to the rubber high-pressure fuel injection hose.  I ended up making a bracket using a short piece of L-shaped metal and drilled holes in the ends to accept the cross member tank bolt and the fuel filter retainer strap.  It worked.   The fit is tight, but the rubber fuel line is straight.  I then linked the parts (keep in mind there is a specific fuel flow direction on each part) using the fuel line and lots of hose clamps.

(Hint:  The leads for the electronic fuel pump's wires are labeled + and - accordingly, but are hard to see.  Mark them with a felt pen so you can easily distinguish them later during the wiring.)

Stock mounting location of the evaporation canister - doesn't work!

Relocating the evaporation canister to the rear fender well using the stock mounting bracket.

Photo showing the drilled bolt locations for the relocated evaporation canister bracket.

Tight fit, but everything is there!

Step A-15  Mounting the new charcoal canister, the new Powertrain Control Module (PCM), and stock bottles.  Here's another step that requires some thought.  The goal is to get the charcoal canister, the new computer, the coolant overflow bottle, AND the windshield washer bottle all to fit in their [somewhat] stock locations.  It can be done but it is not easy!  My goal was aesthetically motivated as well.

The top photo shows the new charcoal canister sitting in the stock bracket in the stock location (even though a new canister bracket was provided).  The canister fits in the bracket, but it will sit too high and the PCM will not fit over it AND under the back of the fuse block.  The PCM can be mounted either vertically or horizontally, but I wanted it to be neat, secure, and out of the way.   So, since that was my top priority (and it had the fewest possibilities), I picked the PCM mounting location FIRST.

After the PCM spot was claimed, I then moved back to the canister and found that it would fit (using only the stock bracket) if it was relocated on the back side of the fender well.  But before I drilled the holes for that new location, I also had to check the stock windshield washer bottle (a new bottle IS NOT provided with the kit anymore).  The stock bottle is short, but its pump hangs off the bottom and interfered with the top of the canister.  However, I found if I twisted the canister slightly (to the 1 o'clock position) the pump lines would barely clear the canister (second photo).  Once all these were set, I marked the location for the new holes to hold the relocated canister bracket and drilled them from the tire side of the fender well (third photo).

The last photo in this step shows how they all fit together (three hours later).   The PCM, canister, and washer bottle actually have to all be installed as a unit (to allow them all to fit)!  (Hint:  Don't forget about the plug that goes into the PCM!!!)

PCM and first attachment of the wiring harness. Step A-16  Installing the wiring harness.  This step was actually fairly easy!  Start by connecting the wiring harness to the PCM (go back and remove the washer bottle again!) and then carefully routing the harness through, around, or over, the parts in the engine bay.  The kit comes with some tiny zip ties, so you'll need to get some larger ones.  Secure the harness along the way and take care to keep all the wires within the plastic sheath.
Install locations of Relays and MAP sensor (as wired). Step A-17  Mounting the relays and the MAP sensor.   As you're routing the harness, you will note there are a number of plugs and wires that pop out of the loom along the way.  Each of these wires and plugs are labeled to tell you what they are for and where they will connect.  Some of the first that you will encounter are the two relays and the MAP sensor that need to be mounted to the fire wall above the back of the motor.  This photo shows them mounted.

Note:  There are also wires here for the tachometer (if you have one) and a "Check Engine" light.  My CJ had neither, so I just stuffed those wires (leaving them labeled) back into the plastic sheath until I am ready to install either of these.  Check this sub-link to see information about the Self-diagnostic Codes used with the Check Engine light!

Routing the wiring to the front of the motor. Step A-18  Wiring to the front of the motor (along the fuel injectors).  Continue routing the wiring harness over the top of the manifolds.  There is a long plastic rail that clips to the valve cover bolts and it helps keep the wires out of harm's way (heat).  Each fuel injector plug is labeled to make it easy. 

Remember when I recommended to not connect the throttle cable back in Step A-10?  It will now be easier to lift the throttle cable and set the plastic rail (and wiring) down first, then attach the throttle cable to the throttle lever.   Check now to make sure the throttle pedal moves easily and is not bound anywhere.

Continue routing the wiring harness around the front of the valve cover.  At the front of the valve cover, connect the plugs that attach down to the pickup sensor, the coolant temperature sensor, and the oxygen sensor (which can now be safely installed into the exhaust header pipe).  Take care to make sure the pickup sensor and oxygen sensor wires don't come into contact with the exhaust pipes.

Step A-19 New plugs and wires.  The kit provides new plug wires, but does not provide new spark plugs.  Jeff, at Hesco, Inc. (the company that puts these kits together), recommends using a Champion RC9 YC4 plug for this set up (.035" gap).  Install the new plug wires (153624) and the coil wire.

Continue routing the wiring harness over the plugs, connecting the coil and distributor plugs along the way.  At this point, the wiring harness will shrink in size, and the remaining end will be routed over the top of the transmission toward the back of the Jeep (secure the harness as you go).

Installed speed sensor. Step A-20  Installing the speed sensor.  The speed sensor is attached between the end of the speedometer cable and the transfer case.   It basically just confirms for the PCM that the motor is moving and it is not indicating the specific engine speed.  So it does not matter if your speedometer is not perfectly calibrated.

Plug the wiring harness into the speed sensor and route the remaining end of the wiring back over to the passenger-side frame rail and back to the fuel pump.  Attach the last two wires to the fuel pump and secure the harness.

New valve cover top grommets.


View of brake booster brass fitting (installed) and the provided one (in hand).


A view of the various hose routing and air filter mount.

Step A-21  Hooking up the air filter, hoses, and last little wiring details.  

There are two plastic elbows that fit into the valve cover that are included with this kit.  They take the place of the old PCV valve and breather tube spots.  One elbow is gray and has a smaller size hole inside.   This is for the "CC valve" hose that connects the rear valve cover opening with the CC valve on the manifold.  The other elbow (black) is just an elbow for the fresh air breather, and it connects with the air cleaner/intake tube.  But both of these elbows are larger in size (1" diameter) than the original PCV valve and breather elbow.  I had to buy new grommets (shown in the first photo) to make them fit.  Most of the other hoses that attach between the charcoal canister, manifold, air cleaner tube, and valve cover will be sort of self-explanatory.

My brake booster fitting did not fit with the one provided on the manifold.  The fitting off the old manifold was too small to fit in the new manifold.  So I had to buy a new brass adapter to make this work.  (The large stock adapter is shown in my hand.)

Next, there are two wires that come from the relays mounted in Step A-17.  The red one attaches to the positive feed at the starter solenoid.  The yellow wire attaches to the hot (switched power) lead that went to the old coil clip.  Clip off the plastic coil clip (if it's still there) and mate these two wires together.

Finally, there is a 7.5 amp diode that is supplied with the kit.  This attaches to the field wire of the alternator (brown).  Clip the wire and insert the diode and crimp the ends.

After-view of welded air tube on header pipe. Step A-22  Remember those two air tubes left over from the pulse air system (exposed after Step D-9)?  They need to be sealed.  The instructions say to bend over the ends and crimp them!  I needed to replace my catalytic converter, so the new one I bought was already sealed.  While my Jeep was in the shop getting its smog check (and the new catalytic converter installed) I had them cut the tip off the header pipe and weld a seal over the hole.  Again, I was opting for the cleaner look.  Be creative here!
A VERY IMPORTANT STEP! Step A-23  To complete the conversion and make it legal, apply the provided CARB Executive Order D265-7 decals!  When you take your vehicle to get a smog inspection, this is one of the first things they will be looking for.
Step A-24 Reconnect the negative battery cable.
TEST 2 Turn over the engine and IMMEDIATELY check for fuel leaks.  The motor will crank for a short while in order for the fuel to reach through the entire system.   If all goes well, you should hear something pleasant!
Yardsale! Note!  This is a universal kit, meaning it is designed to fit on a number of engines between 1981 and 1990.  Therefore, there will be a few parts in the kit you will not be using.  I found most of my "extra parts" were those associated with the air cleaner/intake assembly (hoses, metal tubes, and brackets).  Here's a photo of the final bone pile!


The main reasons for installing the fuel injection kit onto my Jeep were to be able to pass my smog inspections and to have a Jeep that didn't die at every stop sign in the winter.  Two days after I finished installing