Carb Swap - Blow by Blow
Contributed By: Jeff Herbst
As requested: The Great Carb Swap 1997
It was a cold and rainy Saturday....
Note: this describes a 1982 Wagoneer LTD w/heavy duty cooling & A/C
others may vary.
- Carburetor: Edelbrock 1400 (emissions legal EGR 4V spread bore)
- Intake: Edelbrock Performer AMC EGR
- CAR: 1982 Jeep Wagoneer LTD, AMC 5.9(360cid), auto, A/C, Part time 4WD
- Carb, Manifold, Manifold gasket set
- Teflon tape
- Form-a -gasket (small)
- about 30 ft 3/16", 15 ft 1/4" and 10 ft 3/8 vacuum/gas line
- New PCV, thermostats and water temp sensor
- Any hoses that are questionable (replace ALL vacuum hoses)
- 1 1/4" aluminum stock 1"x4" ( or 2 1/8")
- Paper towels
- Large rags
Step 2. Tools
- 3/8 drive socket set
- 9/16" combo wrench
- Hose clamp pliers
- Drill & bits
- Dremel tool
- cutting disc for dremel tool
- small knife (for those stubborn vac hoses)
- Wooden blocks
Note: Clean ALL bolts that are to be reused, a wire wheel works great. Wrap and bolts that hold vacuum or water with Teflon tape.
Step 3. Removal
- First thing is to make a drawing of the vacuum lines, note what goes to where and when there is a delay valve, note the colored side. If you have a service manual it is better to skip this stage and re plumb from book. I did both and found a few lines misconnected which I attribute to the engine rebuild.
- Now remove the air cleaner & fresh air intake, note vac lines on under side of air cleaner. Replace these. Check the doors inside the snout and repair if necessary.
- Next remove the coil and bracket for A/C if equipped.
- Label wires to coil, distributor. A/C and water temp sensor, disconnect and move to the side.
- Drain the Radiator and remove the upper radiator hose and water header line going to the rear of intake manifold.
- Remove ALL vacuum hoses.
- Disconnect fuel line and filter, discard old fuel filter. Disconnect fuel line from fuel pump and cover fuel pump to keep any unwanted items from entering.
- Disconnect the throttle, transmission and cruse control linkage. Note that the transmission linkage can be pushed back out of the way without removing the bolt on back side of the block.
- Now remove the intake bolts, you can get to the 4 front and 4 back bolts with a 9/16" socket and a long ext. The center 4 need a 9/16" open end, I have a long 9/16" combo that really helped, the extra length makes breaking the bolt loose easy.
At this point you are ready to remove the manifold with the old carb still bolted on. Mine was stuck pretty good so I had to use a tire iron to break it loose. From the front, brace the end of the tire iron (or breaker bar if you have one) against the front lip of the manifold and across the A/C bracket. I little pull and you will hear the left side break free. Now get a large screwdriver or pry bar, climb up on top of the radiator/left fender. Grab the carb and pull up, this will expose a small crack between the manifold and head on the passenger side. Slip the pry bar in and pop the manifold up. This should break it free all the way around. Lift it out, carb and all.(note the stock manifold is VERY heavy) You may want help here unless you are a Big guy!
Step 4. The new manifold
- Carefully flip manifold upside down over a pan to drain remaining fuel from carb.
- Use a drill to remove the rivets holding the heat shield from bottom of old manifold.
- Test fit heat shield to bottom of new manifold. I had to use a Dremel tool to remove a small square (app. 1"x.5") from the shield to clear one of the new intake runners. Support manifold upside down with wooden blocks. Use supplied pins and a hammer to install heat shield on new manifold.
- With the old manifold on the bench or floor, remove all existing fittings and EGR valve if equipped. If fittings are hard to break loose, turn manifold on its side so your wrench is pushing downward, this will keep the manifold from trying to move. Discard the old temp sending unit. It helps to spray first with liquid wrench or a similar lubricant. Do this one at a time and move to equivalent position on new manifold, loosely fitting them, do not tighten yet. I took each piece and cleaned them up on a wire wheel, this will clean the treads for easier install and make the look better.
- Now wrap the treads of each fitting with Teflon tape and tighten them. Pay attention to the direction the vacuum fitting is facing, the Teflon will give you a good seal so tighten and back off until vacuum fitting is facing the right direction.
- Remove the water neck, throw away the thermostat.
- Install new temp sending unit, thermostat & gasket. Once again the wire wheel will clean up the old water neck nicely.
- Now back to the engine.
- Remove and discard old metal gasket(Anyone ever seen anyone else use a gasket like this before?) and rubber gaskets from block/heads.
- Wad up paper towel and carefully insert into intake tracts in the heads. Cover valley pan with large rags,
- Use a scraper and remove residue from old gasket sealant from heads and block.
- Spread a thin layer (NOT a bead) of new sealant on heads.
- Insert new metal gasket. This gasket has 4 embossed holes, 1 in each corner, these will face down and pop into existing holes in the heads, holding the gasket in place. It VERY important to get this right, it is not hard but make sure the embossed holes go fully into the heads.
- Spread another thin layer of sealant on the metal gasket, and place new rubber gaskets and front and back ends.
- The new manifold is not heavy, but this is still a good time for some help. Carefully set the manifold straight down onto the heads. Try not to move it around much or you can unseat the gaskets. Now start from the center on hand tread the intake bolts. Once all bolts are treaded, tighten just until they touch the manifold, following the tightening sequence. (This will be in the instructions with the manifold or can be found in the service manual). Now torque to spec again in the correct sequence.
Step 5 Carb and reassemble
- Now you are ready for the new carb. Just place carb gasket/heat shield on manifold, set on the carb and tread the 4 screws. Tighten the bolts with a box-end wrench in a crisscross pattern, not to tight, chock up on the wrench so as not to get to much torque. Better too loose than to tight, it is an aluminum manifold and you don't want to think about stripping the treads. You can always come back later and tighten if you get it to loose.
- Reconnect the wiring harness to the distributor , coil and temp sensor.
- Since the new carb has the fuel input on the side instead of the front, you will need to modify the shape of the old metal fuel line. I cut mine shorter and put a 90deg bend in it. Reconnect the metal fuel line to the pump, install new fuel filter and route 3/8" line to the carb.
- This next part took the longest of everything!
- Use the vacuum diagram to hook up the vacuum, EGR and vapor canister. I would go the book on the bench, check 1 line for where it can from and where it went and then go cut a new line for it and install it. Doing this one line at a time until everything was hooked up. On mine (1982) there was an extra manifold vacuum port on the carb that was not on the new Edelbrock. I had a capped port on the same fitting as the power brake boost line, so I used this in place of the one on the carb. Be aware of which ports are timed(ported) vacuum and which are manifold vacuum. Also there are a few delay devices that are unidirectional, make sure that the colored end faces the right direction
- Reinstall the coil and A/C bracket.
- Now its time to make the throttle linkage adapter. Edelbrock supplies a 1:1 scale drawing of the adapter so I cut it out and taped it to a 1" x 4" piece of aluminum stock. Drill a small hole in the center position of each of the holes marked on the template. Since I had 1/8" stock instead of the 1/4" called for, I used the first as a template for a second. Now drill the correct size holes as specified on the template.
- My throttle bracket blocked one of the new holes for the adapter, so I drill a matching hole in the throttle bracket and cruse control bracket.
- Reinstall the throttle linkage and reconnect the transmission linkage. You will have to loosen the slide screw on the transmission linkage and slide it back. No other modifications are needed to the transmission linkage.
- All right time to reinstall the air cleaner and try her out.
- Mine took several rounds to fill the carb with gas, then started up fine.... At around 2000 Rpm's. I let her warm up and then set the idle screw by ear (No Tach).
- Now I connected a vacuum gauge in line to manifold vacuum and set the idle mixture. Pick one of the two jet screws on the front of the carb and turn it clockwise until it almost dies. Now slowly turn it back out until you get the best vacuum, repeat procedure for other screw. That's it, Now go enjoy your FSJ.
Note: Two days later when it got to 85 deg here in Dallas, I discovered that there is no fast idle for the A/C. I am going to remove the solenoid from the old carb and adapt it, will let you know the results
1982 Jeep Wagoneer LTD