OneofMany
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- Joined
- December 21, 2012
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- City, State
- Georgia Mountains- Talullah Falls
- Year, Model & Trim Level
- 94 expl 4x4
This is a writeup on replacing the intake gaskets, injector O-rings, fuel pressure regulator, valve cover gaskets and plugs on a 91-94 4.0 v6. Later models would not be much different. Im not going into great detail but covering the basics so you can tackle this yourself. I recommend using the TSB http://rockledge.home.comcast.net/~rockledge/RangerPictureGallery/Early40LIntakeGasketTSB.pdf
The reason why Im replacing the spark plugs at the same time is ease of access to them with the valve covers removed. Total cost of this job about $200 using FelPro gaskets. Its not a fast job due to the gasket surface cleaning.
Drain Coolant, disconnect battery negative and ensure it cannot touch the battery accidentally;
remove upper Radiator hose from thermostat housing, throttle cable, all vacuum hoses from vacuum tree at back of upper intake, remove intake hose from MAF and throttle body. remove EGR valve etc.
Remove spark plug wires from coil and harness on intake, be sure to note their positions, remove coil pack. remove wiring connectors except the one that goes down beside the water pump.
remove upper intake, remove upper heater hose and move remaining wiring move wiring harness out of the way to the left leaving only the 1 wire the runs down beside the water pump.
Remove sources of ignition, put on safety glasses.
Drain pressure off the fuel rail by means of the schraeder valve on the left, loosen and move aside the fuel lines to the right(wire braided) and the junk off the fuel pressure regulator.consider replacing it. remove studs holding the fuel rail down using a torx E7. turn the injectors to break the o-rings loose and pop the fuel rail off the injectors one at a time take a break to let vapors dissipate since you just spilled half a cup of fuel. leave injectors in intake for now.
Remove valve covers.
Remove lower intake, it should pop off easily if not bump it a few times with a sledge hammer- erm- no use a mallet.
Uploaded with ImageShack.usNow behold the mess and open a bottle of beer but use the good kind, not the mass produced light beer ****. Now lay rags in the valley to cover and catch junk you will be scraping out of the ports and sealing surfaces next. Use a scraper for the gasket remnants, then wipe off oil and dirt with a solvent like denatured alcohol. If you have access to compressed air and an angle grinder with polishing disc and a parts washer now it would come in handy. Otherwise scrape without burring the aluminum. check valve covers for distortion at gasket surfaces.
Reassembly:
Install spark plugs. use dieletric grease on rubber boots and connectors.
Use RTV silicone as recommended by gasket manufacturer on the valleys, do not let silicone harden before dropping the intake on, then go to the valve cover gaskets right away because you need to put a little RTV at the junction beween intake and cyl head where the valve cover seals. Run all bolts down by hand then torque according to spec.
Now reinstall lower intake to fuel rail gasket and fuel rail, if you replaced the injector seals like i did you would have inserted them into the intake and now placing the fuel rail ontop of them and guiding them into their places and gently pressing the fuel rail down ontop of them, reinstall bolts and torque THEN drop upper fuel rail to upper intake gasket on.
Now reinstall wiring harness and reconnect.
Reinstall coolant hoses
Reinstall upper intake and torque, reinstall plug wires, coil, connectors, repair all the vacuum lines you broke. reinstall throttle cable (lube it) and everything else. Do change oil soon after this job due to all the junk you loosened up and dropped into the engine.
remember to add coolant. remember everything i didnt cover. dont blame me
The reason why Im replacing the spark plugs at the same time is ease of access to them with the valve covers removed. Total cost of this job about $200 using FelPro gaskets. Its not a fast job due to the gasket surface cleaning.
Drain Coolant, disconnect battery negative and ensure it cannot touch the battery accidentally;
remove upper Radiator hose from thermostat housing, throttle cable, all vacuum hoses from vacuum tree at back of upper intake, remove intake hose from MAF and throttle body. remove EGR valve etc.
Remove spark plug wires from coil and harness on intake, be sure to note their positions, remove coil pack. remove wiring connectors except the one that goes down beside the water pump.
remove upper intake, remove upper heater hose and move remaining wiring move wiring harness out of the way to the left leaving only the 1 wire the runs down beside the water pump.
Remove sources of ignition, put on safety glasses.
Drain pressure off the fuel rail by means of the schraeder valve on the left, loosen and move aside the fuel lines to the right(wire braided) and the junk off the fuel pressure regulator.consider replacing it. remove studs holding the fuel rail down using a torx E7. turn the injectors to break the o-rings loose and pop the fuel rail off the injectors one at a time take a break to let vapors dissipate since you just spilled half a cup of fuel. leave injectors in intake for now.
Remove valve covers.
Remove lower intake, it should pop off easily if not bump it a few times with a sledge hammer- erm- no use a mallet.
Uploaded with ImageShack.usNow behold the mess and open a bottle of beer but use the good kind, not the mass produced light beer ****. Now lay rags in the valley to cover and catch junk you will be scraping out of the ports and sealing surfaces next. Use a scraper for the gasket remnants, then wipe off oil and dirt with a solvent like denatured alcohol. If you have access to compressed air and an angle grinder with polishing disc and a parts washer now it would come in handy. Otherwise scrape without burring the aluminum. check valve covers for distortion at gasket surfaces.
Reassembly:
Install spark plugs. use dieletric grease on rubber boots and connectors.
Use RTV silicone as recommended by gasket manufacturer on the valleys, do not let silicone harden before dropping the intake on, then go to the valve cover gaskets right away because you need to put a little RTV at the junction beween intake and cyl head where the valve cover seals. Run all bolts down by hand then torque according to spec.
Now reinstall lower intake to fuel rail gasket and fuel rail, if you replaced the injector seals like i did you would have inserted them into the intake and now placing the fuel rail ontop of them and guiding them into their places and gently pressing the fuel rail down ontop of them, reinstall bolts and torque THEN drop upper fuel rail to upper intake gasket on.
Now reinstall wiring harness and reconnect.
Reinstall coolant hoses
Reinstall upper intake and torque, reinstall plug wires, coil, connectors, repair all the vacuum lines you broke. reinstall throttle cable (lube it) and everything else. Do change oil soon after this job due to all the junk you loosened up and dropped into the engine.
remember to add coolant. remember everything i didnt cover. dont blame me