How to: R+R lower intake

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

Good writeup! You might as well replace the thermostat and its gasket while you have the coolant drained. Also have a look into the LIM and see if it's clean and doesn't contain any buildup, before you put it back on.

Also, before putting the valve covers back on, check to see if there's any obvious play between the rocker arms/push rods. Now would be the time to replace them. It's a simple job, but will save you a lot of noise

What's the metal-colored thing you have there at the center-back (in the valley). You don't use the electronically controlled ignition system?

Good write up, I agree with RobertFord on now is a good time to replace the thermostat.

RobertFord said:

Good writeup! You might as well replace the thermostat and its gasket while you have the coolant drained. Also have a look into the LIM and see if it's clean and doesn't contain any buildup, before you put it back on.

Also, before putting the valve covers back on, check to see if there's any obvious play between the rocker arms/push rods. Now would be the time to replace them. It's a simple job, but will save you a lot of noise

What's the metal-colored thing you have there at the center-back (in the valley). You don't use the electronically controlled ignition system?

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Ur right it is a good time to replace it, however i had just done that so i didnt care to disturb it. The metallic thing in the center back of the valley is the phase sensor. It goes where on distributor engines the distributor goes, in this case it only needs to figure out on what stroke the engine is.
If only my imageshack app would cooperate id post more pics.

changed oil a couple times since scoring an 94xlt although ive done most tune ups noticed a lot of gunk on the AIC when replacing AIR charge sensor so its time for the intake cleaning any way i look at it im searching for zen through the range of throttle response and im not getting what spuratically i know exists xanadu couple nice rite ups

the first oil change told a story of many miles i used a havalin senior miles oil with detergents for a short time when i decided to go to straight synthetic the havalin was somewhat dirty after a couple hundred but now the new oil is nice and clear .....tells me detergents work to clean out sys why cant it be that easy for intakes ...:/ automatic oven cleaner mode :/ egr , engine seep ,fart ,gasps what a swaaber im going to look for gaskets and some sanding rolls and mabe some beer

any luck with mass ammounts of laquer thinner or seafoam in the gas ?

smegun said:

changed oil a couple times since scoring an 94xlt although ive done most tune ups noticed a lot of gunk on the AIC when replacing AIR charge sensor so its time for the intake cleaning any way i look at it im searching for zen through the range of throttle response and im not getting what spuratically i know exists xanadu couple nice rite ups

the first oil change told a story of many miles i used a havalin senior miles oil with detergents for a short time when i decided to go to straight synthetic the havalin was somewhat dirty after a couple hundred but now the new oil is nice and clear .....tells me detergents work to clean out sys why cant it be that easy for intakes ...:/ automatic oven cleaner mode :/ egr , engine seep ,fart ,gasps what a swaaber im going to look for gaskets and some sanding rolls and mabe some beer

any luck with mass ammounts of laquer thinner or seafoam in the gas ?

Click to expand...

Lolwut... your post is very hard to read. I think your question is how to clean the intake manifolds? If you think about it the only way would be to remove them and clean them out manually. Adding anything to the gas would only be introduced at the fuel injectors so it'd only affect the lower intake, and the spots where the injectors spray are already well cleaned by the gasoline itself. Once removed, degreaser and a pressure washer works somewhat. Really there shouldn't be enough gunk in the intakes to cause any harm, but if there is a lot you should install a PCV catch can because blowby may be depositing a lot of oil vapor into your intake. With a catch can set up you should be able to clean the intakes once and never have to again.

My Fel Pro gasket kit (Gasket Kit - FEL-PRO MS98005T ) has a 2 part LIM gasket, instead of the 1 piece unit I took out. There is no gasket for the valley, is that OK?
It's a '93 4.0 L
Thank you for any input.
OK solved my own problem, you need the valley covered to keep the oil from spraying up onto the LIM.
I am posting pics here http://www.explorerforum.com/forums/showthread.php?t=399036 of our re and re of the gasket, removing AC and general overhaul along the way. Thanks to OneofMany and all the other posters for this thread, I hope the pics help someone along the way.

I think either the one piece or 2 piece do fine. All v8s of that generation or older have 2 piece and you just use silicon to seal between the block and the Lower intake.
Thanks for the thanks, i worked hard on this and am glad i wrote it up because i would have to relearn it now- sucks to have bad memory.