These pages are devoted to the 1991 3000GT VR4
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The 60k Tune
 

OK, the long awaited 60k tune page is here. You sure you are up for this???

The 60k tune is not for the every day guy. You do need to have some mechanical ability aside from having
the correct tools and mechanical skills to go along with it. I assume no liability from publishing this
web page if your 60k tune fails.
Even Dealers mechanics have had many a 60k tune failures as per info from the members of 3SI. Of
course they will blame it on something else because they do not want to pay for an engine rebuild
out of their own pockets. I can't blame them for that, but do wonder why they accepted the work
in the first place. Then again dealers do not have a choice. They have to do it or lose their contract
with the manufacturer. Well, that said, here is the process. Proceed at your own risk.

First off you need to order the following parts

Timing Belt - Proper Name - Belt Valve - MD193874
Water Pump Assembly --------------------------- MD972005
Adjuster, Timing Belt Tensioner ------------- MD319040
Pulley Timing Belt Tensioner ----------------- MD140071
Pulley, Timing Belt Idler ------------------------- MD319022

While you are at it order a timing belt Tensioner Pulley tool or borrow one. It makes it a lot easier to
accurately adjust the belt. The 60k tune at dealers calls for new plugs and wires also, though that is
     not covered in this. To me they do not have to be done together at the same time and are unrelated
as far as being advantageous because of parts that need to be removed. If your car is not misfiring
odds are plugs and wires do not need changing.

The following process must be completed in order of number to facilitate a smooth job.
Goes without saying, but jack the car up and put the front end on Jack Stands.

                                             1. Drain Radiator and remove hoses both top and bottom.
                                             2. Remove the Radiator Brackets on top.
                                             3. Remove the Intercooler to Y Pipe metal pipes and hoses that run in front of the Radiator.
                                             4. Unplug the Radiator Fans on the right and left side and lift out the Radiator, fans and all.
                                             5. Remove drivers front wheel and wheel well skirting both toward the engine and the intercooler.
                                             6. Loosen the bolt in the center of the serpentine adjusting pulley. (Lower Idler pulley)

Note: Looking at the below photo from my 91 VR4 you can see the serpentine adjuster I am referring
to just to the right of center bottom and the adjusting bolt you need to loosen. Refer to my page on
serpentine replacement if you need to.  You can also see the A/C pulley to the left the upper idler
mounting hole a little above center looking in through the drivers wheel well. To the right you can
see the side of the crank pulley.

                                             7. Turn the adjusting screw above the adjuster pulley counterclockwise to loosen the serpentine.
                                             8. Remove the serpentine belt from the alternator and A/C unit and remove from car.
                                             9. Unbolt the Alternator Bracket and carefully let it drop down to rest. There is two bolts
                                                 up top and two on the side. You do not need to unhook the electrical, nor do you have to
                                                 remove the alternator from the bracket.

                                             10. Next remove the crank pulley center bolt.
                                                  Disclaimer: This might sound unorthodox to you , but trust me I have done it several times.
                                                   It is very unlikely you have an impact wrench strong enough to remove the bolt, so this is
                                                   the best and proven way. I can not guarantee that all will go well and one might "feel" there
                                                   could be problems doing this, but I have never had any problems doing it myself.
                                                   Take a common 1/2 drive ratchet with a socket and place it on the bolt head and rest the
                                                   handle on the cross frame or solid place and crank the engine with about a 1 second hit.
                                                   Looking at the engine from the drivers side wheel well the engine turns clockwise when
                                                   cranked. The bolt comes out counterclockwise as all bolts do. You will hear a pop and
                                                   the bolt will be loose. Just pay attention to orientation and provide for minimum travel of
                                                   the ratchet handle. Remove the bolt and then pull out on the pulley to remove it.
                                             11. Unbolt the Accelerator / Cruise Control cable box. and swing it up over the engine and out
                                                   of the way and tie it off with an old shoestring to the underside of the hood somewhere.
                                            12. Remove the upper two timing belt covers.
                                             13. You can now remove the drivers side motor mount by removing the three nuts on top.
                                                  We need to support the engine from below which can easily be done with a floor jack and a piece
                                                  of wood to protect the oil pan. Jack it up just enough to relieve tension on the motor mount bracket
                                                  which will be only about an inch. Also remove the one bolt going through the motor mount.

                                             14. Remove the motor mount brackets bolts . There are bolts on the drivers side as well as
                                                   two bolts from the A/C compressor bracket. Local them all and remove them and pull it
                                                   out of the engine bay.
                                             15. Remove the bolts from the side timing belt cover and remove it. Make sure to disconnect the
                                                   crank and cam angle sensor plugs. Don't worry which is which because the plugs are mated
                                                   and you can't confuse them during reassembly. Slide the crank or cam angle sensor plug off
                                                   the bracket so the wires can be separated. The crank angle sensor plug and wire can just
                                                   hang down below and the cam angle sensor plug and wire can be brought up top out of the
                                                   way. In the photo above you can see the wire in the upper right corner.

                                                   You should now have the timing belt completely exposed. The tensioner and idlers should be

                                             16. At this point we want to make sure all our marks line up on both sets of cams plus the crank.
                                                   In the following photo you can see the cam sprocket marks and the mating marks on the valve
                                                   cover as I have painted them pink so you can identify them.

                                             Once all marks are lined up, you can do as I did and make yourself some cam holders or fight
                                             with it like Mechanics or others have done. I prefer my way thank you. I cut a rectangular piece
                                             of wood (OAK) and cut it on a angle in half to make two V type wedges. I then placed them wide
                                             side to wide side, clamped them in my drill press and drilled a 1/4" hole through them both. I then
                                             cut a piece of 1/4" rod stock and placed it in the holes so the narrow ends faced each other with
                                             nuts on either end. I then used these as wedges between the sprockets to hold them into place.
                                             I am going to apply for a Patent on this tool so don't consider doing the same because I already
                                             have record of it being posted with dated photos in here and that would be design theft. I am
                                             supplying this info to you free so it can help you. Not to give away ideas. Here is a photo. A little
                                             premature because in this photo everything is just about done and no we are not done yet,
                                             but you can see the wedges. Reason for the wedges is because the cam sprockets are connected
                                             to the cams which rest on the lash adjusters which are spring loaded and the cam sprockets will
                                             spring to a resting place if not retained in place. If the wedges are not used, the cam sprockets will
                                             all have to be realigned (Timed) while trying to install the new belt which is not an easy task at best.
                                             Others have suggested using large sprung metal paper clips. Only trouble with that is you still
                                             have to align the sprockets once you remove the old belt. My way, nothing moves. A really hard
                                             part made simple by yours truly.

                                             17. It's now time to remove the old belt. Loosen the bolt in the middle of the adjuster pulley and
                                                   tension on the belt will relax.

                                             18. Pull the belt off taking mental note of the path the belt takes around the various pulleys and
                                                   sprockets. If you forget anything the whole patch can be made out in the above photo.

                                             19. I won't go into great detail on removing the Water Pump as it is fairly simple. You will get a
                                                   little additional coolant from the block leaking down, so be prepared with a drain pan. I have
                                                   found that a huge plastic concrete mixing vat that is about two foot by three foot to be an ideal
                                                   drain pan for both undercarriage clean up and washing and for doing jobs like this. It's big, so
                                                   no worries about what is draining is missing your little drain pan. They are readily available at
                                                   your local Home Depot.

                                              20. Below is a photo of what it looks like once you have removed the 5 bolts for the pump and
                                                   popped the pump out of there. In this case we can see that #1 It was leaking. and #2, there was
                                                   an insufficient amount of anti- freeze mix which is evident by the rusty water draining down.
                                                   While this does not cause huge problems internally for the engine, the rust is actually metal
                                                   floating around in the water  / Anti-Freeze mix and we all know metal holds heat.
                                                   Also anti - freeze is not only to prevent the cooling water to not freeze, it also raises it's
                                                   boiling point which further protects the engine from boil over or steam collection. Anti -
                                                   freeze should be a 50/50 mix. What I did once is save the empty container. As soon as I
                                                   bought a new gallon I poured half of it into the old container and topped off both with water
                                                   which gave me two gallons of 50 / 50 mix. No guesswork from using full strength with a hose.
                                                   I also use the mix whenever the reservoir gets low for some reason and never just plain water.
                                                   Taking care of the system you really should not have to top it off hardly ever.

                                             21. Back to the pump replacement, now is the time to clean that whole area up, and get all old
                                                   gasket material off if the old gasket was paper. If it was metal, just make sure the surface is
                                                   clean and generally clean up the whole area and use rust converter and paint. Below I have
                                                   cleaned it up considerably.
 

                                              22. Then rust converted and painted

                                                23. Shown below is the back side of the new Water Pump. Apply Permatex Blue Gasket maker
                                                      to the back side where the gasket will touch to hold it in place. In this photo also you can
                                                      note the locations of the 5 bolt holes. I also apply gasket maker to the other side just for a
                                                      little extra guarantee. Not necessary, just a habit of mine to place a thin coat in addition
                                                      to the gasket itself. Of course it is only needed in the two outside areas where the water
                                                      seal exists as you can see better if you enlarge the photo.
 

                                                         24. Ok, next step is to install the tensioner. I assume you have already cleaned up and
                                                                painted your tensioner arm too, haven't you........ Next photo shows the tensioner
                                                                installed. Two bolts cleaned and painted . Simple task. Note marked location of the
                                                                crank timing mark that I have colored pink. There is a corresponding dot on the
                                                                sprocket itself. I assume you have read this entire instruction page before starting,
                                                                because this is really past the point where you would know it's location in actual
                                                                work completed.

                                                         25. In the photo below you will see both the Idler Bearing and the Tensioner Bearing
                                                               installed. Idler bearing tightened to specs and tensioner bearing just snug as we
                                                               still have to adjust the tension on the belt. You will also notice that even though
                                                               the new tensioner comes all shiny I have painted it also after install because the
                                                               old one came out quite rusty, so it is not plated or coated with anything.
                                                               When I say specs, if you wish to look up the torque specs, feel free. I have been
                                                               working on stuff concerning bolts for so long now I used my arm as a torque
                                                               wrench. I mean I own one, but about the only time I would use it would be for
                                                               bearing blocks or something really critical. It has worked for me. Some people
                                                               are real fanatics on torque specs. I am just not one of them.

                                                         26. Ok, we are now at the point of installing the new belt. Shown below is one photo which
                                                               is where we wish to start. The crank sprocket. The belt should install somewhat loosely all
                                                               the way around.  Moving from the crank sprocket over the rear idler bearing towards the
                                                               rear cam sprockets make sure the belt is as taught as you can make it. If it is almost
                                                               dropping into the next set of teeth, pull hard and make it go there, possibly tapping lightly
                                                               with a rubber hammer. If you don't have one, even more lightly with a regular hammer.
                                                               Once real tight, move over the rear cam sprockets down under the Water Pump pulley
                                                               and back up to the front cam sprockets. Again if it is almost going into the next set of teeth,
                                                               make it go there.
                                                               Before doing this you may wish to use small clamps to hold the belt in the rear sprocket
                                                               teeth or you may wind up starting over if it comes out of the teeth in the rear cam sprockets.
                                                               Once you are in tight from the crank sprocket all the way to the front sprockets your "slack"
                                                               should be at the tensioner. This is where the tensioner tool comes in handy to turn the
                                                               tensioner bearing so that the tensioner is exherting force on the bearing arm and compressed
                                                               to the point of the stay pin loosening up so you can remove it. DO NOT remove it yet.
                                                               Apply force to the tensioner tool or if you are innovative enough to use a large screw driver
                                                               to apply the same force on the arm, you can also do it that way. Be firm in your convictions
                                                               that you know what you are doing if you do not use the tool.
                                                               This is the area a lot of Dealers mess up at. They do not get the tension tight enough. I suggest
                                                               making the tension tight enough so that the pin is harder to remove on the tight side, not the
                                                               loose side of tension. Then and only then tighten the center bolt of the tensioner pulley and then
                                                               and only then recheck the pin to make sure it is still on the tight side of tension.

                                                          This concludes the timing belt install. All that remains is putting everything back together again.
                                                          Start with the motor mount inner bracket and then the shields and then redo the Power steering
                                                          and Alternator belts. I won't go into great detail on that because it is just a reversal process.
                                                          Take notes if you must on the order you went in and just reverse the projects one by one.