Picked up the license plates for my 80 on Tuesday afternoon, so I decided that Tuesday morning was the perfect time to do a valve tune! It was an amazingly simple process, and I definitely think I'm getting better throttle response and power. I wasn't totally happy with the first tune, one of the valves was still loud after a test drive, but the second time around only took about 25 minutes from start to finish. Note: this is for the 3FE engine!
What you'll need:
-Feeler gauges
-10mm end wrench
-Socket set (10, 12, 14mm. 4-6in extender also helps.)-
-Breaker bar
-Straight screwdriver
-Valve cover gasket (mine looked fine but always a good idea to have a spare in case yours is old and rotted)
-RTV
-I used a paint marker to keep track of the hoses I disconnected
-flashlight
-gloves that will keep you from getting burned while you pull the valve cover off
The 3FE valve clearances are posted on the hood of the vehicle, and in the FSM. Always good to double-verify!
You only need two of the feeler gauges: .014" and .008" for the exhaust and intake, respectively. I recommend getting a set that has a bend towards the bottom rather than the totally flat ones that I have, just because it's easier to get the gauge in there without dropping it!
Make sure your engine is up to operating temperature before doing this. I took my truck for a short drive around the neighborhood, and made sure I knew what wrenches I was going to need and had everything ready to go before I shut off the ignition to start work.
I marked all the hoses with dots so I knew which ones went where when I was done. They're intuitive, but I also know that I would be the one to have a brain fart and swap some by accident.
Killed the engine, pulled the big air intake hose off, loosened the throttle cable bracket, pulled off the hoses attached to the valve cover, and pulled the vacuum lines free that attach to a bracket on the back of the air intake hose, You want as much room as possible towards the firewall so that you can get the valve cover clear of that back bolt stud. Removed the four bolts holding the VC on, and the small gaskets that seal between the cover and the bolts. Removed the head cover, put it somewhere nice and safe (the ground). Then, turn the engine until you're at TDC. I used the power steering pump pulley (17mm) and a breaker bar, but any spot that moves the crank should be good. The window took me a sec to find, it's tucked back on the passenger side of the flywheel (red arrow). Definitely need a flashlight to see back in there. Rotating the crank and watching the flywheel is much easier with two people so you can maintain line of sight.
My flywheel had a bunch of white paint dots on it, but the bb that marks 7 degrees BTDC and the mark of TDC are both imprinted on the flywheel. The bb is one larger mark, and the TDC mark is two smaller marks, radially aligned. If I ever feel super motivated, I'll get some colored paint and mark them better but it's a tight spot to reach and once you know what they look like, they're easy to spot. At TDC, check the rockers on cylinder 1, they should be loose. The rockers on cylinder 6 should be tight. If 6's are loose and 1's are tight, you're at BDC and need to turn the flywheel another full revolution. Again, I found it was easier to have one person turn the engine while another person acts as spotter.
The FSM has a really good writeup and diagram for the actual tuning. I recommend using an end wrench and a slotted screwdriver instead of a socket to do the adjustment so you can control the adjustment at all times.
For example, on the intake of cylinder 5 as marked below, end wrench on the blue arrow, straight screwdriver in the slot by the red arrow.
Once at TDC, you'll check the clearances on the following valves: 1ex, 1in, 2in, 3ex, 4in, 5ex. (both valves on cylinder 1, then the front valve on cylinders 2-5). Slide the feeler gauge between the valve stem and the rocker arm. Proper valve clearance should have a slight drag when sliding the gauge between the two. If the clearance is off, loosen the lock nut, adjust the screw, and hold it in place while tightening the lock nut back down with the end wrench.
Once those valves are adjusted, rotate the flywheel 360 deg to BDC, check the other valves: 2ex, 3in, 4ex, 5in, 6in, 6ex (back valves on cylinders 2-5, both valves on cyl 6).
At this point, your valve tune is done, and it's a matter of putting everything back together. Make sure all your hoses went back to the right spots! A little RTV helps keep the gasket in place while you're shoving things around, so highly recommend.
I took Pam for a test drive and still heard a little clatter so I did a second tune after the test drive. So much faster than the first time! I just checked all the valves, even though I was pretty sure it was the exhaust valve on 2, and verified that everything was still hunky dory. Put everything back together, and she sounded good to go!
Still need to adjust the kickdown cable, but after adding 2 more quarts of trans fluid (it barely showed up in the "cool" range even after the dipstick was hot and the engine was running) and getting that adjusted, I'm hoping it will shift more smoothly. 99% of the time, it's totally fine, but sometimes I'll get a false neutral on hard upshifts. Also sometimes get a good clunk at lower speed shifts.
CEL came on during her maiden voyage (do you really own a landy until you've camped in it?), so the O2 sensors are now next on the list.