HOW TO: REVIVE AN F-SERIES ENGINE THAT HAS BEEN SITTING DORMANT
This is an actual customer’s 1974 FJ40 Land Cruiser that came into the shop for an inspection diagnoses and potential revitalization of the F-Series engine. This 40-Series was not in running condition upon delivery and had been sitting for some time. So where did we start? With the engine of course! It is the heart of vehicle and without the engine, it’s just a static bolt-together metal model sitting in your garage for display and bragging rights. Maybe you’re OK with a #StaticDisplayModel but here at Red Line Land Cruisers we are TOYOTA DRIVING ENTHUSIAST! We want this F-Series Toyota engine to run!
We are located in Colorado Springs, Colorado sitting at an elevation of 6,035 feet (1,839 m). That’s over 1 mile (1.6 km) above sea level, though some areas are significantly higher and lower. Red Line Land Cruisers (shop) is roughly at 6,200 feet.
It’s February 4th, 2022 and temperatures for the day are: HIGH: 26 °F / LOW: 15 °F. When we pull the rig into the shop, it’s as cold as an ice cube so we put the heat lamp on it while we are finishing up other tasks.
PRIMING THE F-SERIES OIL SYSTEM
The first thing we will do is prime the engine oiling system. Why? Let’s put it two you in two different analogies; [One] You’re sleeping hard after a long night hanging out with friends and your mom storms in the door banging pots and pans together like she’s in a marching band at the Macy’s Thanksgiving Day Parade. [Two] You’re one day in of military basic training, your Fort Benning Ranger School Sargent kicks in the door at 3:53AM, whistles blowing, fire suppression sprinkler system raining down and emergency flashing beacon blindly flashing at 98-bpm. Your heart went from a cool rested 48-bpm to 190-bpm in TWO SECONDS! These scenarios may be physically healthy for those who are under the age of 30, but this 1974 Toyota Land Cruiser with it’s F-Series engine is some 48 years old here in 2022! Do you think it’s healthy to wake your mom or dad up – all alarms blaring!? You might take a few years off their life and same goes when reviving these old engines. It’s all about preservation without or prolonging a complete engine rebuild. (Third bonus analogy is probably the best as it is closer to what is actually happening in your engine – wakey wakey!)
REMOVE THE AIR CLEANER
We remove the air cleaner cover to both inspect the air filter and to get to the carburator. We remove vacuum lines as we will be removing the valve cover as well.
But don’t forget where you put them! Yes, we will be putting the proper wingnut back in it’s place to make the Toyota Land Cruiser gods rest easier.
REMOVE THE VALVE COVER
We remove the valve cover as we will be visually inspecting to see if we are getting oil to the top of the engine’s valve train during our priming session. You most likely will be adding a new valve cover gasket (11253-60010 Valve Push Rod Cover Engine, Valve Cover Gasket for 1969-1987 Toyota Land Cruiser), so maybe order that in advance and or wait – your call.
REMOVE THE DISTRIBUTOR – AKA: DIZZY
Typically the camshaft drives the dizzy-gear to drive the oil pump, thus it is essential, rather critical that you “stab your dizzy” correctly to assure that you are spinning the oil pump! #OilisLife
With the dizzy removed, we notice what looks like a “trash-talking” dizzy! It looks as though it is has not been sealing completely. Again, it’s critical to have your dizzy stabbed correctly!
With that, we inspect the oil and it looks freshly changed, but looks can be deceiving as to the type of care the engine received previously. It’s the ol’ used car salesman trick of “lets slap some fresh oil in it so it looks fresh!” “Yheap! We change it every 3k!” But you have to look beyond the oil, look closely… Closer! Look at the “crust of past days” within the crevasses of the cross-hatching and the L – F letters. It also looks as though someone over-filled it too.
SIDE NOTE: BEST WAY TO CATCH YOUR RIG ON FIRE • These in-line fuel filter “windows” are made from cheap pot metal with screw-in fittings and always seem to fail! We simply DO NOT USE THEM!
REMOVE THE OIL PRESSURE SENDER • Located on the driver side of the block.
INSTALL OIL PRESSURE GAUGE
Note: The oil pressure gauge you are about to use needs to fit the factory Toyota ⅛ BSPT as in British Standard Pipe Thread. Do you really want to be tapping your block after you remove your buddies oil pressure gauge? Be patient! DO IT RIGHT – the first time – WITH THE RIGHT SIZE THREAD!
OIL PUMP PRESSURE
We have our home-made “dizzy-spinner” as the “keyed-tip” of the dizzy is what spins the oil pump. You will want to find yourself another old / bad dizzy and make into a test unit to spin your oil pump. Need help identifying a dizzy? Check out Name That Dizzy on IH8MUD – While spinning the Dizzy / Oil Pump, we like to see 40 – 60-psi on warmer days. A cold engine (during cold weather) may show a little more compression.
OF COURSE THE BATTERY IS DEAD! • OK, it’s insufficient at a whopping 4.9-volts of juice!
While spinning the dizzy/oil pump, we will also power the starter intermittently with a MAC TOOLS SS55HDA
12V Heavy-Duty Remote Starter Switch to push oil up to the top of the engines valve train.
We removed the spark plugs to get ready for the compression test. We note the two extremes: No.1 & No.4.
SET THE CARBURETOR THROTTLE BLADE
The carburetor throttle blade need to be all the way open. We take an extendable hood-prop and set it between the seat and the throttle. You can use a brick, 2X4, anything to hold the throttle all the way open. Dealers choice. #SkinnyPedalDown
COMPRESSION TEST • With our Oil System primed and visual verification that oil is getting to the top of the engine, we will now start our compression test as we continue our quest of reviving the F-Series Toyota engine. With the compression test, it will give us a rough idea of the condition of the rings, valves and maybe the head gasket. All these are sliding scale of variables.
Your Oil Pressure Gauge may have various thread adapter fittings, but does it have the proper one to fit your Made-In-Japan F-Series engine block. Notice how we didn’t say “metric thread?” because it is not metric, it is actually British Standard! Don’t smash the incorrect fitting in just because you want to proceed tonight! Remember, you have to screw the Oil Sender back in there!
Compression test results:
We’ve been known to bend a tube or two… Tube Service Co supplies us with the straight ones.
These Compression Test numbers are decent for both our elevation (6,200-ft) and the age of the vehicle. Engines with 300,000-miles will typically see 90 psi, but for us, the 90 psi on cylinder No.4 is concerning.
If all these numbers where below 90 psi, we would highly start considering a rebuild as the engine would be struggling for air!
LEAK DOWN TEST STARTS DOWN THERE
We will do a Leak Down Test before we move to “curing” the No.4 cylinder. Leak Down Tests starts with moving each piston to top dead center (TDC) we will test each cylinder at the TDC position, thus we have to “lock” the flywheel each time we move the piston to top dead center. BUT, before all that can happen, we have to remove the flywheel inspection plate. Removing the inspection plate is rather tedious as the “PHAT” exhaust is fashionably too “phat” for an F-Engine! It’s too fat to fit our tools around, and too fat to get the darn inspection plate off! Thus, we move to the other side…
REMOVE CLUTCH INSPECTION COVER • For this particular 40-Series Land Cruiser, in order to remove the clutch inspection cover we have to remove the drive shaft as the exhaust is rather large to match the header. and preventing us from removing the inspection cover. To remove the drive shaft, some effort aka “elbow grease” has to be applied with use of an electric powered bionic arm aka the Snap-On impact gun. It’s the little things like this that make simple task… longer simple task. Now, all the crust that was on the drive shaft is now on the floor. Yes, we are a 4X4 shop, we get it, rigs are dirty… The joys of working on old crusty rigs! This, along with every other rig has us dreaming of a massive underwash pressure wash system as our hot-water gas-powered pressure washer recently let out it’s last spurt!
Now we can get on with getting our psi on!
PSI OR DIE
Leak Down Cylinder Test helps expose cylinder leakage paths while testing pistons, rings, seated valve sealing, and the head gasket. The Leak Down test will not show valve timing and movement problems, or piston movement related sealing problems. With the piston at TDC, pressure is fed into a cylinder via the spark plug hole and the flow, which represents any leakage from the cylinder, is measured. Leak Down tests tend to rotate the engine and will require some method of holding the crankshaft in the TDC position for each tested cylinder, hence our wood block wedge. Typically we could leave the manual transmission in a high gear with the parking brake locked, but the brakes are not working. Yes, we could wheel-chock it, but we used the flywheel to dial in the timing so, that is that!
With our Leak Down Test underway, cylinder No.1 held good at 100-psi. With cylinder No.4 being the concerning one, we jumped over No. 2 and No.3 as our curiosity can’t wait any more! With TDC set, flywheel locked, we applied pressure to cylinder No.4 with the Matco CLT2APB Cylinder Leakage Tester. With only 50-psi we already hear air escaping the engine. We feel the air leaking out of the cylinder head at the oil return port hole. Side notes; If you see air bubbles or hear air leaking from the radiator filler, this could be the tell-tale signs of a leaking head gasket, cracked rings or a cracked head.
You could also hear air leaking from the oil dipstick tube. So this is where Compression Test only gives you a brief story and the Leak Down Test gets you a little further down the revival rabbit hole. This is where we are 50/50 on-the-line as to which way this engine may go. We would much rather the engine come alive and run a few more years vs a complete engine rebuild, but we are not the ones in total control of this as the previous owners service & maintenance that is unknown along with the “Toyota Gods” bad / good mojo based on previous owners service & maintenance. So here we are, our next shot at a somewhat easy revival, fingers cross, shoe laces laced and asking for Mr. Kiichiro Toyoda’s blessing!
We also use our INNOVA Inspection Camera to take a peak at the cylinder walls, piston scoring and a bit of rust.
We give cylinder No.4 our special “black magic sauce” treatment for an hour or so as we wire wheel clean the old crusty Champion spark plugs. We are confident that this brand of spark plugs are 98% of the problem! 😂😂😂 We wire these plugs clean vs slapping new ones in to keep any cost down possible. We are NGK folks here even though Denso plugs may be more “Toyotacentric”.
We notice this resistor in-line between the coil and distributor which is a bit self-defeating the old model Pertronix that is in the distributor. This limits the hot spark we are looking for and would expect with the Pertronix! Bypass resistance! We install the dizzy and check the fuel source. We are ready to attempt the actual starting of the engine!
WE HAVE LIFTOFF!
We use a little starter fluid and bring this 1974 F Series Toyota engine to life!
YES! WE HAVE A RUNNING ENGINE! ROUGH – BUT RUNNING under it’s own power!
1] First audible notice is an exhaust leak/s on the header side.
2] The carb is starting to leak at various gasket outlets centers and the throttle linkage is popping off making for a not so easy task of adjusting.
It’s Friday closing time so we prime cylinder No.4 with our “secret sauce” and will we will reconvene the 1F Revival on Monday. One or none of these things may have been used during this revival. If you guessed the faded red “Made In China” cart, then you are correct!
It does a decent job of holding stuff.
ROLL THE PISTONS
Monday morning we typically clean shop and get ready for the week, but we are eager to get back to the ‘74 FJ40 with the engine that has not seen combustion in years! It’s like going to Vegas and placing your bet on the table at 9AM in the morning and our hands are eager to roll the dice! It can be a tricky game indeed, especially when one is not familiar with the dice rolling probabilities and the numerical odds. However, the knowledge of probabilities is of crucial importance as one cannot expect “LUCK” to be on their side, if one does not understand which combinations of ill suited maintenance have prevented combustion.
In “The Game Of Engine” chances of combustion after a dormant stage relies on several combinations to wake an engine. We all know the saying, “if we have air, fuel and spark, we should have combustion.” But when we are asking for a sequence of combustions in a 1-5-3-6-2-4 firing order, with power impulses every 720 degrees/6 i.e. 120 degrees of crankshaft rotation, there is NO LUCK involved! It’s all mathematical equations and systems of equations working together!
Your engine is “Vegas” and you want those cylinders to fire every time, yet you think that only adding fuel is all you have to do. Vegas was built on “the house” winning and winning was built on a combination systems in place, constantly monitored and maintained! Toyota engineers in their little white lab coats spent countless hours of research and development on just maintenance and the creation of the maintenance schedule itself in order to keep the F-Series “house” running! There is no such thing as LUCK! It’s a “random” combination of mathematical equations.
L.U.C.K. = Learning Under Correct Knowledge – We Play To Win!
Throwing parts in the deep end of the swimming pool will take a lot of dead presidents to build an island of success. We take a more methodical approach to these 2F/F revivals in attempts to both save the customer as much money as possible and to also truly find out what life is left in the old engine. “Life after engine” is an expensive endeavor as parts are expensive, time to get said parts is ever-pressing, but too, the labor and time to rebuild these ol’ 2F/F engines is more than just slapping them together. We will talk more about engine rebuilds in a later post, but to keep the engine god’s on our side today, we will mention no more about engine rebuilds for this article and the sake of this engine! Hehehe So yea, no such thing as LUCK, but now we are talking about the “engine gods!”
PRAY FOR CONTINUOUS COMBUSTION!
It’s Monday, We have four hands on deck, the engine has been brought back to life again, we are fine tuning the timing, the screw on the dizzy baseplate was screwed all the way in and is getting dialed into a suitable position, laser gun is getting pointed at the radiator hoses and manifold at each exhaust port.
One hand is keeping the hand-throttle on the carb modulating as the engine is stuttering exhaust notes while the other hand is dialing in the carb’s fast-idle and idle screws.
We want to get some heat into the engine and see if we can keep it living on it own.
It dies of course.
We get the Land Cruisers F-Series engine started again and this time we put a hand over the carburetor mouth to create more vacuum in an attempt to help pull through any crud or crust within the jets of the carb. We start it again to continue with the heating process. We can hear cylinder No.4 popping at the exhaust note, but we continue in attempt to get the oil to operating temperature and hope that No.4’s rings will loosen up. Once we get it to temp, we shut it down. The engine was popping and vacuum leaks are all over, but we have the “feeling” this engine will get a little extension on life. But this by no means a call for a Weber! Weber is for grilling with Franks Red Hot!
PULL PLUGS & INSPECT
We will pull the spark plugs and do another leak down test to see where we are as we have some good heat in the engine.
How do we get heat in the cold?
No.1 looks lean and No.4 looks rich.
Compression Test as follows:
We TDC #4 and leak down is at 45%. Previous leak down was at 50% at way less than 100-psi.
HELLO CUSTOMER • At this point it’s time for us to call the customer with our prognoses of his ‘74 Land Cruisers F-Series engine. At some point the engine will need a rebuild. But before we go down that path, we personally would choose to get it running and see how much life is left in the engine. This way the customer can at least get to drive his “new-to-him-FJ40” for the first time. How long before the rebuild is uncertain, but at least he can get some time wheeling his rig and actually enjoy it! The customer said “OK GO! I want to drive my FJ40!” So here we go!
This Toyota F-Series engine is getting new spark plugs with six “proper” NGK spark plugs, an oil change as the original oil is old and diluted with secret sauce. The ignition needs some work, maybe with the newer Patronix. But we will see what we can do with the way it is now. The original Toyota F-Series carburetor needs a complete rebuild and fuel is leaking from various points, but it does not… DOES NOT A WEBER strapped to the intake manifold! But you may want to have a WEBER strapped inside as this 40-Series is about to be picnic ready!
The mechanical fuel pump needs sorting out as it is leaking as well. SORTED!
Once we’ve finished our “cylinder No.4 “Secret Sauce” Treatment, we flush the oil and give this F-Series Land Cruiser some good “dinosaur bones DNA” lubrication as our oil of choice is “non-Californian” real-crude fortified with real hurt feelings with real ingredients!
Because old rigs beg for the real stuff! What Types Of Engine Oil Do We Use At Red Line Land Cruisers?
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MORE 2F / SNIPER EFI RELATED READING:
• HOW TO: REVIVE AN F-SERIES ENGINE THAT HAS BEENG SITTING DORMANT? F-Series Revival Series – 1974 FJ40 Toyota Land Cruiser
• ALL IN EFFORT TO SAVE AN F!
• 2F SNIPER 101 – WHERE TO START FOR YOUR FJ40 TOYOTA LAND CRUISER?
• Add EFI To Your FJ40 Toyota 2F Toyota Engine with the Holley Sniper Kit / Redline Land Cruisers CNC Billet Manifold & Air Filter Adapter Kits
• Toyota 2F Engine – The Now Sought After 6 Cylinder Paperweight