FJ62 OEM inline 6pack, worth keeping?? (1 Viewer)

4Cruisers

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Old school feeler gauge will work for the shims, I've accumulated a handful over the years. Then again, we were still using slide rules when I started college.
 

Dynosoar

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TPS adjustment is difficult and tedious. I found this was the one thing that made the biggest improvement in overall performance. I ended up buying a brand new TPS from Toyota. I made a shim stack and a test lead from an old harness I had around. Follow the steps in the FSM they are exacting and detailed if something is out of range the parts need to be replaced. My old TPS was ok in all parameters except for one and I figured it would be okay.....NO WAY! Replaced it and it was like a new engine.
Dyno
 
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TPS adjustment is difficult and tedious. I found this was the one thing that made the biggest improvement in overall performance. I ended up buying a brand new TPS from Toyota. I made a shim stack and a test lead from an old harness I had around. Follow the steps in the FSM they are exacting and detailed if something is out of range the parts need to be replaced. My old TPS was ok in all parameters except for one and I figured it would be okay.....NO WAY! Replaced it and it was like a new engine.
Dyno
Thanks! What was out of tolerance on the one you replaced?
 
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After a close study of the FSM and watching a few videos on youtube, I now understand the critical and sensitive nature of the TPS being aligned properly, as well as the need to confirm the TPS is working properly. For me to be confident that I am testing the TPS properly and potentially needing to replace it, I plan to remove the throttle body so I can do the testing and calibration on my workbench. I'm waiting for the new throttle body gasket delivery from RockAuto early next week before I disassemble.

I'll update as I go.
 

red66toy

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After a close study of the FSM and watching a few videos on youtube, I now understand the critical and sensitive nature of the TPS being aligned properly, as well as the need to confirm the TPS is working properly. For me to be confident that I am testing the TPS properly and potentially needing to replace it, I plan to remove the throttle body so I can do the testing and calibration on my workbench. I'm waiting for the new throttle body gasket delivery from RockAuto early next week before I disassemble.

I'll update as I go.
Yeah I found that having the throttle body on the bench was the best way to get it right the first time. You have better access to the screw you need to shim so you get it set perfect.
 
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It's tedious, but not difficult - take your time and you'll get it right.
fully agree. I have my multi-meter ready and waiting! I plan to go to one of the local auto parts stores to buy the feeler shims. If they are on a spinout loop, I also plan to disasembe the loop so the shims are not attached to anything. I picked up this tip from youtuber. His logic is that the weight of multiple shims pressed or bolted together was throwing off the sensitivity to the three gages of shims that need to be used. any thoughts on this point?
 

Godwin

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Best to use JIS screwdrivers rather than the usual off the shelf philip head drivers.
 
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This is a quick update on my efforts to find and destroy the gremlins in my 3FE.

Thanks to all the good advice, I taught myself how to properly calibrate the TPS. I was super hopful that the TPS was the cause of my lack of throttle response. As a point of redundancy, I hunted down a new TPS for an 88 3FE, so I had a replacement in hand if the unit in the rig was faulty. I ended up taking the throttle body off so I could test the TPS on my workbench. I also bought a set of feeler gages, my first set!

After taking the throttle body off, my attention immediately shifted to how much gunk there was on the inside of the throttle body and the intake manifold. WOW!!!!! I was expecting some issues in this regard, and had my throttle body cleaner and rubbing alcohol on the ready. What I found though, was shocking!! I spent about two hours deep cleaning the inside of the throttle body, and scrapped off some of the intake manifold, as much as I could without removing it. I then tested the TPS that was installed, though I should have done that first. The readouts on the TPS all fell within the tolerances.........which was frustrating. I elected to swap in the new TPS and calibrate it using the feeler gages. I got it dialed in.......dead on. After scraping off and replacing the gasket, and reinstalling the throttle body, I was still hopeful the combination of cleaning the TB and replacing/caliberating the TPS would solve my issues. These are the results...



1) At a dead stop, the throttle response is WILDLY better.

2) I can maintain speed on steep hills. On moderately steep hills, I can even accelerate.......which is a massive imporment.

3) The wild RPM spikes seem to be meaningfully reduced, which also seems to allow the transmission to function better.......limiting unnecessary gear shifting. I have to assume this will result in the MPG's being much improved. I will test this over the next few tanks.\

4) No longer throwing a 51 code. No codes at all.

Overall, the rig is performing on the streets, in steep hill country, MUCH MUCH better. I dont know if this is a result of the TPS being "tuned" or the throttle body being completely cleaned. It's likely that the improvement in performance is a result of both.


HOWEVER, I am still having issues. Even after the improved throttle response from a dead stop, I'm still feeling a meaningful amount of dead pedal.......meaning, after the rig is in forward motion on a flat street, if I hit the throttle in a meaningful way, RPM's drop and there is a hesitation in acceleration. This seems to be isolated to first gear. Knowing the intake manifold needs to be degunked, I plan to do this next. Also, when I'm coasting downhill, with the windows down, I can hear what sounds like a missfire coming from the muffler.... a compression release sound. Something I haven't heard before. I have had all 6 cylinders tested in the BIG engine rework that was done a few weeks back.....$4K worth, and all 6 tested as they should. New plugs, wires, and cap were installed at that time. I'm reading that my cat's might be the problem if one of them is blocked. So, a cat delete is also part of the plan when I go to replace the exhaust in a comprehensive manner.

Also, I plan to test the fuel pump, and injectors.


Any thoughts??? Thanks
 
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diesellibrarian

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As I posted in your other thread, my 62 felt like it was very "draggy" off the line as well, and it was a total dog on hills. I pulled the valve cover and found that the valve clearance was all over the map, and most of them were out of spec. After adjustment, it was like a totally new truck. Can't say this is your problem, but if you don't know when the valves were last adjusted, it needs to be on your list of things to do anyway.

(also, and maybe you mentioned this above, but how's your air cleaner looking?)
 
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As I posted in your other thread, my 62 felt like it was very "draggy" off the line as well, and it was a total dog on hills. I pulled the valve cover and found that the valve clearance was all over the map, and most of them were out of spec. After adjustment, it was like a totally new truck. Can't say this is your problem, but if you don't know when the valves were last adjusted, it needs to be on your list of things to do anyway.

(also, and maybe you mentioned this above, but how's your air cleaner looking?)

My air cleaner has been completely cleaned, and brand new OEM Air intake hoses and clamps installed. When I bought the vehicle a few months ago, these components were totally shot and had numerous cracks allowing a lot of unregistered air into the system. I also removed the throttle body, cleaned out a wild amount of GUNK from the inside, replaced the TPS and calibrated using the correct feeler gages.....I was able to get it extremely dialed in. All of this has helped a great deal for sure!! No codes being thrown now.

Valve adjustment and timing next on my list.
 
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Ok....., here is an update Would love any advise!


This is a short recap of what all has been done up until now. Again, this is short list of the points that could be contributing to my lack of power, and is in no particular order.

1) Valves have been adjusted properly.
2) Timing was reset to factory specs, 7 degrees BTDC. (However, I have read on several other threads that the 3FE is the happiest with the timing advanced to between 12-14 degrees. I figure I might adjust the timing to 12-14 degrees after getting this sucker running as it should. My opinion is that this adjustment is a means of optimizing performance but most likely not the cause of my lack of power.
3) New Plugs, wires, and distributor.
4) All oil leaks have been properly addressed having replaced nearly every seal.....including the main rear seal. (There isn't one drop of oil coming from this sucker which was a major effort considering it was leaking oil from practically every possible point)
5) All 6 cylinders have been compression tested and check out.
6) TPS replaced and highly calibrated. Throttle body removed, well cleaned, and reinstalled with a new gasket.
7) SMOG system disabled using BB's. (I have a complete Desmog kit in-hand, with plans to comprehensively remove the Smog system components)
8) Throttle cable checked, cleaned and adjusted.
9) Air cleaner inspected, cleaned, new air filter new OEM air hoses and ring clamps installed.
10) Both Cats have been cut out. When I bought this sucker, one of the cats had been replaced with a generic cat, the one on the outside of the frame rail. The cat on the inside of the frame is original. The cats were cut out with the intention of running temporary straight pipes, until I have the rig running properly, at which point I plan to install the Otramm FJ62 single cat stainless system. NO surprise that the one original cat was almost complete blocked. This gave me great hope that the main problem had been identified....Nope!!!!

After all this and more, the net result is that when the rig is on the rack, it sounds and feels like it's running properly. The throttle has an immediate response, and it runs through the gears like it should. However, off the rack, under load.....the black hole of power remains, and almost feels worse!!!!! All of the this work needed to be done to optimize performance, but I have not identified what is causing the main power issue.

What I have left on my list.....
1) My mechanic, who is also scratching his head big time, is going to check the transmission oil pressure next week. It's possible the transmission is failing and causing the lack of power........right?
2) Fuel injectors may need to be replaced, but if this was the cause of my power issues, I think it would run poorly on and off the rack, right!!??
3) The vacuum lines have been inspected by hand, but I'm going to do a "smoke injection" into the vacuum system to visually identify any leaks.
4) I have identified an exhaust leak at block due to a bolt head at the exhaust manifold having sheared off somehow. When I go to install the new exhaust, I will address this, but I don't think this is my main issue.
5) I'm going to do a high level inspection of the wiring harness. I have done a cursory inspection and found no visible damage.

Past this, my only remaining idea is that the ECU is faulty. Is this possible??? Has anyone had an ECU fail and cause power issues???

Any suggestions as to what I may be leaving out here?????

Thanks all.
 

Spook50

My daughter likes Stitch
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This is a quick update on my efforts to find and destroy the gremlins in my 3FE.

Thanks to all the good advice, I taught myself how to properly calibrate the TPS. I was super hopful that the TPS was the cause of my lack of throttle response. As a point of redundancy, I hunted down a new TPS for an 88 3FE, so I had a replacement in hand if the unit in the rig was faulty. I ended up taking the throttle body off so I could test the TPS on my workbench. I also bought a set of feeler gages, my first set!

After taking the throttle body off, my attention immediately shifted to how much gunk there was on the inside of the throttle body and the intake manifold. WOW!!!!! I was expecting some issues in this regard, and had my throttle body cleaner and rubbing alcohol on the ready. What I found though, was shocking!! I spent about two hours deep cleaning the inside of the throttle body, and scrapped off some of the intake manifold, as much as I could without removing it. I then tested the TPS that was installed, though I should have done that first. The readouts on the TPS all fell within the tolerances.........which was frustrating. I elected to swap in the new TPS and calibrate it using the feeler gages. I got it dialed in.......dead on. After scraping off and replacing the gasket, and reinstalling the throttle body, I was still hopeful the combination of cleaning the TB and replacing/caliberating the TPS would solve my issues. These are the results...



1) At a dead stop, the throttle response is WILDLY better.

2) I can maintain speed on steep hills. On moderately steep hills, I can even accelerate.......which is a massive imporment.

3) The wild RPM spikes seem to be meaningfully reduced, which also seems to allow the transmission to function better.......limiting unnecessary gear shifting. I have to assume this will result in the MPG's being much improved. I will test this over the next few tanks.\

4) No longer throwing a 51 code. No codes at all.

Overall, the rig is performing on the streets, in steep hill country, MUCH MUCH better. I dont know if this is a result of the TPS being "tuned" or the throttle body being completely cleaned. It's likely that the improvement in performance is a result of both.


HOWEVER, I am still having issues. Even after the improved throttle response from a dead stop, I'm still feeling a meaningful amount of dead pedal.......meaning, after the rig is in forward motion on a flat street, if I hit the throttle in a meaningful way, RPM's drop and there is a hesitation in acceleration. This seems to be isolated to first gear. Knowing the intake manifold needs to be degunked, I plan to do this next. Also, when I'm coasting downhill, with the windows down, I can hear what sounds like a missfire coming from the muffler.... a compression release sound. Something I haven't heard before. I have had all 6 cylinders tested in the BIG engine rework that was done a few weeks back.....$4K worth, and all 6 tested as they should. New plugs, wires, and cap were installed at that time. I'm reading that my cat's might be the problem if one of them is blocked. So, a cat delete is also part of the plan when I go to replace the exhaust in a comprehensive manner.

Also, I plan to test the fuel pump, and injectors.


Any thoughts??? Thanks
Cleaning the throttle body makes a HUGE difference, to be sure, as well as properly adjusting the TPS. I also did mine on the bench, along with a thorough cleaning of every tiny minuscule passageway in the throttle body. I also gave the idle speed control a good cleaning around the plunger so that it would function properly, along with cleaning out the adjustment screw's passageway, the screw itself, and replacing its O ring. Result when reinstalling was a MUCH higher idle than before cleaning, which I got dialed down to 700 RPM when hot (though sometimes it randomly idles at 900RPM under normal conditions while driving. Then I'll be stopped at another light shortly after and it'll be idling at 700 RPM. I'm suspecting the ISC might be having issues but haven't seriously troubleshot it yet), and far better overall performance. Fuel economy IIRC stayed about the same on average.
 
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Here is a quick update on my FJ62 lack of power deep dive......

-Transmission maintains proper fluid pressure. Great!

-Fuel Pump operating exactly as it should. Also, the fuel pressure is maintained for many hours after the system is shut down, which indicates there are no fuel pressure leaks. Also great!

-Big problems with the remainder of the fuel system. The fuel dampener and regulator are both totally shot. I suppose it's not out of the questions that these two failing combined could be the source of my "dead pedal".....or lack of power / throttle response. Thoughts?

The new plan of action is to replace the fuel dampener and regulator. In addition, while we have the fuel delivery system disassembled, we'll swap out the fuel injectors for a re-manufactured OEM set.

Figures crossed that the primary reason for my lack of power is related to the fuel delivery system issues!!!!
 
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Stop the madness and swap it! I did and will never look back LQ9 6.0....doubled the gas mileage, dropped 500 lbs in weight and tripled the horsepower with v8 bone stock. I'm now 10 years plus later and rebuilding it frame off.....will just rebuild 6.0 and add a small cam. Love it! it will be my daily! Follow Besty Build . I would have loved to go back with a Toyota but just not worth the extra money. rebuild a 2001-2004 Tundra 4.7 maybe. Go this far gotta make it a FJ142 and swap frame with an 80 or use a Tor kit. Just MHO
 
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Stop the madness and swap it! I did and will never look back LQ9 6.0....doubled the gas mileage, dropped 500 lbs in weight and tripled the horsepower with v8 bone stock. I'm now 10 years plus later and rebuilding it frame off.....will just rebuild 6.0 and add a small cam. Love it! it will be my daily! Follow Besty Build . I would have loved to go back with a Toyota but just not worth the extra money. rebuild a 2001-2004 Tundra 4.7 maybe. Go this far gotta make it a FJ142 and swap frame with an 80 or use a Tor kit. Just MHO
Madness is a perfect description!!! I have been considering an LS swap. At this point, I'm on a mission to get this 3FE running like it should so I can get a feel for the rig, what it can and can't do. If I can get the dang thing to run correctly, I'm sure it will meet my expectations....which are apt for an '88 inline 6. I'm not expecting to own the road or the trail in this one, that's what my 06 LC 100 is for ;))) Ultimately, I think the inline 6 pack is cool and would like to play with it for a while.
 
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ok...:) by all means carry on, and enjoy! Regardless, absolutely the best truck on the road. Just in love.... in a real unhealthy way with mine!🤣
 

Spook50

My daughter likes Stitch
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Madness is a perfect description!!! I have been considering an LS swap. At this point, I'm on a mission to get this 3FE running like it should so I can get a feel for the rig, what it can and can't do. If I can get the dang thing to run correctly, I'm sure it will meet my expectations....which are apt for an '88 inline 6. I'm not expecting to own the road or the trail in this one, that's what my 06 LC 100 is for ;))) Ultimately, I think the inline 6 pack is cool and would like to play with it for a while.
Can't argue against either of you lol. There comes a point when it becomes personal.
 
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EUREKA!!!!! Got the '88 FJ62 back from the mechanic today. After a ton of trouble shooting by the two of us over several months, and multiple rounds of repair and replacement, it seems we finally got to the root of my lack of power. This is not to say all the work prior to this latest round was not needed, just the opposite. I'm confident that the extremely poor performance was caused by a combination of several well needed points of repair.

It seems the final piece of this maddening puzzle came down to the fuel delivery system.

This is what we did over the last few weeks:
-Replaced the fuel regulator , which was totally shot
-Replaced the fuel dampener, also totally shot
-Replaced all six injectors. This was a point of good measure as we did not test each injector prior to replacement.

In addition, while the rig was torn down we did the following:
-Comprehensively removed my "BB BLOCKED" smog system and installed a lermscustoms.com de-smog kit.
-Welded up a temporary set of straight pipes where the cat's use to be.
-Advanced the timing to 11.

I filled her up with 91 octane, and POW!!!!!! Boy of boy, that did the trick!!! The ol'lady came back to life and is mean has heck. Three weeks ago I was having trouble maintaining 60mph on the interstate. Today, I was easily doing 90 and maintaining 80 on long stretches of mild inclines. On neighborhood streets with STEEP inclines that previously caused me to have to stop and drop the T-case into LOW, today I was able to easily drive them and even accelerate. My MPG was averaging around 5 so I'm expecting massive improvements and will report back after I have cycled through a few full tanks.

My estimation is that because the fuel dampener and regulator were both failing, the system was dumping far too much fuel into the cylinders. The engine was drowning.
To answer my own question, Is the OEM inline 6pack worth keeping....YES. FOR SURE. Now that the rig is performing as good or possibly better than intended, I can now proceed with the build-out I had in mind from day one, however, I think I will drive it just like it is for a few months and finally take it on some trail rides....really get to know her before doing the lift and 33's.

A BIG thanks to Jason at J&M Auto in Westfork AR. And, a BIG thanks to all you MUDDERS who gave me advice. I look forward to paying it forward with other 60/62 owners, happily!!
 
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Fayetteville AR
After another day driving around Fayetteville AR,, on steep city streets, this rig is a monster!! No worries at all it will push 33's with ease. While it's not fast, which I didn't expect or find important for my needs, I can now feel the torque. Torque in spades baby!!!! It feels like it wants to climb a brick wall!! Like I said, mean as heck!!!

Question. At a rolling stop, when I hit the 4H button, the T-case gears grind in a meaningful way. just for a half second. At a full stop, no issues at all. Also, at a rolling stop, disengaging the 4H, nada. No grinding, no sound, no vibration at all. Is the gear grinding at 5-10 MPH expected, or should I avoid this by just coming to a full stop. This point doesn't affect me at all or the way I will use the rig. But, given all the drivetrain work, I want this sucker to behave as it should.
 
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