fj62--3FE idle problems finally fixed!! (2 Viewers)

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I've had my 62 since last May, and have been slowly working my way through all the issues that have accrued over the years--everything from minor rust issues to cooling system issues, to charging system failure, etc. Before I found MUD, and before the realization finally sank in that I was going to need to maintain this thing myself, I took it to an independent mechanic and then a Toyota dealer, to try to get a nagging rough idle fixed. A few hundred dollars later, it wasn't any better than before. The idle sat around 900 rpm (I thought maybe the tach was reading a little high) and was not smooth. Every 3 or 4 seconds it would cut out for a split second, and then come back.

Searching MUD eventually led me to the thread in the FAQ section about the Fuel Pulsation Dampener. I checked mine, and sure enough, the screw was out. I thought HaHa this must be it! I screwed it in, but no help. I noticed fuel stains around the dampener and so decided to just replace it. After I replaced the dampener, the idle cut out went away, but it still did not idle smooth and the idle sat around 900 rpm even after it was warmed up.

Today, I decided to just start going through all the EFI system checks. To begin with, I figured I'd put the ECU in diagnostic mode just to say I had done it. The Check Engine light had not been coming on (other than when the key was first turned on), so I hadn't felt the need to do this previously. I stuck the paper clip in the holes and went around to take a peak at the blinking light. Low and behold, I had an error! An error 51. The FSM pointed to several things that could cause this problem, but I was pretty sure they were all OK--except for the throttle position sensor. I wasn't sure about that. So I popped the connector off and did the resistance check as detailed on page FI 69. I had a problem! the IDL-E2 check with the throttle closed was infinite ohms. By loosening the screws, I turned the Throttle Position Sensor until I got a IDL-E2 reading with the throttle closed. Opened the throttle a little and the reading went to infinite like it is supposed to. Connected everything back up and started it up. Idled smooth as silk at about 800 rpm. After it warmed up for a few minutes, the idle dropped right down to about 650, just like the book says. And it was just purring along. I couldn't believe it!

So I learned my lesson. Number one: I am my own mechanic for this rig. Number 2: My first step in trouble shooting anything engine related is to check ECU diagnostics.

And yes I cleared the error, and then rechecked again after I ran the engine for awhile, and the error is all gone. Yippee!!!
 

RockDoc

I'll take Bruce Vilanch for the block.
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Awesome, I had a nagging high idle issue that was cleared with some attention to the TPS as well. That FSM pays for itself the first time you work on the truck, plus, you don't wait for things to get back before you give them some attention. Just flip through it and see what might be up.
 

Rigger

Ramble Tamble
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Nice going, man! My '62 will idle okay, but I have thought that it could be a smoother idle. I will look at this closer.

I agree with you (and most other mudders); it is best to be your own Cruiser mechanic.
 
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neither are mine!! slowly but surely. i to have a high idle and when i shut the engine off it makes this weird airy farty sound (best description i can come up with). and when i put the rig in gear, it goes in hard. idle is at roughly 1100. thoughts?
 
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neither are mine!! slowly but surely. i to have a high idle and when i shut the engine off it makes this weird airy farty sound (best description i can come up with). and when i put the rig in gear, it goes in hard. idle is at roughly 1100. thoughts?

Can't help you with the farty sound, but as I discovered, the idle is influenced by the Throttle Position Sensor. Put the ECU in diagnostics mode and check for any errors. Do the resistance checks for the Throttle Position Sensor per page FI 69 in the Factory Service Manual. It made a world of difference for me.

It's going in gear hard because it's idling high. If it is also clunking (especially going from Reverse to Drive), that my be a sign of some wear on the transmission output shaft. That test is also in the FSM.
 
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hey slcfj62

hey slcfj62, i am having the exact problem with my 89' fj62. i have read alot on readjusting the TPS and it is probably bad but before i replace with a new one i want to check mine first.......so i was wondering if you had to drain your coolant and pull apart the throttle body assembly just to adjust it?(fsm says yes) i am wondering if you can remove the electrical harness in front of it blocking the sensor and do no harm to engine and adjust the TPS thus bypassing the removal of throttle body and draining of coolant? or just tell me how you did it? sorry this is so much i am asking.

p.s. if you do have to remove the throttle body to adjust it........... when you adjust the TPS attached to the throttle body, when you open the throttle with the lever it makes the ohmage go up and down? again sorry for the dumb ?'s. thanx if you can reply
 
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hey slcfj62, i am having the exact problem with my 89' fj62. i have read alot on readjusting the TPS and it is probably bad but before i replace with a new one i want to check mine first.......so i was wondering if you had to drain your coolant and pull apart the throttle body assembly just to adjust it?(fsm says yes) i am wondering if you can remove the electrical harness in front of it blocking the sensor and do no harm to engine and adjust the TPS thus bypassing the removal of throttle body and draining of coolant? or just tell me how you did it? sorry this is so much i am asking.

p.s. if you do have to remove the throttle body to adjust it........... when you adjust the TPS attached to the throttle body, when you open the throttle with the lever it makes the ohmage go up and down? again sorry for the dumb ?'s. thanx if you can reply

I didn't drain the coolant or remove the throttle body. The bottom screw on the TPS is the problem child. I didn't have an angle screw driver, so I had to take the piece off that bolts on directly in front of the TPS (to the right of the TPS if you are standing on the side with the air cleaner). Be careful not to mess up the gasket. You can't move it very far because it has some little coolant lines attached to it. But you can move it away far enough to get a long screw driver into the bottom screw. Pop the electrical connector off of the TPS and measure the resistance (ohms) between the IDL and the E2 pins as you rotate the TPS. With the throttle closed, you should get a resistance measurement. Then if you open the throttle a little bit, the resistance goes to infinite. Close the throttle and you should get a measurement again. Tighten down the screws and put it back together. In my case, the IDL-E2 resistance with the throttle closed was way less than the maximum specified in the FSM. After I did this to mine, the idle smoothed right out, idled lower, and dropped to 650 rpm after it warmed up.

As far as the other TPM resistance values, the only one that should change (other than IDL) is the VTA pin. It should vary smoothly between about zero and whatever your VC-E2 resistance is as you open and close the throttle.

Good luck.
 
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thanx

i cant thank you enough for clearing that up for me. i thought that would be a little much to remove the coolant and throttle body just to adjust the TPS. so you can pull that thing out enough to adjust it,gr8. is the one you adjusted the original oem toyota TPS ...............i'm wondering if i should expect mine to readjust w/o replacing with new one.(mine is oem)

Well i thank you for all your help slcfj62, God bless
 
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One never knows on a rig this old, but it looked old enough to be OEM. Leastways I didn't replace it. Just adjusted it. I did learn that it won't come apart, so don't try. If it's bad, just replace it and be done with it. But mine adjusted just fine.

And God bless us everyone.
 
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i cant thank you enough for clearing that up for me. i thought that would be a little much to remove the coolant and throttle body just to adjust the TPS. so you can pull that thing out enough to adjust it,gr8. is the one you adjusted the original oem toyota TPS ...............i'm wondering if i should expect mine to readjust w/o replacing with new one.(mine is oem)

Well i thank you for all your help slcfj62, God bless

You wouldn't need to drain the coolant to pull the throttle body. Only a little coolant will come out when you disconnect the two hoses, just need a paper towel. There are advantages to pulling the throttle body:
-it'll be totally gummed up inside, so much so that the throttle may not close all the way, and there may be blocked vacuum passages
-you should remove and clean the TPS (with throttle body cleaner, not carb cleaner), it may be gummed up and not turning properly too
- easier to test and adjust the tps on the bench

Bill
 
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You wouldn't need to drain the coolant to pull the throttle body. Only a little coolant will come out when you disconnect the two hoses, just need a paper towel. There are advantages to pulling the throttle body:
-it'll be totally gummed up inside, so much so that the throttle may not close all the way, and there may be blocked vacuum passages
-you should remove and clean the TPS (with throttle body cleaner, not carb cleaner), it may be gummed up and not turning properly too
- easier to test and adjust the tps on the bench

Bill

Can't argue with that. My throttle body was recently cleaned, so I didn't need to do it again. I took the TPS off to test it, and it turned smoothly.
 
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well guys today i tried to adjust the TPS and i could get a reading from the idl and e2 pin. i could get a reading from any other pin and e2 but not idl and e2. do ya'll have any pic of what the TPS looks like in the perfect adjusted position? i think i just need to buy a new TPS, but now my cruiser, in park, idles nice and low but wont accelerate past 1800 and then cuts out and in at 1800 if i hold the accelerator and then it wants to die. it is throwing code 41. any reason why i couldnt get a reading on the idl-e2? a picture would be great of where the set screws are at on the adjustment. sorry for the inconvenience if you guys can chime in. any advice would be gr8.(need serious help though,lol. if i get a new one....i shouldnt have a problem adjusting it with a ohm meter right?)
 

PabloCruise

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This is all I can show you from work.

I can put up FSM scans re TPS when I get home...

FWIW, I cannot get my replacement TPS to spec out either :frown:
tps2.gif
 
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thanx for the help pablo cruise. everytime i hook multimeter to the idl and e2 i get nothing, not infinity nor any reading, the meter just sits. are you having this problem also with the new tps ? is it new or a used replacement? thanx for anything you can provide pabloecruis, l8r
 
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thanx for the help pablo cruise. everytime i hook multimeter to the idl and e2 i get nothing, not infinity nor any reading, the meter just sits. are you having this problem also with the new tps ? is it new or a used replacement? thanx for anything you can provide pabloecruis, l8r

Even when you loosen the screws and rotate the TPS?
 

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