My fj62 had the 02 sensors further back. Yours look to be on the downpipes. Now i dont have hardly any seat time in mine but i put them lower in the stream
A Super-Ultimate 3FE Diagnostics Thread - Let the Battle of Wits Begin (2 Viewers)
- Thread starter lelandEOD
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The base timing can be adjusted just as many older engines - loosening the distributor hold down bolt and turning the distributor. The ECU simply starts with the base curve and has a pre-defined amount of deviation it can induce via the preprogrammed timing maps, which are selected based on things such as engine temperature, throttle position, load, rpm, etc. On an older engine you can tune the mechanical or vacuum advance curve (changing springs, weights, etc) to mitigate such changes as EGR removal. With the 3FE you can set the base timing only, and the timing curve off of base timing is determined by the ECU.
The ECU is programmed to adjust the timing with the EGR functional - which when present and functional lowers combustion temperature, allowing more timing advance. When the EGR is removed the amount of advance the ECU is commanding can be inappropriate unless the base timing is dialed back. So for me I have my timing set so that I get no pinging at cruise load/rpm, even if it means giving up a degree or two at WOT, which I hardly use anyway.
You’ve got a lot of key things that need to be checked off the list before going further down the hole. Until you rule out the tps calibration or lack of one you’re just speculating. You have a long list of suspects. Now start doing the legwork.
I mean, you have a wb o2 sensor but are guessing at the values it’s returning...
I liked it better with the Ozone sensor
[QUOTE="lelandEOD,
If that's the case then the motor I had originally must have had non-factory exhaust. I remember looking up tear-down photos to see where they were attached when I had a shop make the exhaust.
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Maybe that’s the common link between this motor and the last one not being right
If that's the case then the motor I had originally must have had non-factory exhaust. I remember looking up tear-down photos to see where they were attached when I had a shop make the exhaust.
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Maybe that’s the common link between this motor and the last one not being right
I think the EGR theory has some merit. I also think I would check timing at idle, at 1500rpm, 2500, and 3500 just to ensure nothing funky is going on timing wise.
Pick one thing to actually rule out, perform those tests, and either celebrate or move on.
lelandEOD
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I'm not guessing at the values, I'm guessing at their average. The gauge reads a steady fluctuation of AFR from about 14.9:1 up to around 16:1... it just bobs back and forth at idle. But you're right; I need to focus on the basics first. I thought I had the TPS crossed off the list, then I realized I was running a '89-'92 TPS so I need to swap it out with the correct p/n and do it again.
I pulled the distributor tonight too and ran the diagnostics. It checked out fine.
lelandEOD
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- #51
Also... for sanity's sake, I want to confirm my timing procedure is correct.
I warm it up, place a jumper between TE1 and E1 on the check connector, turn the golden screw to temporarily get the idle to 650 (my engine idles at about 500 with the check connector shorted), set my Innova 3568 timing light to 0° and rotate the distributor to align the 7° BTDC ball bearing on the H42 flywheel with the indicator needle on the bell housing. Once this is set, tighten the distributor. So far so good, but then the FSM says to remove the jumper wire and check that the timing is at 12° BTDC. If I set my digital timing light to 12°, (with the engine at 650rpm) it's not quite there. With my light set to 12°, it looks closer to 10°. Is this normal? Am I doing something wrong?
I warm it up, place a jumper between TE1 and E1 on the check connector, turn the golden screw to temporarily get the idle to 650 (my engine idles at about 500 with the check connector shorted), set my Innova 3568 timing light to 0° and rotate the distributor to align the 7° BTDC ball bearing on the H42 flywheel with the indicator needle on the bell housing. Once this is set, tighten the distributor. So far so good, but then the FSM says to remove the jumper wire and check that the timing is at 12° BTDC. If I set my digital timing light to 12°, (with the engine at 650rpm) it's not quite there. With my light set to 12°, it looks closer to 10°. Is this normal? Am I doing something wrong?
Curious which FSM you are using and what’s the source of the 3FE? The 88’ manual is different page wise.
Reading back through your posts, My suggestion would be to step through the ECU voltage tests at some point soon. It will at least tell you if they’re at stock specs for TPS, AFM, and other sub components in the FI section.
I’m intrigued about a desmogged 3FE, I saw a few posts when researching other 3FE things just haven’t dug down on it. Seems you’ld almost require a reprogram.
You have some great minds that have posted above. I’m following this one for sure. I think there’s a lot to be said about properly desmogging an engine that Mr T designed otherwise.
Reading back through your posts, My suggestion would be to step through the ECU voltage tests at some point soon. It will at least tell you if they’re at stock specs for TPS, AFM, and other sub components in the FI section.
I’m intrigued about a desmogged 3FE, I saw a few posts when researching other 3FE things just haven’t dug down on it. Seems you’ld almost require a reprogram.
You have some great minds that have posted above. I’m following this one for sure. I think there’s a lot to be said about properly desmogging an engine that Mr T designed otherwise.
That's a tamper resistant cover over the bypass air adjustment screw in the AFM. Only relevant at idle I believe.
you do not mess with any screws when checking timing.
tps is not the problem. its calibration may be...
and you really should do the ecu voltage and continuity tests...you'd be amazed at what kind of resistance builds up at connector terminals...
just adjust the tps you have on there correctly. stop. test. re-evaluate. go back and readjust till it's dead on, or move on to the next issue. systemically rule out possibilities. right now it seems that we are simply enumerating them.
tps is far more responsible for overall performance than anyone gives credit for. and much more difficult to adjust than I can imagine, apparently.
afm is a fickle beast that should require NO MUCKING with by any one.
ISC controls air flow for idle functions.
distributor returns an engine position and speed value to the ecu.
O2 sensors return exhaust tract A/F values to the ECU> their position in relation to the head is important
ECU sends voltage pulses to injector banks front and rear and controls pulse width of fuel burst (3 cylinders each bank, simultaneously)
none of these thing can talk right if there is any issues with the wiring.
the ECU voltage test will reveal any issues with the wiring. Testing the ECU will ensure you that your head is on straight.
testing the O2 sensors should prove that they recognize the changes in A/F levels in the exhaust, AAAND that those values are reaching their destination, because you have proven the harness and ECU already.
Distributor needs next to nothing other than to be installed correctly, and on time. you verified its info is being delivered and you can check it off the list. ( you might need to hook the EGR in if you are unable to eliminate this issue with any other avenues of investigation, but I never noticed untold behavior when I had my egr system disabled.)
ICS is prolly not a contributor, but if it is not functioning properly, you might get extra air during running, or less than normal air during idle
make sure there are NO places for air to get in. even the VC gasket, oil cap, dipstick, galley gasket... ANY UNMETERED air will put this donkey into the dirt.
AFM- just use one that has not been played with. use one that has a good seal, no extra holes, and bench tests good per FSM.
(there is the tiniest possibility that you might need to make a SMALL adjustment to an AFM but if and ONLY if you are able to prove that the A/F IS OFF TRACK. most people who mess with them have not ruled out all the usual suspects before fxxxing up a perfectly good instrument, and find it was not their issue, only to have to source a new instrument.
tps...well, this bugger is pretty much the HMFWIC in the EFI department. and he's very specific about his position in life. if you put him off his throne just a red hair, he'll never let you forget that he warned you not to...
at the end of the day, I think you're reading too much into the equation. You've got added steps in your diagnostic process that aren't called for in the book. you think you have an understanding of the players in the band but there are a few places where translation has been lost. I can totally understand- as you have spent prolly spent weeks of minutes trying to get you investment to give you a reach around without any joy. it makes a man grasp for things he can understand, and shy from things he cannot.
step back.
breath
remember it is just metal, rubber, and plastic
go back to the beginning of the troubleshooting guide, and systemically check things off the list in the order of appearance. do not go down the chain till you have spent the link you're on. this system is dead simple. Toyota has already done all the research. just don't color outside of those lines.
your intake duct appears to be longer than stock. I wonder if the metal duct is also contributing to adding heat to the A/F charge. I wonder if the length and bends have created too mush static resistance to airflow.
your O2 sensors are too close to the dump. that could be affecting the type of signal the sensors read
you need more drive time with the tps to get it dialed in...people say adjust it... I say calibrate it.
you MUST check the harness for cracks, melting, poor connections.
you may need to add the EGR back to rule it out as a contributor. Yes, I said so you can rule it out...
my daily driving 3FE fj62 with H42 has a mix of 1991 fj80 parts, and 1988 fj62 parts on its EFI. I use the early ECU, and the later stuff attached to the later motor. the only things I did not swap in from the later rig were the sensors with different connectors, the PS pump and bracket, and the AC pump and bracket. I am running a 91 tps with an 88 ecu. it is not a problem.
Just throwing this variable into the heap—
The 3F-E (or any fuel injected engine) is dependent on its O2 sensors to tell it what to do about the air fuel ratio. Normally there is an air pump (smog pump) pumping extra air into the exhaust and the ECU accounts for this extra oxygen.
If the air pump is removed, the exhaust will have less (zero) oxygen in it (as can clearly be seen in any smog test report) & the O2 sensors will report this back to the ECU. The ECU without a smog pump is being told that the engine is running too rich (although it's not) so it will lean out the mixture too far.
I could be understanding this incorrectly, but I can't see how a fuel injected engine can run properly without the smog pump functioning.
Just wondering
The 3F-E (or any fuel injected engine) is dependent on its O2 sensors to tell it what to do about the air fuel ratio. Normally there is an air pump (smog pump) pumping extra air into the exhaust and the ECU accounts for this extra oxygen.
If the air pump is removed, the exhaust will have less (zero) oxygen in it (as can clearly be seen in any smog test report) & the O2 sensors will report this back to the ECU. The ECU without a smog pump is being told that the engine is running too rich (although it's not) so it will lean out the mixture too far.
I could be understanding this incorrectly, but I can't see how a fuel injected engine can run properly without the smog pump functioning.
Just wondering
