Vf signal
07-11-2007, 01:42 PM
#1
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Vf signal
I ran a couple lines into my truck so I can monitor my Vf signal on my 22re.
Got the idea from
http://www.well.com/user/mosk/Vfsignal.htm
Everything reads good, except at WOT I read 0. Now it mentions something about this on the page, but it doesn't specify if this is normal or not. Anyone know if this is supposed to happen? At WOT does the ECU just ignore the o2 sensor?
on a side note as a result of this experiment, seems like I might need a 4-wire heated o2 sensor. I installed a doug thorley header (non-ceramic) and it doesn't seem to keep my sensor hot enough. Fine for normal driving, but at idle I often don't pick up a reading. Thinking I should get a heated sensor so it's always getting a reading?
Got the idea from
http://www.well.com/user/mosk/Vfsignal.htm
Everything reads good, except at WOT I read 0. Now it mentions something about this on the page, but it doesn't specify if this is normal or not. Anyone know if this is supposed to happen? At WOT does the ECU just ignore the o2 sensor?
on a side note as a result of this experiment, seems like I might need a 4-wire heated o2 sensor. I installed a doug thorley header (non-ceramic) and it doesn't seem to keep my sensor hot enough. Fine for normal driving, but at idle I often don't pick up a reading. Thinking I should get a heated sensor so it's always getting a reading?
06-09-2017, 09:25 PM
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Wished I had found out about the Vf signal a long time ago. Takes the guess work out of trying to adjust the AFM and that little idle mixture screw (air bypass screw next to the AFM). I, also, ran two wires from the VF1 and E1 terminals to the inside of the cab, and watched the voltage fluctuate as I drove. Took a lot of patience getting the adjustments right, but I finally have my truck running where VF1 stays at 2.5v (actually 2.2v) much of the time. The engine (1995 3.0) has never run better since I've owned it. Idles smoother, too. For the OP's question, I haven't tried WOT, yet. Just had the tranny rebuilt, and I don't want to be too hard on it right now.
06-11-2017, 11:08 AM
#5
Registered User
I get "0V" (only the LEFT LED is lit which is the power led) under WOT conditions
Which - according to the manual is "open loop" condition (operating purely on the table look up, not using the 02 for feedback)
Also, not surprisingly, the 02 sensor does not "scroll"
https://www.well.com/user/mosk/Vfsignal.htm
Which - according to the manual is "open loop" condition (operating purely on the table look up, not using the 02 for feedback)
Also, not surprisingly, the 02 sensor does not "scroll"
https://www.well.com/user/mosk/Vfsignal.htm
04-25-2018, 10:44 PM
#6
Reviving
Hello, I came across this thread while searching and decided to revive it instead of creating a new thread. I’m a long time lurker but haven’t posted much so please gently correct me if this isn’t the best way of going about it.
Here goes, I’d like to read the Vf signal because I’ve been running rich for a while (based on mileage and gas smell in the exhaust). I think the Vf might help me see what the ecu is seeing and doing. My 22re was rebuilt by a PO with a crower cam, thorley header and stainless exhaust w/o a cat (gonna add one once I stop it running rich). I’ve got the early 22re with round diagnostic connectors and I believe it’s the original engine in it (or at least another early 22re). I added a 4 wire heated O2 sensor to hopefully cure the rich condition, it helped but didn’t cure it.
My question is where is the Vf signal on an 85 22re and how do I read the stored value? Can I run a wire and hook up to it to run a narrow band air fuel gauge?
I believe the Vf connector is somewhere in the larger round plug near the driver side fender but I’m not sure which spade connector it is. Ive got the fsm but it simply tells you to connect a SST to the plug to read the O2 sensor. I’ve looked all over yotatech, 4crawler’s site, mud and the links above. I haven’t gotten a clear answer for the early 22re and I’m not sure of the proper procedure.
Thanks and sorry for the naivety and long reply.
Winky
Here goes, I’d like to read the Vf signal because I’ve been running rich for a while (based on mileage and gas smell in the exhaust). I think the Vf might help me see what the ecu is seeing and doing. My 22re was rebuilt by a PO with a crower cam, thorley header and stainless exhaust w/o a cat (gonna add one once I stop it running rich). I’ve got the early 22re with round diagnostic connectors and I believe it’s the original engine in it (or at least another early 22re). I added a 4 wire heated O2 sensor to hopefully cure the rich condition, it helped but didn’t cure it.
My question is where is the Vf signal on an 85 22re and how do I read the stored value? Can I run a wire and hook up to it to run a narrow band air fuel gauge?
I believe the Vf connector is somewhere in the larger round plug near the driver side fender but I’m not sure which spade connector it is. Ive got the fsm but it simply tells you to connect a SST to the plug to read the O2 sensor. I’ve looked all over yotatech, 4crawler’s site, mud and the links above. I haven’t gotten a clear answer for the early 22re and I’m not sure of the proper procedure.
Thanks and sorry for the naivety and long reply.
Winky
Last edited by Winky29; 04-25-2018 at 10:45 PM.
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04-26-2018, 04:04 PM
#8
Thanks for your reply CO_94_PU, that pic is really helpful. Just to be sure I understand the procedures. To read stored A/F value I would warm the engine up, leave TE1 open and connect Vf in the connector pictured to bare metal. To read the O2 sensor I'd warm up engine, ground TE1 run the engine at 2500 rpm and connect O2 to Vf. I'd look for the O2 to cycle at least 8 times in 10 seconds (per FSM).
Some additional questions
1. So if I wanted to set up a narrow band A/F gauge I'd need to run a wire from Vf to the gauge and run a ground wire from the gauge to ground, correct?
2. I know that TE1 is in the 2 connector round plug but I'm not sure which one it is (Green--yellow or brown), does anyone know? I guess I could just guess and check, its a 50/50 shot.
3. Lastly, does anyone know which wire is what in the 3 plug connector? Would this be in the electrical diagram? I do not have a copy of the electrical diagrams, just what is in the FSM. I'd love something like the image RJR posted for the early 22RE.
Thanks again,
Winky
Some additional questions
1. So if I wanted to set up a narrow band A/F gauge I'd need to run a wire from Vf to the gauge and run a ground wire from the gauge to ground, correct?
2. I know that TE1 is in the 2 connector round plug but I'm not sure which one it is (Green--yellow or brown), does anyone know? I guess I could just guess and check, its a 50/50 shot.
3. Lastly, does anyone know which wire is what in the 3 plug connector? Would this be in the electrical diagram? I do not have a copy of the electrical diagrams, just what is in the FSM. I'd love something like the image RJR posted for the early 22RE.
Thanks again,
Winky
Last edited by Winky29; 04-26-2018 at 04:06 PM.
04-26-2018, 06:08 PM
#9
To read the O2 sensor I'd warm up engine, ground TE1 run the engine at 2500 rpm and connect O2 to Vf. I'd look for the O2 to cycle at least 8 times in 10 seconds (per FSM).
Not covered in the linked document. I'd expect it to fluctuate as described rich-lean-rich.
Some additional questions
1. So if I wanted to set up a narrow band A/F gauge I'd need to run a wire from Vf to the gauge and run a ground wire from the gauge to ground, correct?
2. I know that TE1 is in the 2 connector round plug but I'm not sure which one it is (Green--yellow or brown), does anyone know? I guess I could just guess and check, its a 50/50 shot.
3. Lastly, does anyone know which wire is what in the 3 plug connector? Would this be in the electrical diagram? I do not have a copy of the electrical diagrams, just what is in the FSM. I'd love something like the image RJR posted for the early 22RE.
Thanks again,
Winky
1. So if I wanted to set up a narrow band A/F gauge I'd need to run a wire from Vf to the gauge and run a ground wire from the gauge to ground, correct?
2. I know that TE1 is in the 2 connector round plug but I'm not sure which one it is (Green--yellow or brown), does anyone know? I guess I could just guess and check, its a 50/50 shot.
3. Lastly, does anyone know which wire is what in the 3 plug connector? Would this be in the electrical diagram? I do not have a copy of the electrical diagrams, just what is in the FSM. I'd love something like the image RJR posted for the early 22RE.
Thanks again,
Winky
2, this era uses T and E(e1) they are both in the two place plug seen above (with the SST wrapped around it)
3, not sure off hand what signal is on those three wires or the single wire.. Easy enough to measure connection at the ECU and reference the ECU pinout
04-26-2018, 06:30 PM
#10
Thanks again,
I misspoke when I said connect to ground, I meant to say read the voltage by connecting the + side of the volt meter to Vf and the other probe to ground. I definitely wouldn’t want to ground it directly.
I’ll check the Vf signal as described and go from there. I had thought of getting a catalytic converter with a sensor bung and wiring up an A/F meter to that, could go with a wide band setup. Would I get an accurate signal at the front of the cat (before the filter media)?
Thanks again,
Winky
I misspoke when I said connect to ground, I meant to say read the voltage by connecting the + side of the volt meter to Vf and the other probe to ground. I definitely wouldn’t want to ground it directly.
I’ll check the Vf signal as described and go from there. I had thought of getting a catalytic converter with a sensor bung and wiring up an A/F meter to that, could go with a wide band setup. Would I get an accurate signal at the front of the cat (before the filter media)?
Thanks again,
Winky
04-27-2018, 05:05 PM
#13
Back with another question. I wasn’t sure if I should just PM CO_94_PU or post here but decided to post here so others might benefit.
I tested the Vf signal as described. With the engine running the number bounced up and down from 0.1 to 0.9 volts. When I shut off the engine I got a steady reading of .020v.
Am I correct to assumed the fluctuation I saw was the O2 sensor acting normally and the stored Vf value is .020v (running rich)?
If that’s the case I’m going to try adjusting the spring on my afm. I know the afm needs replacing because it failed the dynamic resistance test, per 4crawlers directions. I’ve had one on order since October. It looks like it was opened at some point and may have been reset.
Thanks,
Winky
I tested the Vf signal as described. With the engine running the number bounced up and down from 0.1 to 0.9 volts. When I shut off the engine I got a steady reading of .020v.
Am I correct to assumed the fluctuation I saw was the O2 sensor acting normally and the stored Vf value is .020v (running rich)?
If that’s the case I’m going to try adjusting the spring on my afm. I know the afm needs replacing because it failed the dynamic resistance test, per 4crawlers directions. I’ve had one on order since October. It looks like it was opened at some point and may have been reset.
Thanks,
Winky
04-27-2018, 07:27 PM
#14
Back with another question. I wasn’t sure if I should just PM CO_94_PU or post here but decided to post here so others might benefit.
I tested the Vf signal as described. With the engine running the number bounced up and down from 0.1 to 0.9 volts. When I shut off the engine I got a steady reading of .020v.
Am I correct to assumed the fluctuation I saw was the O2 sensor acting normally and the stored Vf value is .020v (running rich)?
If that’s the case I’m going to try adjusting the spring on my afm. I know the afm needs replacing because it failed the dynamic resistance test, per 4crawlers directions. I’ve had one on order since October. It looks like it was opened at some point and may have been reset.
Thanks,
Winky
I tested the Vf signal as described. With the engine running the number bounced up and down from 0.1 to 0.9 volts. When I shut off the engine I got a steady reading of .020v.
Am I correct to assumed the fluctuation I saw was the O2 sensor acting normally and the stored Vf value is .020v (running rich)?
If that’s the case I’m going to try adjusting the spring on my afm. I know the afm needs replacing because it failed the dynamic resistance test, per 4crawlers directions. I’ve had one on order since October. It looks like it was opened at some point and may have been reset.
Thanks,
Winky
Edit: sorry misspoke..
You may have a fuel pressure issue, or leaking injectors, still easy to check the fuel pressure.. What the zero to one volt VF trim is reporting is an over rich condition, however it isn't outside of the trim limits of the ECU. Once it goes out of bounds it will throw the "over rich" trouble code, at which point the ECU is unable to remove any more one time from the injector pulses.
Last edited by Co_94_PU; 04-27-2018 at 10:20 PM.
04-27-2018, 10:07 PM
#15
Let us revisit your primary issue before you go modifying things..
You have a fuel odor and poor mileage as well no cat pack..
How healthy is the ignition system? You will need the little adjustable tester that measures the spark by its arc length (and color/temperature, also a factor).
What plugs are you running and at what gap? Have they been checked or changed recently?
Exactly what are the specs on that aftermarket cam shaft, do you even know its "stage"...?
You aren't throwing a code for over rich, which means the ECU is doing its job and not hitting it's limits. This basicly means the system is working and your HC smell is likely due to a missing cat.
It is quite possible the previous owner tweaked the vafm for a richer fuel mixture per instructions on the cam, also likely they did it to hide a pre-ignition issue.
I can dig out and into the TCCS document but without some background it would only be assumption and guessing.
You have a fuel odor and poor mileage as well no cat pack..
How healthy is the ignition system? You will need the little adjustable tester that measures the spark by its arc length (and color/temperature, also a factor).
What plugs are you running and at what gap? Have they been checked or changed recently?
Exactly what are the specs on that aftermarket cam shaft, do you even know its "stage"...?
You aren't throwing a code for over rich, which means the ECU is doing its job and not hitting it's limits. This basicly means the system is working and your HC smell is likely due to a missing cat.
It is quite possible the previous owner tweaked the vafm for a richer fuel mixture per instructions on the cam, also likely they did it to hide a pre-ignition issue.
I can dig out and into the TCCS document but without some background it would only be assumption and guessing.
04-27-2018, 11:23 PM
#16
The engine was rebuilt about 6k miles ago by the previous owner. The exhaust was replaced with the Thorley ceramic coated header and stainless 2.25" pipes. Ignition system seems pretty good, although I haven't tested the spark.
Plugs NGK V-Power plugs gaped to spec from FSM about 2k miles ago.
Wires NGK newer probably when rebuilt
Cap and rotor are OEM, probably replaced when rebuilt
Cam is a Crower Stage 2 cam (pn 61807) INT/EXH - Dur @ .050” Lift: 216°/220° RR: 1.5/1.5Gross Lift: .430”/.430” LSA: 114° RPM: 2000 to 6000 Redline: 6500
Timing set to 5 degrees BTDC with tester jumpered
It idles fairly smooth at a little under 800 rpm
Other possibly related symptoms are rumbling on deceleration (not backfiring, this could be related to the less restrictive exhaust) and poor fuel economy I average 13 mpg over the last 15 months in Honolulu traffic.
I will reset the ECU and see what I get from Vf.
Thanks,
Winky
Plugs NGK V-Power plugs gaped to spec from FSM about 2k miles ago.
Wires NGK newer probably when rebuilt
Cap and rotor are OEM, probably replaced when rebuilt
Cam is a Crower Stage 2 cam (pn 61807) INT/EXH - Dur @ .050” Lift: 216°/220° RR: 1.5/1.5Gross Lift: .430”/.430” LSA: 114° RPM: 2000 to 6000 Redline: 6500
Timing set to 5 degrees BTDC with tester jumpered
It idles fairly smooth at a little under 800 rpm
Other possibly related symptoms are rumbling on deceleration (not backfiring, this could be related to the less restrictive exhaust) and poor fuel economy I average 13 mpg over the last 15 months in Honolulu traffic.
I will reset the ECU and see what I get from Vf.
Thanks,
Winky
04-28-2018, 07:25 AM
#17
History tells us the 22r series doesn't like these modern style spark plugs. The grooved plugs are designed/intended to fire on one side of the groove then alternate to the other. This has effects on the flame front that the engine designers did not account for while tuning the combustion chamber shape. Combine this with altered cam specs, unknown sparkplug "clocking", it would be possible the shockwave of the flame front is pushing the air fuel mixture out the exhaust valve before combustion has reached to point the design expects. The result is less power and less fuel efficiency.
Start with the proper spec plugs.
Start with the proper spec plugs.
04-28-2018, 09:49 AM
#18
I thought the NGK V-powers we’re stock replacement. I read through a bunch of threads on which plugs to run and the NGK plugs were said to be as good as the Denso. I’ll pick up some Denso at the stealership and go from there.
Thanks,
Jared
Thanks,
Jared
04-28-2018, 11:15 AM
#20
Registered User
Okay, now I am confused.
These are the factory recommended spark plugs found in both my 1987 Owners Manual and 1987 Factory Repair Manual (this should be the same for your 1985):
Denso: W16EXR-U
NGK: BPR5EY
The Denso spark plug is what you will find sold at the dealer to Toyota's specifications.
The NGK BPR5EY spark plugs should also be just fine, as recommended by Toyota. The BPR5EY spark plug is part of NGK's V-Power line, per NGK's catalog:
