Correct speed sensor (VSS) info for 3FE swap (1 Viewer)

[tlc4x]

Well, I couldn't find the answer so I did a lot of digging and I now know how to do the CORRECT VSS for a 3FE (head or whole engine).

Some background: I am swapping a 1991 3FE into my 1973 FJ40 along with an h55F and split transfer. I want to install cruise control and A/C also. So, for the ECU and CC ECU from the 3FE to work correctly you need two VSS modules (no it will NOT if you don't have the VSS).

The VSS from an FJ80 and FJ62 is in the speedometer. It is a reed switch type so it is DC. It outputs 4 pulses per revolution of the speedometer cable. There is another VSS on the transmission where the speedometer cable attaches. This VSS is used for the cruise control. It is NOT a reed switch type. It requires 12V to activate it and then outputs 4 pulses per revolution. I don't know why there are 2 VSS units but there are.

The VSS that is in the speedometer housing is a spinning magnet that trips a reed switch. This is EXACTLY the same setup as an FJ40. However, there are two different types of FJ40 speedometers. One type outs out 6 pulses per revolution and the other outputs 4 pulses per revolution. Early speedometers do not have a VSS.

The 6 pulse per revolution VSS has a larger magnet assembly than the 4 pulse. Bottom line... you can use the FJ40 VSS for the conversion. You do not need an aftermarket VSS.

I just thout this would be very useful for those of us that have done, are doing or will do this conversion. As a side note, if you do a GM TBI conversion it might need a 6 pulse VSS (I am not sure on this). In that case, again the Toyota VSS can be used.

 

[tlc4x]

Cruise control VSS from an A440 transmission

Cruise control VSS separated

Cruise control VSS attached to H55F and split transfer case (I did not use the A440 gear)

 

[tlc4x]

6 pulse VSS

4 pulse VSS - notice the magnet is smaller (shiney gold thing).

 

[pappy]

Actually, this has been discussed before. Nice observation on the A440F VSS. Wish I knew that before.

3FE VSS


Also, I wrote this up awhile back. Don't know if it helps you or not, 3FE Conversion into 1969 FJ40. I need to work on it some more, so it's still a draft.

 

[mmw68]

Did you see my post about this? I just had one made not too long ago.

I ordered it from Speedometer Service Co., Milwaukee, WI,
414/463-6660. Thanks to Pappy for suggesting them. Two day service and they really knows there stuff. They split my fj40 cable, made a custom VSS, and rebuilt the lower half of the worn out speedo cable. $174.00

https://forum.ih8mud.com/60-series-wagons/187677-3fe-speed-sensor-5-speed.html

 

[tlc4x]

Did you see my post about this? I just had one made not too long ago.

I ordered it from Speedometer Service Co., Milwaukee, WI,
414/463-6660. Thanks to Pappy for suggesting them. Two day service and they really knows there stuff. They split my fj40 cable, made a custom VSS, and rebuilt the lower half of the worn out speedo cable. $174.00

https://forum.ih8mud.com/60-series-wagons/187677-3fe-speed-sensor-5-speed.html

Yep. I saw yours and Pappy's post. But no one uses the stock sensor. There is no reason to order a special sensor when it is already built into the FJ40 speedometer. I bought both my sensors for $100. If I felt lucky I could have gotten the instument cluster one (plus all the other instruments) for $75 or less off of ebay (it's hard to get someone to check how many pulses before you buy).

 

[tlc4x]

Actually, this has been discussed before. Nice observation on the A440F VSS. Wish I knew that before.

3FE VSS


Also, I wrote this up awhile back. Don't know if it helps you or not, 3FE Conversion into 1969 FJ40. I need to work on it some more, so it's still a draft.

Hi Jon,

I have extensively used your write up... VERY NICE! However, the VSS was one short point. The Autometer is not needed. The FJ40 VSS is the exact same one that is used in the FJ62 or FJ80. One other problem I have is some of the desmogging info I have seen. It seems like most people don't read the EWD and FSM when they make comments. I will post up a more complete guide to what I am doing but so far I have not needed a single aftermarket piece. No one discusses the cruise control, and that took the longest to figure out. As for the A/C, it is cryptic and not discussed about the third VSS that it uses. I was very grateful you wrote up your document as I definitely had to get the main wiring cowl, I am just going a bit further...

Just to clarify, I dismantled an FJ40 speedometer and an FJ80 to confirm all of this. I don't know about the one you guys bought. I would assume that it is a reed switch type, but if it is a hall effect type (or similar) it will be AC not DC. I don't know the long term effects on the ECU from this type of sensor. It could be that grounding one terminal makes it DC or you could have competition that is slowly degrading the input buffer on the ECU. But I am an Electrical Engineer so this is one area that I can talk about with certainty.

Chris

PS. If you don't mind, I can add to your write up to answer very specific questions I am answering.

 

[pappy]

Hi Jon,

The FJ40 VSS is the exact same one that is used in the FJ62 or FJ80. One other problem.

I wasn't aware that the FJ40 used a VSS. I didn't even look since I couldn't see why it was needed on an old carbed engine. Do you know which years had this? Unfortunately, I don't have my stock dash to take a part and look. Also, I'm not using an Autometer VSS, but I am using an Autometer speedometer, which is why I have the first VSS.

 

[mmw68]

Chris - great info, maybe I'll revise this in my FJ40. With all these 3FE-FJ40 swaps, maybe we should make this a stickie in the FAQ?

-Mark

 

[Trollhole]

Great info and just what I was looking for. There are actually two VSS on a 76 fj40 that I know of. One on the firewall and one on the speedo. But didn't know how many pulses or whether they would work with a TBI or 3fe setup. But we are getting closer.

Using these would be a heck of a lot easier and cleaner than running something from the back of the t-case.

 

[pappy]

But didn't know how many pulses or whether they would work with a TBI or 3fe setup. But we are getting closer.

I don't think the reed-switch type will work on the TBI. Can we get pics up of the FJ40 VSS? I'm intrigued. And I sure wish I knew the VSS on the A440F would work. I've had my hands on several FJ62s and it would have been nice to have harvested those. I guess we need to add the A440F VSS to the list of items to harvest for those doing the 3FE swap.

 

[pappy]

... it's hard to get someone to check how many pulses before you buy.

I traced the VSS signal from the ECU to the speedo when I did my research. On one of my harvest trips I grabbed an FJ62 speedo an did the continuity test on the VSS terminals. That was how I also came up with the 4-pulse reed switch conclusion.

This is bitchin stuff. Keep it coming.

 

[tlc4x]

I don't think the reed-switch type will work on the TBI. Can we get pics up of the FJ40 VSS? I'm intrigued. And I sure wish I knew the VSS on the A440F would work. I've had my hands on several FJ62s and it would have been nice to have harvested those. I guess we need to add the A440F VSS to the list of items to harvest for those doing the 3FE swap.

The VSS in th eFJ40 speedometer is shown in post 3. The round magnet trips the reed switch above it and the two terminal coming out the back of the instrument cluster short together. The two terminals are the ones behind the speedometer.

I do not know if the VSS from the transmission can be used for the ECU. I got it because it is used for the cruise control ECU. You can see from this page of the EWD that it outputs 1 pulse per 40cm (I think that's 4 pulses per revolution).

 

[tlc4x]

I traced the VSS signal from the ECU to the speedo when I did my research. On one of my harvest trips I grabbed an FJ62 speedo an did the continuity test on the VSS terminals. That was how I also came up with the 4-pulse reed switch conclusion.

This is bitchin stuff. Keep it coming.

This page from the repair manual states that the VSS in the combination meter is 4 pulses per revolution. The VSS (magnet and assembly) is very similar to the that of the FJ80 (and I guess FJ62). They are not interchageable though. I tried to swap it into my FJ40 speedometer but it is too short of a shaft and the reed switch is to the side, vs under the cable attachment point.

 

[FJ40Jim]

Great info and just what I was looking for. There are actually two VSS on a 76 fj40 that I know of. One on the firewall and one on the speedo.

The box on the firewall of 75-76 is only an odometer. It trips every ~50K miles and illuminates the red "EGR" warning lamp on the dash.

The VSS is in US FJ40 speedometers from ~1972-onwards. '69-71 models it is inline in the speedo cable, like 3FE. It's used to run the emissions control system as the vehicle coasts down.

HTH.

 

[tlc4x]

The box on the firewall of 75-76 is only an odometer. It trips every ~50K miles and illuminates the red "EGR" warning lamp on the dash.

The VSS is in US FJ40 speedometers from ~1972-onwards. '69-71 models it is inline in the speedo cable, like 3FE. It's used to run the emissions control system as the vehicle coasts down.

HTH.

Yeah, I thought it went to some sort of computer. I just didn't know what it did on those early trucks. Interesting about the one on the firewall. I saw it in the parts catalog but have never seen it in person.

It is interesting that the VSS units in the FJ40 are either 6 pulse or 4 pulse. Is ther a reason for that? When I went to SOR to test all their used speedometers, there was only one that was a 4 pulse. Everything else had the large 6 pulse magnet.

 

[tlc4x]

I don't think the reed-switch type will work on the TBI. Can we get pics up of the FJ40 VSS? I'm intrigued. And I sure wish I knew the VSS on the A440F would work. I've had my hands on several FJ62s and it would have been nice to have harvested those. I guess we need to add the A440F VSS to the list of items to harvest for those doing the 3FE swap.

Definitely harvest those VSS modules. Also ge the transmission harnes, cooling fan ECU, CC ECU and A/C ECU. You never know if you want to add it. But thos VSS modules go for $125 or so new.

 

[redrustbucket]

There are two different types of FJ40 speedometers. One type puts out 6 pulses per revolution and the other outputs 4 pulses per revolution.

The VSS is in US FJ40 speedometers from ~1972-onwards.

I'm guessing the VSS pulse changed with different years of the fj40. If so anyone know some pulse outputs for specific years of the 40. I have a '72 40 I'm dropping a 3fe into. I'm hoping that this year speedo has the correct pulse output of 4. Of course I will also stop being lazy and check it myself assuming I can figure out how.

 

[tlc4x]

I'm guessing the VSS pulse changed with different years of the fj40. If so anyone know some pulse outputs for specific years of the 40. I have a '72 40 I'm dropping a 3fe into. I'm hoping that this year speedo has the correct pulse output of 4. Of course I will also stop being lazy and check it myself assuming I can figure out how.

To check it:

1. Take out the gauge cluster
2. On the back, behind the speedometer, you will see two terminals (above the speedometer cable attachment)
3. Connect a multimeter to those terminals and set it to beep on continuity
4. Turn the cable (or the bearing is you remove the cable)
5. It will pulse 4 or 6 times per revolution

You can also just take the speedometer out and then you can see the round magnet assembly. If it is big it is probably 6 pulse. Small will be 4 pulse.

 

[redrustbucket]

I'll check it out. Thanks.