1988 FJ62 MAF Suggestions (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Apr 27, 2021
Threads
4
Messages
24
Location
Anaheim
Hey guys I recently bought an FJ62 and absolutely love it, only issue is starting and rough idle issues. Took it into a mechanic before I bought it and they said it looked good. Took it to another places when issues came up and he suggested the MAF was bad due to running rich. I saw other people with similar issue here but no body has mentioned what they went with in the end. An OEM MAF is really hard to find, I saw that Duralast makes one and also Cardone. Another forum as saying the Cardone is an OE reman part although I haven't found anyone using one for this truck. Any input would be great trying not to go crazy, since I am new to all of this I was going to join the TLCA since they have a chapter in Orange county where I am at. Looking forward to learning from everyone and talking to everyone.
 
Do you have a copy of the factory service manual? If not, there are free downloadable PDFs readily available. Test the AFM according to the troubleshooting section of the manual to really decide if the AFM is bad. If it is, I have seen some people swap on a Camry AFM as well with success. Maybe you can find a good used version of that to swap on ? Hopefully someone that has swapped on a Duralast unit cam chime in as well.
 
Do you have a copy of the factory service manual? If not, there are free downloadable PDFs readily available. Test the AFM according to the troubleshooting section of the manual to really decide if the AFM is bad. If it is, I have seen some people swap on a Camry AFM as well with success. Maybe you can find a good used version of that to swap on ? Hopefully someone that has swapped on a Duralast unit cam chime in as well.
I do not have the service manual, I saw a couple links on other threads but the link seemed dead. So if you have a suggestion on a source that would be great.

The camry ones looked like a solid option just haven't heard of them being used and or if they are much different. The guy i took it to was a toyota technician that has done work to other 60 series so I don't think hes BSing but anything i can do on my own I'm willing to try. The Cardone and Duralast seemed like the best options besides the camry. Hopefully someone with experience with those has some input.
 
No MAF (Mass Air Flow) on a FJ62 there is an AFM (Air Flow Meter). Use the manual to trouble shoot. If it is running rich I would look at the O2 sensors first. Maybe pull the plugs to verify rich condition. Unless you have a wideband sensor or a tail pipe sniffer.
Dyno
 
I do not have the service manual, I saw a couple links on other threads but the link seemed dead. So if you have a suggestion on a source that would be great.

The camry ones looked like a solid option just haven't heard of them being used and or if they are much different. The guy i took it to was a toyota technician that has done work to other 60 series so I don't think hes BSing but anything i can do on my own I'm willing to try. The Cardone and Duralast seemed like the best options besides the camry. Hopefully someone with experience with those has some input.
You should be able to get some FSM here: CruiserManuals.com - https://www.cruisermanuals.com/
Not insinuating your tech is BS'ing :). Just some times it seems mechanics will throw a part into suspicion when it may be worth the time to work through it with the FSM first before making the call.
There are not many sensors on the 3FE but the ones that are there are important to check and can all cause the symptoms you are describing. It would be good to check your throttle position sensory as well.
 
Awesome thank you for the manuals thats going to be super helpful. And yes it is an AFM not MAF thank you for that correction, I wasn't super positive. I have already changed the spark plugs, spark plug wires, distributor cap, rotor, and fuel filter. So ill try and just go down the line next of what it could be, starting with the AFM since that controls the amount of fuel that gets put into the engine to my knowledge. Thanks for the help so far, definitely should have made an account here sooner.
 
starting with the AFM since that controls the amount of fuel that gets put into the engine to my knowledge

It is a multi input system. The O2 sensors, water temp sensors, IAC, AFM, as well as the speed sensor all control the amount of fuel. In addition it may me an injector problem. Don't chase parts, it can get very expensive very quickly. Download the manual and look in the trouble shooting section. Be meticulous with the testing procedures.
Dyno
 
There is no electronic speed sensor on a 62, so you can eliminate that from the equation (unless you're referring to engine speed indicated by the tach signal into the ECU). O2, water temp, and AFM are what the ECU will use to control the fuel mixture as accurately as it can. The IAC (idle air control) only controls the amount of air allowed into the throttle body via the idle air passageway.

Funny that should come up because recently my idle speed has gotten really inconsistent, so I'll need to dig into my FSM to troubleshoot that along with testing the IAC itself off the vehicle.
 
There is a VSS (not just a tac signal), it gets a signal from the speedo in the combo meter housing. It is pin 11 on the ECU.
Dyno
 

Attachments

  • VSS.pdf
    185 KB · Views: 72
There is a VSS (not just a tac signal), it gets a signal from the speedo in the combo meter housing. It is pin 11 on the ECU.
Dyno
I can say with 100% certainty that there is no VSS in the US spec FJ62. The only things connected to the speedo are the cable to drive it from the transfer case and a lead for the two light bulbs in it. I've had mine apart many times.

As far as the FJ80, I wouldn't be surprised if there's a VSS, but there absolutely isn't one from the factory in an FJ62.
 
This is NOT my experience. Engine trouble code 42 is no VSS signal. The 3FE in My 40 would throw this code until I put in a VSS.

The ECU receives a pulse with every rotation of the speedo. (I believe 4 pulses per revolution)
 
Last edited:
I can say with 100% certainty that there is no VSS in the US spec FJ62. The only things connected to the speedo are the cable to drive it from the transfer case and a lead for the two light bulbs in it. I've had mine apart many times.

As far as the FJ80, I wouldn't be surprised if there's a VSS, but there absolutely isn't one from the factory in an FJ62.
Yes there is.
 
There is a speed sensor into the ECU on the FJ62. Right in the FSM. The ECU may know the speed, but yes its not connected to the speedometer.

Edit: What they said :)
 
Speed sensor signal feeds from speedometer.
IMG_20210429_154614.jpg
 
Sweet! I dont remember that connector. Nice! :)
 
Speed sensor signal feeds from speedometer.
View attachment 2660422
Okay I can verify that connector is NOT there in my 88 and I still run the factory speedo. Perhaps later 62s then? If that's the case I just learned something new.

@RockDoc what years does that schematic cover?
 
Last edited:
1989... I'll look and see if I have any pics from the the '88 cluster I put in a FJ55..

Edit**
From an old pic, it looks like the speedo from my '88 poverty pack Canadian market 62 (Sept 87 build) has a 4 wire connector. Things are too tight under the dash to verify. We're getting pretty off topic here though...
 
Last edited:
Starting from the premise it is running rich at idle. Aside from a dribbling main injector, a dribbling cold start injector or faulty timer switch for it would cause a rough/rich idle after warm up, but maybe not noticeable at higher revs. TPS may be out of adjustment. Is it throwing any codes? The 88 FSM shows a VSS, but it would not have anything to do with idle. I attached a good write up on the TCCS system, note not all of the sensors described are used with the 3fe.

1620236232452.png
 

Attachments

  • TCCS__TOYOTA_COMPUTER_CONTROLLED_SYSTEM_.pdf
    14 MB · Views: 97
Starting from the premise it is running rich at idle. Aside from a dribbling main injector, a dribbling cold start injector or faulty timer switch for it would cause a rough/rich idle after warm up, but maybe not noticeable at higher revs. TPS may be out of adjustment. Is it throwing any codes? The 88 FSM shows a VSS, but it would not have anything to do with idle. I attached a good write up on the TCCS system, note not all of the sensors described are used with the 3fe.

View attachment 2666059
Talking with @RockDoc via PM about that and I made a discovery that piqued my interest too. I cant stand to not find out every possible detail about something that I was so completely unaware of that I was confident there was nothing there (at least not in the sense that I was originally arguing, but I still was sure there wasn't anything inside the speedometer either). I'm going to start a new thread on that so this doesn't get steered away, but I'm at work right now so will have to do it tonight.
 
Hey guys so little update with the 62, I ended up finding an OEM AFM from Cruiserparts.com based in Florida I believe. Installed it and after a few minutes it worked flawlessly, fixed my random RPM issues and fixed the issue of RPM dropping when I press on the gas. I have been driving it to and from work all week with no real issues. One thing I have noticed though is that it is slow to start will turn over a few times before firing up, will need to start trouble shooting that next. Was thinking it might be the starter assembly or ignition coil but I have no real idea. Then after that take care of some seals and other things like that, thanks for your guys help with the trouble shooting advice and the manuals.
 

Users who are viewing this thread

Back
Top Bottom