FJ60 carb cooling fan (1 Viewer)

[jasheehan]

I have a FJ60 that is a pain to hot start? I received a post saying that it is likely the carb cooling fan. I checked it out and the "ground" wire is burnt through. When I reattach this wire to a ground, the fan stays on and never shuts off. Can anyone help me out on how I go about fixing this? Do I need a whole new harness, or is there a quick fix?

Also, does anyone know what the sensor is for that is located inside the catalytic converter? I took the CC off to check and see if it was blocked, and I saw this sensor? I'm thinking about removing the CC altogether since this vehicle doesn't go through emissions, but if I do this, what is the significance of the sensor?

Thanks.

Jeff

 

[2mbb]

The carb fan wire shouldn't be connect to a ground but to a temperature switch that is then grounded. The switch is mounted on a piece of sheet metal near the exhaust pipe under the exhaust manifold.

The thermosensor in the catalytic convertor is used to measure when the cat gets too hot. If the cat gets too hot, then the thermosensor opens the air bypass valve connected to the smog pump, diverting air away from the cat.

 

[mrsvle]

This is the beast, this is where it lives.

First picture: the carb cooling fan sensor
Second picture: Where it lives (red circle) on bracket attached to EGR valve, positioned under the intake/exhaust manifold.

The wire to the carb cooling fan sensor can often burn through. You simply need to reattach it. You may need to splice in some new primary wire. Also, you can clean the carb cooling fan sensor by blasting it with some WD-40 and working it around.

 

[AATLAS1X]

The carb fan wire shouldn't be connect to a ground but to a temperature switch that is then grounded. The switch is mounted on a piece of sheet metal near the exhaust pipe under the exhaust manifold.

The thermosensor in the catalytic convertor is used to measure when the cat gets too hot. If the cat gets too hot, then the thermosensor opens the air bypass valve connected to the smog pump, diverting air away from the cat.

How does it divert air away from the cat?

 

[AATLAS1X]

I have a FJ60 that is a pain to hot start? I received a post saying that it is likely the carb cooling fan. I checked it out and the "ground" wire is burnt through. When I reattach this wire to a ground, the fan stays on and never shuts off. Can anyone help me out on how I go about fixing this? Do I need a whole new harness, or is there a quick fix?

Also, does anyone know what the sensor is for that is located inside the catalytic converter? I took the CC off to check and see if it was blocked, and I saw this sensor? I'm thinking about removing the CC altogether since this vehicle doesn't go through emissions, but if I do this, what is the significance of the sensor?

Thanks.

Jeff

How many miles? You may have a leaking injector and when this happens it soaks into the carbon and turn into a non flamable solvent and causes hard hot starts.

Buy new at $300 a pop or have a local DR. Injector rebuild them all at $18 each. You will have the best running rig after.

EDIT.

LOL, never mind you have have a 60................I was thinking of a 62 that was a customer of mine....

 

[jasheehan]

First picture: the carb cooling fan sensor
Second picture: Where it lives (red circle) on bracket attached to EGR valve, positioned under the intake/exhaust manifold.

The wire to the carb cooling fan sensor can often burn through. You simply need to reattach it. You may need to splice in some new primary wire. Also, you can clean the carb cooling fan sensor by blasting it with some WD-40 and working it around.

Thanks so much for your help. I think I can fix this. I will need to get some more wire and splice it together. I did notice that there is a wire harness that comes out of the carb coolign fan, and then this wire that burnt off comes out of that harness and goes into a plastic sleeve or connector, and then it burnt off after that. What is this connector for?

Again, thank you very much. I got this Cruiser over Christmas, so I'm just getting used to it.

Jeff

 

[FJ60Cam]

"When I reattach this wire to a ground, the fan stays on and never shuts off"


The fan does have a built in timer. I grounded mine instead of reattaching to the sensor, and it shuts off after 20-30 minutes. It starts MUCH easier now.

 

[2mbb]

How does it divert air away from the cat?

Under normal operation, the air bypass valve is open and air from the smog pump is pumped into the exhaust manifold and/or exhaust pipe. The thermosensor is a temperature switch. When the thermosensor gets hot it goes from open circuit (high resistance) to closed circuit (low resistance). When the thermosensor closes, the emissions comptuer sends a signal to the air bypass valve to close. This diverts the air coming from the smog pump back into the air cleaner and stops the air flow into the exhaust.

The chemical reaction that takes place in the catalytic converter uses oxygen (from air) to oxidize the bad emissions (HC, NO, CO) to less harmful ones (H2O, CO2, etc.) The oxidiation reaction releases heat. With out air, there is no reaction and therefore not heat is released and the cat cools off. The thermosensor essentially prevents the catalytic converter from burning up.

 

[nuclearlemon]

i run mine off a toggle switch.

 

[brian]

so if i just ground the sending wire the fan will:
1. run all the time whenever the key is on?
2. run after the key is turned off, then shut off after the timer times out after 20-30 minutes?

if that is the case i'll ground my sending wire.




**edit**
i grounded the sending wire about 20 minutes ago.
1. it runs only after the key is turned off.
2. it runs only about 15-20 minutes.

on a hot start, it fired right up, which is a huge change.

 

[Southbound]

Just used the knowledge from this thread to reatttach the wire from the carb fan to the temp sensor. Sadly, nothing happens with the engine on or off, hot or cold. The carb fan works fine if I just ground it. Should I assume the sensor is shot? The sensor is a bit hard to get to but shouldn't be hard to replace.

 

[60wag]

Just used the knowledge from this thread to reatttach the wire from the carb fan to the temp sensor. Sadly, nothing happens with the engine on or off, hot or cold. The carb fan works fine if I just ground it. Should I assume the sensor is shot? The sensor is a bit hard to get to but shouldn't be hard to replace.

You might try leaving it connected and wait a week. Its got to be pretty hot for the sensor to switch on. My fan runs frequently. I know some whose fan hardly runs at all. Maybe its due to variation in the sensors or maybe my exhaust manifold runs pretty hotter than some.

 

[mrsvle]

The sensor is spring loaded and can get all crudded up. Remove the sensor, hit it with some WD-40 and/or Lime-Away, work it in and out to get rid of the grit that can get trapped inside. Then replace. It should work fine.

HTH

Matt

 

[notagp_afj55]

My fan runs after every time i drive it for about 15-20 regardless of the
outside temp. of course it's summer and so i don expect it to run when
the temps get dow in the 30's and 40's. The last post i posted some
said if it runs usually after every drive then it is doing its job


-Jim

 

[Southbound]

Good ideas on trying to save the current sensor. That's the good thing about old school mechanical devices (vs. computers) - often times a little cleaning or bending will set things right. I'll give it a shot.

 

[Cruzerman]

Like it's been said, if you can't get the sensor to work you can just ground the wire. Only downside is that it will run the fan every time you turn off the motor, not just when it's hot. No harm done.

 

[soggy60]

1. The sensor is a therm-responding resistor, you can't get inside to clean.

2. Remove wire from harness carefully, there's a plug....

3. Remove sensor; clean threads
Unscrew & re-screw one of the bolts above sensor on bracket

4. You can 'test sensor'- need ohm meter (or friend with one)
'cold' (room temp) resistance many thousand ohm
very hot (boiling water - tease with lighter) few thousand ohm, maybe less.

( the cleaning, bolt turning...step 3,,,is to reduce unwanted resistance)

HTH

Pete

 

[Southbound]

Well, I took out the sensor, tested it, reinstalled it and now it's working like a charm. Amazing how often that happens. It probably wasn't connecting properly with the sheet metal to conduct electricity and just taking it out and cleaning it did the job.

Thanks!

 

[Southbound]

Sweet, now I know what the fender vents are for - they are the intakes for the carb fan. Very cool.

 

[vanyoska]

82 - 83 FJ60 Carb Cooling Fan (do they have them?)

I'm looking at an '82 and '83 FJ60 and may buy one of them.
The person with the 83 said there's not supposed to be a fan that runs after the motor shuts off. The one with the 82 said it runs on a hot day. Is this how they are both supposed to run. If not, what is wrong? Thanks
I don't want to make a mistake and buy a bad LC as I can't fix it myself and have limited resources. I'd welcome anywone with any advice about this situation and the specs on the cars (as I'd hate to brake down on a 2500 mile trip).
Thanks
Vanyoska
ratmoppett@verizon.net