95 FZJ80- Rough idle only when the AC is on. Otherwise, low idle at 600 rpm. Where should I begin? (1 Viewer)

[Jhnpv]

Morning everyone,

I have a low idle at 600 rpm, but when the AC is on, I hear a click from the engine bay, and the car idles at about 900rpm. About two minutes later, another click (which sounds like an "off" click), comes from the engine, and the car nearly stalls at 200 rpm until it rises to 600rpm. This cycle happens every 5 minutes ONLY when I am parked. Where should I look?


High Idle


Low Idle

 

[BILT4ME]

Well, that's normal cycling of an engine with the AC on. The engine idles up when the AC kicks on to help drive the compressor. When it shuts off because parameters have been met, it shuts off and idle drops back down again. Every vehicle does this.

The 200 RPM is a bit low. When was the last time the engine had a complete tune-up?
How many miles are on it?
Who did the last AC charge?

 

[Jhnpv]

Well, that's normal cycling of an engine with the AC on. The engine idles up when the AC kicks on to help drive the compressor. When it shuts off because parameters have been met, it shuts off and idle drops back down again. Every vehicle does this.

The 200 RPM is a bit low. When was the last time the engine had a complete tune-up?
How many miles are on it?
Who did the last AC charge?

Not sure when it had a complete tune-up as I bought this 6 months ago. 73,000 miles. Unsure of AC charge.

 

[BILT4ME]

Not sure when it had a complete tune-up as I bought this 6 months ago. 73,000 miles. Unsure of AC charge.

Is the Check Engine Light illuminated all the time?

If not, when you get ready to start the truck, you turn the key to "run", just before you start it......Is there a "check engine" light on the lower left side of the dash that is illuminated? It should come on at this time to be a light bulb check. It may or may not shut off after it starts. Please advise if it does.

 

[Jhnpv]

Is the Check Engine Light illuminated all the time?

If not, when you get ready to start the truck, you turn the key to "run", just before you start it......Is there a "check engine" light on the lower left side of the dash that is illuminated? It should come on at this time to be a light bulb check. It may or may not shut off after it starts. Please advise if it does.

Check engine light only comes on when I leave it in run, other wise, it goes away as soon as the engine starts.

 

[BILT4ME]

Check engine light only comes on when I leave it in run, other wise, it goes away as soon as the engine starts.

Good. That tells you the light is working and there are no active "emergency" codes. There may be codes, but they are minimal. Any O'Reilly's or Autozone can check your codes for free. If so, that may tell you if there is something going on.

What is your "mechanic" level?

1) I know nothing. I pay someone else to do everything
2) I kinda know some stuff and I might change my own oil.
3) I want to learn and I'm not afraid to dig in.
4) I regularly do engine work, body work, and regular maintenance.
5) Give it to me, I wanna tear it apart and put it back together!

This make a difference on how we further respond to you.

 

[Jhnpv]

Good. That tells you the light is working and there are no active "emergency" codes. There may be codes, but they are minimal. Any O'Reilly's or Autozone can check your codes for free. If so, that may tell you if there is something going on.

What is your "mechanic" level?

1) I know nothing. I pay someone else to do everything
2) I kinda know some stuff and I might change my own oil.
3) I want to learn and I'm not afraid to dig in.
4) I regularly do engine work, body work, and regular maintenance.
5) Give it to me, I wanna tear it apart and put it back together!

This make a difference on how we further respond to you.

Recently started getting into cars when I bought the cruiser 6 months ago. I would say I am somewhere between a 2 and a 3.

 

[BILT4ME]

Recently started getting into cars when I bought the cruiser 6 months ago. I would say I am somewhere between a 2 and a 3.

OK.

Under the hood, on PASSENGER side (left side) is the fuse block. (Edited due to being RHD)

Open it and pull the fuse marked "EFI". It is in the lower right of the box as you see it in the diagram below.

Pull it out and keep it out for 5 minutes.

This will clear all stored codes and will force the engine to "relearn" all of it's stored parameters.

Reinstall the fuse, then do the following:

1) Turn the key to the "run" position, leave it for 10 seconds, then turn back to off.
2) repeat step 1 three times.
3) Start the truck. You may find that as soon as it starts, it revs way up, then back down, then back up and it may do this 4-5 times, then it will settle down. Doing the key sequence above helps alleviate some of that.

You have now cleared all stored codes and your truck will start to learn your driving style, throttle position, acceleration and braking habits and will adjust fuel consumption accordingly.

This helps you "start fresh" to see if there are thins you are unaware of.

As a suggestion, when you do start replacing parts and doing your own work, use Toyota parts when possible. This is not because we're purists, it's because we have seen where problems persist. There are some things you can get by with, but you'll figure these out.

Read a LOT on this forum, as every question you have about your truck has been answered at least once here. Use the search function. Ask when you don't know. Diagnose BEFORE replacement. Don't just throw the parts cannon at it. That's REALLY expensive.

 

[Jhnpv]

OK.

Under the hood, on driver's side (left side) is the fuse block.

Open it and pull the fuse marked "EFI". It is in the lower right of the box as you see it in the diagram below.

Pull it out and keep it out for 5 minutes.

This will clear all stored codes and will force the engine to "relearn" all of it's stored parameters.

Reinstall the fuse, then do the following:

1) Turn the key to the "run" position, leave it for 10 seconds, then turn back to off.
2) repeat step 1 three times.
3) Start the truck. You may find that as soon as it starts, it revs way up, then back down, then back up and it may do this 4-5 times, then it will settle down. Doing the key sequence above helps alleviate some of that.

You have now cleared all stored codes and your truck will start to learn your driving style, throttle position, acceleration and braking habits and will adjust fuel consumption accordingly.

This helps you "start fresh" to see if there are thins you are unaware of.

As a suggestion, when you do start replacing parts and doing your own work, use Toyota parts when possible. This is not because we're purists, it's because we have seen where problems persist. There are some things you can get by with, but you'll figure these out.

Read a LOT on this forum, as every question you have about your truck has been answered at least once here. Use the search function. Ask when you don't know. Diagnose BEFORE replacement. Don't just throw the parts cannon at it. That's REALLY expensive.

View attachment 2594884

I really appreciate it. This is gonna be the first thing I do this weekend. Thanks for the help!

 

[tacocat]

700 RPM is standard idle for an FZJ80 according to the service manuals. What’s up with the cruise control stalk on this truck?

 

[BILT4ME]

Is this a RHD truck?

How about full pics and specs?

VERY different from USA spec trucks.

 

[Jhnpv]

700 RPM is standard idle for an FZJ80 according to the service manuals. What’s up with the cruise control stalk on this truck?

Pretty much how I got it. Imported this RHD cruiser from Australia.

 

[Jhnpv]

Is this a RHD truck?

How about full pics and specs?

VERY different from USA spec trucks.

It is indeed. 1995 Land Cruiser GXL.

Just realized I made the picture way too large, but oh well. This is the only real good picture I have of it right now, but I can certainly take a picture of anything you would like to see.

Also, are there any specs you'd like to know specifically?

 

[tacocat]

It is indeed. 1995 Land Cruiser GXL.

View attachment 2595321
Just realized I made the picture way too large, but oh well. This is the only real good picture I have of it right now, but I can certainly take a picture of anything you would like to see.

Also, are there any specs you'd like to know specifically?

Huh. I didn’t know the RHDs flipped the cruise control stalk to the other side and use a completely different unit.

I bet there is a vacuum leak from the de smog.

 

[BILT4ME]

It is indeed. 1995 Land Cruiser GXL.

View attachment 2595321
Just realized I made the picture way too large, but oh well. This is the only real good picture I have of it right now, but I can certainly take a picture of anything you would like to see.

Also, are there any specs you'd like to know specifically?

Damn!

That's a beautiful truck!

 

[Jhnpv]

Damn!

That's a beautiful truck!

Greatly appreciate it. Its a work in progress. Still pretty stock, but I plan on working on that.

 

[jonheld]

700 RPM is standard idle for an FZJ80 according to the service manuals. What’s up with the cruise control stalk on this truck?

FSM states 650 +/- 50, so I wouldn't fret too much about 600.

 

[jonheld]

This will clear all stored codes and will force the engine to "relearn" all of it's stored parameters.

Reinstall the fuse, then do the following:

1) Turn the key to the "run" position, leave it for 10 seconds, then turn back to off.
2) repeat step 1 three times.

Other than removing the 15 amp EFI fuse, nothing else is needed.
Not sure anything is gained by switching the ignition on and off 3 times other than exercising the ignition cylinder.
Typically the idle speed will increase for the first few drive cycles, but I have never had one cycle up and down after a reboot.

 

[BILT4ME]

Other than removing the 15 amp EFI fuse, nothing else is needed.
Not sure anything is gained by switching the ignition on and off 3 times other than exercising the ignition cylinder.
Typically the idle speed will increase for the first few drive cycles, but I have never had one cycle up and down after a reboot.

I know it doesn't state that.

I did this just for the heck of it one time because I've had other vehicles state to do that after a battery swap.

When I did it on my LC, it started right up, did not hunt for RPM, and was smooth from the get-go.

It kinda surprised me, so now I do it every time. It takes out some of the anxiety for me of the RPM up and down and worrying it won't settle.

 

[jonheld]

I know it doesn't state that.

I did this just for the heck of it one time because I've had other vehicles state to do that after a battery swap.

When I did it on my LC, it started right up, did not hunt for RPM, and was smooth from the get-go.

It kinda surprised me, so now I do it every time. It takes out some of the anxiety for me of the RPM up and down and worrying it won't settle.

Hard to say then. I've never had one hunt for RPM before, 3FE of 1FZ-FE. Just put the fuse back in or reinstall the battery (depending on what I'm doing that day), start and drive away. Never an issue.
I will add that I typically remove the EFI fuse before starting any work under the hood, so it's out for quite some time. I look at it like simply rebooting my laptop or phone. It needs to get done every once in a while.