Crankshaft Position Sensor

[FJ4013]

You have to figure out why it is not turning over fast when hot. Is it lack of voltage or is the starter bad. I guess it is possible that the starter has an issue where it gets hot shorts out and you lose electrical power. When it quits, do other electrical things work? headlights, wipers, heater fan, etc. Is the starter hot as crap when it quits? Check electrical connections at starter, power ground and the little spade connector.

Other possible issue is the engine gets hot and somethings binds. But, if it was fuel or ignition the motor should still turn over just fine. Need to find out why it doesnt turn over when hot.

Honestly, everything under the hood is very hot when it quits. All electrical components still continue to work. Headlights, wipers, fan, etc. That was one of the first things I checked when it would die. I will look at starter threads. Any recommendations on a particular starter? I read sometime back people were going to gear reduction units or 60 series starters. Any insight?

 

[Pete]

Sorry for the length of my reply:

This is a long shot but since you've tried about everything with electrical/ignition and fuel delivery (tank, pump, in-line filters), I thought sharing my experience might help. Many years ago I had a problem with my '77 which would start fine and run for only about 5 seconds or so and then die. It would restart, run for a few seconds and die. I posted on the old Land Cruiser Mailing List (not sure Mud was in existence then) under the subject 2 seconds and die! I got all kinds of suggestions like you have and tried most all of the stuff that you have, when I decided to tear into the stock, Aisin carb. Before the 2 seconds and die problem started I had taken the top off the carb I think to adjust the float level but I really don't remember for sure now that it was 25 years or so ago. When I removed the top, I tore the gasket a little and anxious to get things going again and not wanting to wait on a new gasket, I used a very little bit of silicone gasket sealant on the old gasket. Now when I removed the carb as a last resort to fix the 2 seconds and die problem, what do you think I found in the float bowl when I started disassembly? Right, a couple of very small flakes of silicone, roughly 1/8" across, partially covering the jets! When the engine would first start, there was enough fuel that had seeped past the silicone "plug" but after a few seconds, the plug was sucked over the jet and no fuel was getting to the engine. Cleaned the bowl out, installed a NEW gasket, and bingo!

Not suggesting you have anything like I had but I just wanted to illustrate how something as small as a few silicone flakes in the wrong place can cause so much aggravation! Maybe the "beer bottle test" could help diagnose your problem. have a bottle of fuel handy and start her up and let her run until she starts to die. Trickle a little fuel down the carb throat and and see if she keeps running. If she does, you've got a fuel delivery problem. You've already checked your tank, pump, and in-line filter but you know there's a little thimble like screen right at the inlet to the carb. I'd check and clean that.

Good luck.
Pete

 

[S4Cruiser]

Honestly, everything under the hood is very hot when it quits. All electrical components still continue to work. Headlights, wipers, fan, etc. That was one of the first things I checked when it would die. I will look at starter threads. Any recommendations on a particular starter? I read sometime back people were going to gear reduction units or 60 series starters. Any insight?

Like the one I mentioned? Yes, if you are replacing then purchase a 60 series gear reduction starter from your local dealer. It will be refurbished...essentially new.

 

[S4Cruiser]

Not a landcruiser but similar issue as you. Sounds like a serviced / new starter fixed the issue.

Car stalls and then does not crank-start -Help - Team-BHP

I am confused though as to if/how a bad starter would cause the truck to cutoff?

 

[FJ4013]

Not a landcruiser but similar issue as you. Sounds like a serviced / new starter fixed the issue.

Car stalls and then does not crank-start -Help - Team-BHP

I am confused though as to if/how a bad starter would cause the truck to cutoff?

Here is what I read about heat soak and starter issues: https://www.knowyourparts.com/techn...ng/starter-will-not-crank-when-hot-heat-soak/

 

[emac]

That may explain why a hot starter will not fire, BUT why is the motor quitting when it gets hot. You dont need a starter to run. Here is a PDF of the wiring. Notice the + battery goes straight to the starter. That is where the starter solenoid gets power. Notice the other small wire going to the coil. Check that connection. Maybe the post is broken on the solenoid.


http://www.globalsoftware-inc.com/c...cs/FJ40/1977FJ40/1977_Toyota_LC_FJ40_FJ55.pdf

 

[FJ4013]

That may explain why a hot starter will not fire, BUT why is the motor quitting when it gets hot. You dont need a starter to run. Here is a PDF of the wiring. Notice the + battery goes straight to the starter. That is where the starter solenoid gets power. Notice the other small wire going to the coil. Check that connection. Maybe the post is broken on the solenoid.


http://www.globalsoftware-inc.com/c...cs/FJ40/1977FJ40/1977_Toyota_LC_FJ40_FJ55.pdf

That wiring diagram helped. I totally missed that in the manual. I took some pictures of the starter. All connections "seem" fine but the black wire connecting to the solenoid is really difficult to actually see so I got as close as I could with my camera to take a picture and it looks like the black wire is slightly melted at the connection point and the internal wires are corroded slightly. Would this be the culprit?

Starter 1

• FJ4013
• Sep 5, 2018

Starter Wire

• FJ4013
• Sep 5, 2018
• 1

Starter Wire Close Up

• FJ4013
• Sep 5, 2018

 

[emac]

Pretty sure that is the ground wire circled in red. Follow it to the frame and make sure it is clean and tight. What about the small wire and the one under the boot?

 

[FJ4013]

Pretty sure that is the ground wire circled in red. Follow it to the frame and make sure it is clean and tight. What about the small wire and the one under the boot?

I tried following those but it's impossible unless I cut open the wrapper the PO used to consolidate wiring. They go into a junction which is wrapped as well and it splits off into 2 different directions and I cannot follow any wires. I have no idea where they lead to. I followed the diagram but again without being able to see the the wires I have no idea of where they lead.

 

[emac]

Pretty sure the ground is on the passenger frame rail make sure it is tight and clean it will be the same size wire as on the starter. Pull back the rubber boot on the starter and check that wire, it is hot so dont ground it or it will spark. Did you check the small wire on the starter?

 

[Travis 76]

The starter solenoid should have 2 small wires coming out of it. 1 goes to the ignition switch, the other goes to the igniter or the coil. The wrong solenoid will cause problems. My friend had a 78 FJ40 he replaced the starter with a non Toyota part it had a typical 1 wire solenoid. His cruiser would not run. We finally replaced the solenoid with a 2 wire one and the truck started up and ran great.

 

[Slow Poke]

This must be extremely frustrating. I'm wondering if your engine isn't overheating. I know the gauge says different but it would explain why you cant turn it over very fast after it quits and why it seems "everything is very hot under the hood". Have you checked your coolant? Do you have a laser thermometer you can use to check the engine temp? Hope you figure it out soon.
Slow Poke

 

[456z]

Ive been following your dilemma and I am thinking along the same line as slow poke. Do you have a hand crank that you can use to see how hard it turns over when the starter won't turn it? This would tell you immediately if your motor is binding up.

 

[emac]

I thought about that as well, that certainly would be a worse case scenario and possible. He said the motor runs great, I would assume if it gets hot enough to overheat or lock up (repeatedly) it would be knocking, blowing steam, or otherwise trying to tell you I am in bad shape!

 

[FJ4013]

...

 

[FJ4013]

This must be extremely frustrating. I'm wondering if your engine isn't overheating. I know the gauge says different but it would explain why you cant turn it over very fast after it quits and why it seems "everything is very hot under the hood". Have you checked your coolant? Do you have a laser thermometer you can use to check the engine temp? Hope you figure it out soon.
Slow Poke

Definitely not an overheating issue. About 9 months ago I replaced the 40 yr old radiator with a brand new OEM radiator and a new OEM thermostat. Runs cool as it should now. The temp gauge definitely works and registers accurately. I've checked my engine multiple times with my therm gun to make sure temps are where they should be. Top of the radiator and the bottom of the radiator. Engine block, header, etc. All in the expected temperature ranges.

The engine does run great. Burns absolutely zero oil. Engine has never knocked once and it absolutely hums at 40 mph. I don't know if this will mean anything but the majority of the time the engine shut off issue occurs is when I am shifting into a higher gear. Typically from 3rd to 4th. It's shut off at other times but this is one nuance I have noticed. Maybe it's nothing more than coincidence so take it for what it is worth.

I need to correct something I said earlier. When the engine shuts off and I go to turn it over I made it sound like it chugs and sounds labored. It doesn't but I realize my post made it seem like it did. It does sound a little sluggish but not labored. It just tries to turn over but won't. But once it cools after 10-15 minutes it will start right up on the first turn. Sorry for the confusion.

I'm going to drive it in the next couple of days until the issue occurs and I will try to record a video of the sound it makes when I go to turn it over. Not sure if that will help but I'm sure more experienced ears will pick up something I am missing.

 

[FJ40newmechanic]

Sounds electrical to me. That is the only thing that explains why the starter is so weak after it shuts down. As the engine heats up, maybe the engine ground connection is becoming loose. That would explain the bad starter performance post shutdown, and possibly the shutdown due to a poor electrical circuit with the ignition. If your ground resistance is increasing due to a bad connection you circuit through the Dissy would be impacted. Your lights, and other electrical features would more than likely still work since their ground path back to the battery is different but everything that goes through the ground wire from the engine to the frame would be affected which would be the starter circuit on a restart when warm, and the ignition. Also explains why it works well when cold or after cooling down. The only other explanation is that something is binding mechanically due to thermal expansion but I would guess you would have to get the engine really hot for that to happen and major damage would ensue.

On a restart after a hot shutdown do you depress the clutch when starting or just have it in neutral? Might seam like a silly question, and I'm not trying to be a jerk, but just trying to rule things out.

How consistent is the time after start to shutdown? Is it always the same time regardless of how you are driving the FJ? If it just idles does it shut down the same time after a start vs, driving it?

How does it shutdown after running? Does the engine sound strained, loose power, then stall in gear? Does it just cut off like you turned the ignition off? Any warning? Can you describe the shutdown symptoms?

 

[FJ4013]

Sounds electrical to me. That is the only thing that explains why the starter is so weak after it shuts down. As the engine heats up, maybe the engine ground connection is becoming loose. That would explain the bad starter performance post shutdown, and possibly the shutdown due to a poor electrical circuit with the ignition. If your ground resistance is increasing due to a bad connection you circuit through the Dissy would be impacted. Your lights, and other electrical features would more than likely still work since their ground path back to the battery is different but everything that goes through the ground wire from the engine to the frame would be affected which would be the starter circuit on a restart when warm, and the ignition. Also explains why it works well when cold or after cooling down. The only other explanation is that something is binding mechanically due to thermal expansion but I would guess you would have to get the engine really hot for that to happen and major damage would ensue.

On a restart after a hot shutdown do you depress the clutch when starting or just have it in neutral? Might seam like a silly question, and I'm not trying to be a jerk, but just trying to rule things out.

How consistent is the time after start to shutdown? Is it always the same time regardless of how you are driving the FJ? If it just idles does it shut down the same time after a start vs, driving it?

How does it shutdown after running? Does the engine sound strained, loose power, then stall in gear? Does it just cut off like you turned the ignition off? Any warning? Can you describe the shutdown symptoms?

On restart after a hot shutdown I leave it in neutral. Oddly, the time after shut down to when it would restart changed once I replaced the old coil. When I was running the OEM 40 yr old coil the time to restart would take 20 minutes. Since I replaced the coil that time is now down to 10 ish minutes. You asked about consistency after start to shutdown and that varies based on the ambient air temperature. In summer months usually around 30 minutes of driving around town. Anytime I sit and idle at a light for a period of time I can feel the heat from the engine seeping through that firewall and I can't wait to get moving to get some air flow going. During the winter months when the air temperature is in the 70s and low humidity I can drive it nearly all day before it occurs. Sometimes during the winter months on cool days (60s) it will never shut down.

The way it shuts down after running is it simply begins to sputter and then dies completely. Sputters as if it is not getting enough gas and then shuts off. It will sputter 2-3 times before shut off. You can hear the engine trying to keep power but after 2-3 sputters it shuts down.

 

[FJ40newmechanic]

Could the sputtering be due to cylinders not firing due to intermittent ignition? Again, it sounds electrical in nature. If it was binding, it would be like it was slowing down to stall due to excessive load. Sputtering sounds like you are getting intermittent ignition. You say you know you have good spark after a shutdown, so may I ask how quickly you have checked it after a shutdown? Do you wait until it cools to check for spark or you know you have good spark as soon as it shuts down? I wonder if your condenser (capacitor) in the Dissy is acting up due to the heat but you replaced the entire Dissy with a new one correct? Does your coil have an internal or external ballast resistor? Have you ever measured its impedance when the engine is cold vs after a shutdown? Where is the ignition coil and ballast resistor mounted? If your ballast resistor is external to the coil how does the wiring look and is the resistor cracked or damaged in any visual way?

 

[FJ4013]

Could the sputtering be due to cylinders not firing due to intermittent ignition? Again, it sounds electrical in nature. If it was binding, it would be like it was slowing down to stall due to excessive load. Sputtering sounds like you are getting intermittent ignition. You say you know you have good spark after a shutdown, so may I ask how quickly you have checked it after a shutdown? Do you wait until it cools to check for spark or you know you have good spark as soon as it shuts down? I wonder if your condenser (capacitor) in the Dissy is acting up due to the heat but you replaced the entire Dissy with a new one correct? Does your coil have an internal or external ballast resistor? Have you ever measured its impedance when the engine is cold vs after a shutdown? Where is the ignition coil and ballast resistor mounted?

Checked for spark right when it happens and toast my fingers in the process but whatever. Also the dizzy is a new non-US dizzy (OEM) with the electronic ignition upgrade (Pertronix). I've run 2 brand new coils. The first was a new OEM coil and the second is a Pertronix Flame Thrower coil. It is internally ballasted and the correct Ohms. Mounted right where the OEM coil was mounted next to the battery. Never measured impedance.

Regarding the cylinders firing I sure hope not. I paid a shop to hone the cylinder walls and replace the pistons rings due to the PO using the wrong ring sizes which was burning oil. They checked everything and they are an FJ40 shop so I trust them. But that is functionality past my knowledge level.