FZJ80 won't start when hot.... (1 Viewer)

[REDrum]

Help please!

Yes, I have searched and read up to see if other have had similar symptoms and have not found similar.

Symptoms:
In Northeast US, during warm months (May thru Oct) after long drives or on very hot days truck will not start after being run for more than 20 minutes. Turn key just a click. This is intermittent. Nov thru April very rarely an issue. Let truck sit for 60 minutes or more and it fires up. Clearly something thermal.

The work around has been to hot wire from + on battery to hot side of starter, then it starts right up. (I keep a long test lead in the truck just for this purpose, and have it down to less than 1 minute

Thoughts, ideas, exorcism recommendations all welcome.

In past year replaced:
Starter
Alternator
Battery

Only thing I have not replaced is neutral safety switch but from what I have read not likely the culprit, but happy to be convinced other wise.

 

[Can1979]

Check your fuel pump, when it becomes hot its not working anymore and check If you face this issue when your tank is fully loaded. If not , then it might be ur fuel pump. Cause the tank is fully filled it will help the pump to keep working properly and the fuel will remain colder.

 

[Can1979]

Cause WHEN the tank is *

 

[LC4LIFE]

What kind of starter? New OEM, used, Autozone, etc? I have seen starters behave that way.

 

[MoJ]

Have you tried a new fusible link set?

If you’re not already familiar with this guide:

Emergency Troubleshooting Procedures - FAQ Item (Recommend Keeping Copy in Truck)

For updates or revisions, please PM me, nuclerlemon or semlin The below is a troubleshooting guide if your in the boonies to help isolate a non starting vehicle problem. This is a compilation from forum members, specifically RavenTai, KliersLC, Landtank and Beaowulf. This will not catch each...

forum.ih8mud.com

 

[ChaseTruck]

EFI relay too hot?

 

[Can1979]

EFI relay too hot?

Yes, most probably the efi relay

 

[REDrum]

What kind of starter? New OEM, used, Autozone, etc? I have seen starters behave that way.

New OEM, always fires right up when hot wired.

Have you tried a new fusible link set?

I’ve blow a couple usable links, when they go the starter continue to work, just no EFI.

EFI relay too hot?

Interesting thought, that could be it. I have spare which I will try and swap in next time it happens and check to see if thats it.

 

[jonheld]

OMG. Fuel pump? EFI relay? Really folks?
Cmon now, this is clearly a starter logic issue.

 

[Can1979]

From my perspective , it's clearly a relay that is not transmitting electricity .

 

[jonheld]

And why do you think it's not the NSS? It is part of the starter logic circuit.
A post from August:

"The starter circuit is very simple.
The logic side of the starter solenoid: battery positive terminal; fusible link AM1; fuse AM1; ignition switch; neutral start switch; starter solenoid.
The load side of the starter motor is a direct connection to the battery positive terminal."

Nothing else effects the starter circuit. The ECU and the entire ignition system could be in your neighbor's refrigerator and the starter will still crank the engine.

With the key in the START position, you should see +12 at the starter solenoid connection. If not, then work backwards towards the battery.

 

[jonheld]

From my perspective , it's clearly a relay that is not transmitting electricity .

There is no relay in the starter circuit on a US spec 80.

 

[satchel]

Everything Jonheld said is spot on. If you are hearing a click, I would assume you are getting 12v to the signal side of the starter, which will engage the solenoid to push the gear out, but you might not have enough juice on the power side of the starter to turn it. Only thing I would add to what he said is to check the power wire between the battery and the starter, make sure it is clean and getting a solid connection to both.

 

[Desert Dino]

Check your fuel pump, when it becomes hot its not working anymore and check If you face this issue when your tank is fully loaded. If not , then it might be ur fuel pump. Cause the tank is fully filled it will help the pump to keep working properly and the fuel will remain colder.

Not fuel issue hot wire works!

 

[Desert Dino]

US spec 94 I chased this phenomenon for a year frustrated done 2 starter overhauls. Still, after a long drive to the desert in hot weather stop to get gasoline in the last gas station before the wilderness no start some time with click noise some time without.

Nocking on starter wile trying to crank sometimes work

One time stuck on the trail an electrician friend made me a bypass direct feed with big solenoid from the battery directly starter solenoid this solved the problem

I could have left it like this forever, but I like the OEM

In the end it was a combination of 2 problems

Key switch (OEM)
Starter - ( got Denso from Amazon)

 

[Slammy]

Sounds like the same starter problem I had. I carry an ice axe with a long handle. The rare times it happens, usually when it's hot after a long drive, I pop open the hood and tap the starter. Give that a try next time it happens and you will immediately know what the problem is.

 

[REDrum]

Sounds like the same starter problem I had. I carry an ice axe with a long handle. The rare times it happens, usually when it's hot after a long drive, I pop open the hood and tap the starter. Give that a try next time it happens and you will immediately know what the problem is.

Tried that a long time ago...no luck. But thanks.

 

[retlaw]

My LX450 does have a theft deterrent relay in the starter circuit...but if youre hearing the "click" of the starter relay then either the starter relay contacts cant pass enough current or its a bad connection from the battery.. as satchel said.

 

[REDrum]

but if youre hearing the "click" of the starter relay then either the starter relay contacts cant pass enough current or its a bad connection from the battery.. as satchel said.

I was inaccurate in my post, no "click" when in described fail mode. I know the click sound of bad solenoid, and I do not have that.

 

[george_tlc]

Have you done what Jon has requested in post #11? i.e. MEASURE the voltage on the Starter solenoid +ve while the key is in the START position and the problem is present. No voltage and the problem is ignition switch and/or NSS and/or wiring/connectors. Voltage present and then the problem is the starter.

Help us help you...

cheers,
george.