The past couple days I have been having starting issues. 91 fj80, currently 92k miles. I only have the problem when I have been driving for a while in the hot desert. At first it would be brief, now it takes ten minutes or so to restart. The only other odd thing about the truck (and not sure if they're related) is the fuel tank builds a ton of pressure, the fumes pouring out will moisten your hand, and nearly blow your hair back. Fill up, 30 second later re open the cap, and the fuel tank will lurch. A Buddie of mine mentioned vapor lock, but I have never dealt with that, so I don't know. Thanks.
3Fe starting issues.
- Thread starter mp_cude
- Start date
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i have run into the same starting issue. its the EFI relay in the fuse box under the hood. when it gets too hot after extended driving or hot weather, it wont actuate properly.
the proposed solutions i have seen from on this site are to 1) rewire fuse box (dont know whats up with that), 2) attach a pigtail harness to the connectors in the fuse box and relocate the relay into the cab so it doesnt get hot, or 3) keep a spare relay in your truck and swap it with the VERY HOT (so be careful) relay under the hood. i got a spare from autozone for 12 bucks or so.
by the way, you can check one thing to be sure this is indeed your problem: when your truck is cool and starting the way it should, the orange check engine light will illuminate when you turn the key to the ON position. when the relay is too hot to function properly, this light will not come on while the others still will.
also, did you say you have a 91 with 92000 miles!?!? that is beautiful. i thought mine with twice the miles was in great shape but yours must be cherry.
the proposed solutions i have seen from on this site are to 1) rewire fuse box (dont know whats up with that), 2) attach a pigtail harness to the connectors in the fuse box and relocate the relay into the cab so it doesnt get hot, or 3) keep a spare relay in your truck and swap it with the VERY HOT (so be careful) relay under the hood. i got a spare from autozone for 12 bucks or so.
by the way, you can check one thing to be sure this is indeed your problem: when your truck is cool and starting the way it should, the orange check engine light will illuminate when you turn the key to the ON position. when the relay is too hot to function properly, this light will not come on while the others still will.
also, did you say you have a 91 with 92000 miles!?!? that is beautiful. i thought mine with twice the miles was in great shape but yours must be cherry.
- Thread starter
- #3
Replaced the relay. Fixed the problem. Thanks, if it continues down the road, I'll be on the hunt for another source causing the relay to go bad. It was a taiwanese relay, so maybe it couldn't hold up to the heat. Also the truck mostly sat in tha garage from may of 1990 to sometime in 2005, and problems are just arising. I'll tackle them as they come.
It'll happen again... make sure you carry a spare. Note there are more of the same type of relay in the DS kick panel if your spare happens to burn up.
Other than this, the only problem my FJ80 has ever given me was with the coil, and it was an aftermarket one that died.
Good luck. Post which fix you end up doing and whether it worked for you!
- Thread starter
- #5
So what causes them to get so hot and burn up? The horn relay (same type) was not nearly as hot. Could it be a short, or just a common problem to the 91-92 80's? Also what is the risk if I bypass the relay all together?
my guess is that the gauge of the factory wiring is too small and its constantly receiving current or something like that. then when they heat up, something expands and siezes. this is speculation - im no expert.
you will almost certainly have this problem reoccur in that arizona heat. i would keep the original as a spare for convenience. just swap them and be on your way. if you come up with an easy solution, please do post it
you will almost certainly have this problem reoccur in that arizona heat. i would keep the original as a spare for convenience. just swap them and be on your way. if you come up with an easy solution, please do post it
(condensed)
I re-did the EFI relay wiring the PO had done.
Still had issues. I kept changing out the relay. Still had issues.
I rerouted the EFI relay to inside the cab and even chilled it with AC.
EFI stayed cool and never over-heated.
Was fine for the summer, but didn't take any long trips to verify.
Later, managed to take a long trip and it didn't die on me, but seemed to be heat-related - when hot, no start.
Afterwards, I went back in under the hood, rewired the EFI with all new, larger 10 and 12 gauge wire. This time, I spliced in the new wire at the engine side of the firewall, going to the ECU.
I kept the EFI relay inside the cab but this time I switched to standard Bosch 30amp relay. Easy to find and no longer dependent on the harder-to-find-in-a-pinch Toyota relay.
This seemed to take care of the EFI (relay) prob for good, except - it still had the HOT- NO START prob.
Had battery tested, tested good, but found out it needed an alternator. I replaced the alternator.
THEN, I found the starter was bad; replaced with kit from American Toyota.
Big improvement. EXCEPT - still, HOT - NO START.
Check engine light would come on. But there was no click, no crank, nothing.
Battery good, connections good, fusible links good, +12v at relay box;
It would turn over and start fine when cold, just not when hot.
Already suspecting the coil or the ignition module (igniter), I took a bottle of drinking water and poured it over the coil/igniter. I get in, turn the key, it started right up. Everytime it acted up and I poured some water over the coil/igniter, it would start. Hmmm.
I moved the coil over to the side and piggy-backed a computer heat sink to the ignition module. I sandwiched electrical grease between them and used silicone to keep it in place.
I do have one question, the heat sink works, it gets incredibly hot, but it does the job. So, does the ignition module under the coil normally operate hot?
Maybe this info will help you, maybe it won't.
At any rate, you might look into this to see if that is what you are up against.
Regards
I re-did the EFI relay wiring the PO had done.
Still had issues. I kept changing out the relay. Still had issues.
I rerouted the EFI relay to inside the cab and even chilled it with AC.
EFI stayed cool and never over-heated.
Was fine for the summer, but didn't take any long trips to verify.
Later, managed to take a long trip and it didn't die on me, but seemed to be heat-related - when hot, no start.
Afterwards, I went back in under the hood, rewired the EFI with all new, larger 10 and 12 gauge wire. This time, I spliced in the new wire at the engine side of the firewall, going to the ECU.
I kept the EFI relay inside the cab but this time I switched to standard Bosch 30amp relay. Easy to find and no longer dependent on the harder-to-find-in-a-pinch Toyota relay.
This seemed to take care of the EFI (relay) prob for good, except - it still had the HOT- NO START prob.
Had battery tested, tested good, but found out it needed an alternator. I replaced the alternator.
THEN, I found the starter was bad; replaced with kit from American Toyota.
Big improvement. EXCEPT - still, HOT - NO START.
Check engine light would come on. But there was no click, no crank, nothing.
Battery good, connections good, fusible links good, +12v at relay box;
It would turn over and start fine when cold, just not when hot.
Already suspecting the coil or the ignition module (igniter), I took a bottle of drinking water and poured it over the coil/igniter. I get in, turn the key, it started right up. Everytime it acted up and I poured some water over the coil/igniter, it would start. Hmmm.
I moved the coil over to the side and piggy-backed a computer heat sink to the ignition module. I sandwiched electrical grease between them and used silicone to keep it in place.
I do have one question, the heat sink works, it gets incredibly hot, but it does the job. So, does the ignition module under the coil normally operate hot?
Maybe this info will help you, maybe it won't.
At any rate, you might look into this to see if that is what you are up against.
Regards
Last edited:
Again, does the ignition module under the coil normally operate HOT? Not just warm, but HOT, HOT.
As common as the HOT = No Start prob is on the FJ80 and as hot as the weather has been, I'm surprised no one else has brought this up (recently).
Oh, and if you don't have any water with you, gatorade worked fine - and beer would probably work just as well, too.
As common as the HOT = No Start prob is on the FJ80 and as hot as the weather has been, I'm surprised no one else has brought this up (recently).
Oh, and if you don't have any water with you, gatorade worked fine - and beer would probably work just as well, too.
If the starter motor is not cranking then this has NOTHING to do with the coil/igniter. 2 very seperate circuits. I would look at the neutral start switch on the side of the transmission or simply jump the 2 contacts on the round connector of the NSS on the engine harness side. This will bypass the NSS and allow you to crank the motor in any gear. Also, might be time to replace your fusible links off the positve battery terminal.
The starter circuit is pretty simple on these trucks. The motor side of the starter is connected directly to the battery.
The starter circuit is pretty simple on these trucks. The motor side of the starter is connected directly to the battery.
Take it from someone who knows an 1991. REwire under your fuse box with 12 gauge wiring.Putting in a new efi alone is a temporary fix and will go out again at the worst possible moment. I was stubborn,lazy... went through 10plus efi,s. Finally rewired same efi in for years now. mIke
Have a look at the links below for more info:
http://www.sdsysdesign.com/tlc/images/Strife/3FE EFI Diag.pdf
and
EFI Relay Pics 4 U
There is also at least 100 previous threads on MUD that discuss this issue. Search is your friend.
http://www.sdsysdesign.com/tlc/images/Strife/3FE EFI Diag.pdf
and
EFI Relay Pics 4 U
There is also at least 100 previous threads on MUD that discuss this issue. Search is your friend.
Not my thread and didn't mean to hijack but thanks for the info!
- Thread starter
- #13
The new EFI relay burnt up. It melted at the contacts, and now my spare wont work either. Key on, no engine light. Could the type of failure of the relay have caused issues down the chain somewhere else? Thanks for all the help with this.
I am having this problem currently- but my check engine light always is on when the key is in the on position. I start the vehicle for two seconds (not long enough for anything to get hot)- turn it off- then try to turn it back over and it won't start. I am getting no spark during this time frame--- is there some sort of anti-theft deal that could be going on?
sorry for the hijack hah.
thanks,
Zac
sorry for the hijack hah.
thanks,
Zac
prozautodetail,
please indulge me. do you live in a warm/hot climate?
please indulge me. do you live in a warm/hot climate?
