Stumped

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Joined
Aug 6, 2021
Threads
3
Messages
19
Location
Oregon
Need a bit of help, I have an 84 60 series with a full swap from a 88 62 series. Full drivetrain and interior swap on it. I’ve been having issues when it gets to operating temp not wanting to start after I shut it off while doing errands or just driving it. It will start up after sitting about 10-20 minutes. I’ve combed the mud forums and so far I have replaced the fuel pump, filter, pulsation dampener, pressure regulator, ignition coil, new cap, rotor, spark plug wires, spark plugs, and the efi relay. I’m still having the same issue, it runs perfect when it does fire up but if shut it down it needs 10-20 minutes to cool off before turning over again. Is there something that I am missing? Any help at this point would be a huge help.
 
This is a very frustrating, but not an uncommon problem for the EFI FJ62. The common problem is zeroing-in on a myriad of issues USUALLY, but not always associated with the fuel delivery system. All though the MUD website is a valuable resource, attempting to research historical references is an abysmal study in futility. Other than immediate member responses, skip the MUD research and simply punch “my FJ62 won’t start when hot” into your Google research portal. Not only will you immediately pull up all the MUD references, but also a host of other resources directly related to this FJ62 hot start issue. My issue, many moons ago, was the FPR and just like you, spent a ton of money striking-out until finally hitting a home run. The coolant temp sensor, recommended by “89BIGBLUE” above, is a very sensible next step. Although, not easy and very time consuming, there are methods of testing most of the offending possibilities. The best approach for us non-academic mechanics is read- heed - and, follow your instincts…it’s an invaluable learning experience.
 
This is a very frustrating, but not an uncommon problem for the EFI FJ62. The common problem is zeroing-in on a myriad of issues USUALLY, but not always associated with the fuel delivery system. All though the MUD website is a valuable resource, attempting to research historical references is an abysmal study in futility. Other than immediate member responses, skip the MUD research and simply punch “my FJ62 won’t start when hot” into your Google research portal. Not only will you immediately pull up all the MUD references, but also a host of other resources directly related to this FJ62 hot start issue. My issue, many moons ago, was the FPR and just like you, spent a ton of money striking-out until finally hitting a home run. The coolant temp sensor, recommended by “89BIGBLUE” above, is a very sensible next step. Although, not easy and very time consuming, there are methods of testing most of the offending possibilities. The best approach for us non-academic mechanics is read- heed - and, follow your instincts…it’s an invaluable learning experience.
Thank you I’ll look at it tonight when I get home from work
 
I know nothing about the gasoline guzzlers but aint this problem the carb fan? (on the carb models seems always the problem)
Or this model does not have it (injection)? seems 3F E has it?
And maybe valve settings out of spec?
🔥

 
Did you pull codes? This would be a quick test to find out what is amiss and likely could have skipped most of your parts swapping. Also just for awareness when performing diagnostics - if the only ‘difference’ is engine temp, then usually it’s pretty clear it’s temp sensor related (for efi). Granted there are other options but that’s a quick and easy check for resistance at the sensor.

All of this is covered in FSM also.
 
Did you pull codes? This would be a quick test to find out what is amiss and likely could have skipped most of your parts swapping. Also just for awareness when performing diagnostics - if the only ‘difference’ is engine temp, then usually it’s pretty clear it’s temp sensor related (for efi). Granted there are other options but that’s a quick and easy check for resistance at the sensor.

All of this is covered in FSM also.
I did pull codes, only one I got was for a o2 sensor. I knew the fuel pump was going out and needed to replace it anyway. Which then lead me to swapping most of the other parts.
 
Sounds like vapor lock. carb cooling fan present and working? as @hj 60 recommended above.
Not vapor lock it’s all fuel injected and I pulled the fuel return line and it flows just fine after initial warmup. I did check resistance on the coolant temp sensor and it showed none. Went out and purchased a new one will install later tonight and see if that fixes my issue.
 
Yes but why do the 62s have a carb cooling fan like the 60s have?
Vestigial remnant? 😀
Seriously though, is this fan operational? If not, OP ought to get it running-can’t hurt.
 
Not vapor lock it’s all fuel injected and I pulled the fuel return line and it flows just fine after initial warmup. I did check resistance on the coolant temp sensor and it showed none. Went out and purchased a new one will install later tonight and see if that fixes my issue.
Also look over the connector for the coolant temp sensor carefully, and the wires.
How old is the fuel filter?
 
If fuel was leaking before you replaced the regulator and dampener, it may have gone into some vacuum lines. Does the regulator vacuum line go to the throttle body? If so you have some old fuel in the throttle body with messed up gaskets. It is possible a fuel injector is leaking.
 
Ok so I’ve been busy, swapped the coolant temp sensors, the connectors and swapped the cold start injector connector as they were pretty crusty and worn. Had a friend over and helped check the ecu pins and voltage, only variance we detected was after warming to operating temp for a bit ( about an hour or so) the igt wire coming out of the ignitor to the ecu would pull 3 volts then when warm would pull nothing. So my question is what exactly does the igt wire do? I checked diagrams and it seems to just run from the ecu to the ignitor.
 
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