FJ40 Running Hot Issues

[sr5man]

Hey Guys, newer to the board but got tired of reading so thought i would just post the issues i have. Running a 77 FJ40 in Edmonton Ab. CAN. that i bought from Denver CO. It starts up great and runs like a champion until it gets really warm. After running errands around town for awhile it will:

idle slightly differently (not all the time)
Stall out if I hit the gas pedal to hard
The temp will go up if I stop at a light (not super high or anything)
takes longer to start after a few minutes of being in a store
after turning key off it will "run on" for a second or two
Once parked back at home in garage it feels really warm like can't touch the hood warm.

PO had FJ40 specialist tune up engine and if i recall correctly, found vacuum leak. Valves were also adjusted by PO. Included in box of parts i received was carb kit....

Thanks for the help.

 

[FishTacos]

Sounds like it is running rich.

Your carb probably needs some adjustment.

As for running hot, does your overflow bottle fill up after a trip around town?

Could you post some pics of your carb from various angles?

 

[JAFO2014]

Regarding running hot, my FJ40 was new to me and I didn't want any running hot issues, so I replaced the thermostat right off. Trucks run hot for the typical reasons....bad thermostat or poor (restricted) water flow. You can have radiators flow tested. You can test your thermostat by putting it in hot water with a thermometer to verify when it opens and closes.

Remember that valves too tight is way worse than valves too loose. Valves cool when they close. Valves too tight is when you chance a burnt valve. And their adjustment can affect the engine. You might want to check the valve adjustment if you question whether the PO did it correctly.

I'm fighting some carb issues with my 1977 FJ40. It was de-smogged and I think vacuum lines are wrong and maybe I have a vacuum leak. But it is not acting like yours. Mine just has a flat spot when I am accelerating. Idles fine. Runs down the road fine.

Good luck.

 

[91 4runner]

ok, u have multiple problems it sounds like,



lets start with temps rising at a light,

that is normally an air flow issue, insure our fancluch is in good order, and that your radiator fins are clean and free of debris, and for kicks be sure ur waterpump/fan belt it tight, start there and see if things check out,



intermittent idle speed problems, dieseling and stalling under a quick throttle snap,hard starts, are signs of a large vacuum leak,on a 2f the most common is the manifold to head mating surface, use some carb cleaner and spray all of the mating surfaces (manifold to head, carb to manifold, and carb body its self) and listen for an increase in engine RPM if RPMs do increase then u have un metered air entering your engine, new gaskets should stop ur leaks and settle the 2f down,

 

[sr5man]

That is great! I think I can actually handle that stuff myself. Thanks. And yes FishTacos i will post some pics when i get home tonight. I'm eager to try these various fixes.

 

[shawnfj40]

Next time it is acting up while running try removing the gas cap. If you hear a loud sucking sound when you remove it then you are getting vapor locked. That will cause the run on and poor warm starts. It will require you to dig into the tank venting and canister condition if that turns out to be the problem.

 

[sr5man]

Hey FishTacos sorry this took awhile. Hope this tells you something.



...via IH8MUD app

 

[sr5man]

Ok Shawn thanks. My signal lights just stopped working so that's the first thing I'll have to attend to.....


...via IH8MUD app

 

[91 4runner]

i doubt hes haveing vapor lock isues, plus it looks like the stock fuel return line is in place, i only see thoes problems when the fuel delevery system has been hacked with, speeking of hacked did you do the "de Smog"?

 

[sr5man]

I never did the de smog. it was either the PO or Rob Antonson (the fj40 wiz that did tune up for PO) does everything look ok?

 

[FishTacos]

Robbie is a highly respected grease monkey for sure. My roommate took his mini truck to his shop back when I was in school at CU. Always raved about his work. I would suspect the desmog was done by the PO but You could call Robbie and ask what he did to the rig and when.

 

[sr5man]

hey was actually just reading the report he sent to PO. Robbie actually found and fixed vacuum leak at the manifold and found the vacuum booster to be leaking as well. upon removing the manifolds he found the manifold gasket to be leaking exhaust as well as the manifold to pipe gasket. he changed them both. He also adjusted the carb as the "idle mixture was way off, the high speed cold idle was jack up and the normal idle was not adjusted right either". once it was adjusted properly he noticed the valves needed to be adjusted (which the PO did). That's all i know. When i brought it to my mechanic he upped the idle right away. I might take it back down a bit though.

 

[GA Architect]

I can't tell from your photos, but where is the dizzy vacuum line hooked into? I have the exact same type '77 set-up as yours, being a high altitude carb. If you look at your photo #2 above, it appears that the vacuum lines into port #5 & #13 are possibly capped. In a desmogged setup, I believe your dizzy line should connect into port #13.

I went by the desmog diagram from subzali within this forum.

I updated my desmog vacuum routing per the Jim C. - High Altitude carb desmog diagram I posted below, see post #20.

 

[sr5man]

ok i'm gonna check the diagram and try and figure out which line is the Dizzy vacuum line?

 

[Bret]

Not sure what your altitude is but if it was adjusted for Denver the timing may be off a little and the carb may be leaned out a smidge. Running lean creates a little extra heat in the system from what I remember.

 

[GA Architect]

Check the vacuum line coming off the side of the distributer.

 

[sr5man]

hmm will have to carry this on later but thanks for the help guys. my 5 and 3 year old girls are awake and now my 5 month old son is up too so....getting ready for church. will check back this afternoon. Thanks again.

 

[GA Architect]

For reference, here's the 2F desmog diagram I mentioned.

 

[OR40]

Checking an old thread for answers....similar situation with my 77'. Has a Holley on board, same dieseling and throttle cut out when gassing it. Did yours end up being the seal between surfaces? De-smogged improperly?

 

[GA Architect]

Being it was brought back up....I'll update my post in this thread. Per Jim C., the high altitude carb desmog should look like this: