FJ60 Won’t Hold Idle (1 Viewer)

[ryyount]

Hey all! Read through a ton of posts the last few months and learned a ton. Hoping to describe my specific problem and see if anyone has any pointers outside of everything I’ve been searching.

1986 FJ60 (fully smogged). Bought as a non-runner, though it would crank and start, just died after that.

So far I’ve disconnected the fuel tank and run off a clean 5 gal jug (send and return from fuel pump). There is consistent fuel in the bowl, halfway up. Run through every vacuum line, cross referenced with the emissions manual, everything seems to be routed to spec. I removed the carb, pulled the idle screw and cut solenoid out for cleaning. Blasted cleaner through both jets. The cut solenoid is operating correctly, even tried grounding it as many others have suggested, no different.

I’ve got the truck to start and hold idle around 1200-1500 on choke, and once warm it holds around there off choke. At this point, any adjustment to the idle mixture screw changes nothing. Unplugging the idle cut solenoid changes nothing. I can give it throttle and it runs up and down very smoothly, just can’t back the idle speed screw down past 1200 or so without it dying immediately.

Any suggestions where to go from here? Seems like it might be a vacuum / intake leak big enough to negate the idle circuit, and I’m actually idling off the slow jet?

Any help is appreciated!

 

[OSS]

Did you check the engine vacuum at fast idle?

 

[ryyount]

Did you check the engine vacuum at fast idle?

I haven’t. Don’t own a vac gauge yet. What’s the best way to connect it to the system?

 

[Spike Strip]

After you removed the Idle cut solenoid, did you make sure the idle circuit was not obstructed? Easy for bits of the O-ring (on the tip of the ICS) to crumble and get bits stuck in the circuit, particularly if ICS is removed for inspection.

My guess is a carb rebuild is in your future.

 

[ryyount]

After you removed the Idle cut solenoid, did you make sure the idle circuit was not obstructed? Easy for bits of the O-ring (on the tip of the ICS) to crumble and get bits stuck in the circuit, particularly if ICS is removed for inspection.

My guess is a carb rebuild is in your future.

Yes, O ring came out intact on the solenoid. I did this with the carb on the truck, so I did my best to shoot carb cleaner through where the solenoid threads in (with the idle screw removed). Blasting compressed air after that. Guess there’s a chance the idle circuit could be clogged from the float bowl to there?

 

[OSS]

What’s the best way to connect it to the system?

While you’re troubleshooting, just get one of those hand pump vacuum gauges sold at any auto parts store.
Hook it up the the little L vacuum pipe that’s jutting off the brake booster fitting on the intake manifold. The AC idle up vacuum hose normally connects there.

 

[Spike Strip]

Yes, sure seems like something in the idle circuit if all the ICS tests check out. Particularly if your engine vacuum is ok, and it holds RPM above 1200 without stalling, and the full level in the sight glass remains at the 'middle' level while running and after stopping the engine.

Sounds like you're trying to avoid a rebuild, but if you've got an almost 40-year-old truck with the original untouched carb...

 

[ryyount]

Yes, sure seems like something in the idle circuit if all the ICS tests check out. Particularly if your engine vacuum is ok, and it holds RPM above 1200 without stalling, and the full level in the sight glass remains at the 'middle' level while running and after stopping the engine.

Sounds like you're trying to avoid a rebuild, but if you've got an almost 40-year-old truck with the original untouched carb...

View attachment 3486068

Totally fine with tearing into a rebuild. Actually already ordered the kit. Just wanted to get other opinions on it. I’ll get a vacuum test going and see what we’ve got.

 

[Spike Strip]

I obviously don't know your skill or experience level, so just a friendly FYI: Don't try and remove the shafts or anything in the throttle body, soak and clean as is, then blow out. Very difficult to remove the flow-thru set screw in the bottom without the proper driver set (or you can make one). Chances are good you'll bugger it without proper-fitting tool (fat tip in the middle of pic below).

Good luck. Subscribe for ease of posting pix.

OEM Carburetor Driver Set for Any Toyota

Toyota OEM carb adjustment driver set.

www.cityracerllc.com

 

[ryyount]

I obviously don't know your skill or experience level, so just a friendly FYI: Don't try and remove the shafts or anything in the throttle body, soak and clean as is, then blow out. Very difficult to remove the flow-thru set screw in the bottom without the proper driver set (or you can make one). Chances are good you'll bugger it without proper-fitting tool (fat tip in the middle of pic below).

Good luck. Subscribe for ease of posting pix.

OEM Carburetor Driver Set for Any Toyota

Toyota OEM carb adjustment driver set.

www.cityracerllc.com

View attachment 3486109

Thanks for the heads up! Just thinking about this.. is it strange at all that the idle solenoid doesn’t affect the truck plugged in or unplugged when it’s idling at 1200? In my understanding that should kill the truck. I have confirmed 12v and heard the click with ignition on.. am I overlooking something simple?

 

[BlackCat]

Thanks for the heads up! Just thinking about this.. is it strange at all that the idle solenoid doesn’t affect the truck plugged in or unplugged when it’s idling at 1200? In my understanding that should kill the truck. I have confirmed 12v and heard the click with ignition on.. am I overlooking something simple?

at 1200rpm its no longer running on the idle circuit its pulling from the main jet. So cutting power to the solenoid won't have any or minimal effect.

 

[ryyount]

at 1200rpm its no longer running on the idle circuit its pulling from the main jet. So cutting power to the solenoid won't have any or minimal effect.

That’s what I figured. So the options are… idle circuit clogged or enough of an intake leak to negate the amount of fuel the idle circuit supplies?

 

[BlackCat]

That’s what I figured. So the options are… idle circuit clogged or enough of an intake leak to negate the amount of fuel the idle circuit supplies?

yep, you're on the right track. A vacuum gauge will help, and you can even try rigging up a home made smoke machine to push some smoke thru the intake to see if you can visually spot a leak. The truck is 40 years old so don't count out on wild cards like it has a massive vacuum leak AND the carb is clogged. Look into Remflex intake/exhaust gaskets if you find a leak and take a good look for cracks in the intake manifold under the heat riser once the carb is removed.

what do the plugs look like?

 

[Paullus]

The EGR j-tube can get rusty and loose.

 

[ryyount]

The EGR j-tube can get rusty and loose.

Interesting. Was messing around spraying carb cleaner while it was running today. Seems like if I spray it on the front of the intake under the carb it revs. Right where the egr and pcv meet at the intake. Looks like it’s got a gasket and a ton of orange stuff (rtv?) smooshed. The bolts are turntable. Guess that would be a massive intake leak if it’s pulling air there? Where would I get that gasket?

 

[Spike Strip]

Pix

 

[MrMacdugal]

gasket OEM part # 25628-61050

 

[ryyount]

Pix

 

[BlackCat]

IIRC the Remflex combo comes with that gasket (although OEM is fine too) and you're more than likely going to need a Remflex intake/exhaust gasket anyways. I would highly suggest coming up with whatever method works best for you after googling to smoke your intake and see all the other leaks. You don't want to seal that particular leak up just to take it all apart again to replace something additional.

 

[ryyount]

IIRC the Remflex combo comes with that gasket (although OEM is fine too) and you're more than likely going to need a Remflex intake/exhaust gasket anyways. I would highly suggest coming up with whatever method works best for you after googling to smoke your intake and see all the other leaks. You don't want to seal that particular leak up just to take it all apart again to replace something additional.

Totally, I plan on stripping it down all the way and putting new gaskets on the whole system. From the looks of it, this kit only has the egr attachment to the exhaust manifold right? The one I was mentioning would be diamond shape but bigger semicircle hole.