Carbureter woes - '70 FJ40

[Searcher356]

Working on 1970 FJ40, Build date Aug 70. It's been sitting for a couple years with only a few one or two mile trips. Filled the tank with fresh fuel and took a 40 mile shakedown run, 1000' gain in elevation at 65 mph and back. Ran great. Parked for 30 min. Restart OK but only ran for 2 minutes, then shut down abruptly, like ran out of gas. Carb cleaner got it to run for 2-3 seconds. Pulled jet covers to drain float bowl, it was dry. Fuel solenoid clicked with key on/off.
FINALLY LOOSENED FUEL SOLENOID TWO TURNS EACH SCREW AND IT STARTED RIGHT UP AND RAN.
While running, retightened solenoid screws - shut right down. Loosened screws and drove home. Loose now. Sight window shows fuel level right at set line.
Haven't had time to open the sediment bowl and look for debris or rust, or change the fuel filter. So I might have "stuff" in my tank - don't know. But it looks like the fuel pump is working just fine, and the filter isn't clogged, because the float bowl fills RIGHT AWAY when cranking. It doesn't overfill either, so it looks like the needle & seat are OK too.
Any experience with the fuel solenoid?
The '40 is out of town now, so I am tying to plan my trouble-shooting and parts I might need before I go back to pick it up. (65 miles away)
Any ideas or suggestions?

 

[Pin_Head]

The inlet needle valve is sticking closed for some reason. It also sounds like your idle circuit is plugged. All this points to time for a clean out / rebuild. If you find dirt, you want to clean the entire fuel system at the same time from tank to carb.

 

[danisirish69]

Working on 1970 FJ40, Build date Aug 70. It's been sitting for a couple years with only a few one or two mile trips. Filled the tank with fresh fuel and took a 40 mile shakedown run, 1000' gain in elevation at 65 mph and back. Ran great. Parked for 30 min. Restart OK but only ran for 2 minutes, then shut down abruptly, like ran out of gas. Carb cleaner got it to run for 2-3 seconds. Pulled jet covers to drain float bowl, it was dry. Fuel solenoid clicked with key on/off.
FINALLY LOOSENED FUEL SOLENOID TWO TURNS EACH SCREW AND IT STARTED RIGHT UP AND RAN.
While running, retightened solenoid screws - shut right down. Loosened screws and drove home. Loose now. Sight window shows fuel level right at set line.
Haven't had time to open the sediment bowl and look for debris or rust, or change the fuel filter. So I might have "stuff" in my tank - don't know. But it looks like the fuel pump is working just fine, and the filter isn't clogged, because the float bowl fills RIGHT AWAY when cranking. It doesn't overfill either, so it looks like the needle & seat are OK too.
Any experience with the fuel solenoid?
The '40 is out of town now, so I am tying to plan my trouble-shooting and parts I might need before I go back to pick it up. (65 miles away)
Any ideas or suggestions?

Get ahold of Jim Chenowith (FJ40Jim). He is a master at j40 carbs and ignition systems.

 

[Searcher356]

The inlet needle valve is sticking closed for some reason. It also sounds like your idle circuit is plugged. All this points to time for a clean out / rebuild. If you find dirt, you want to clean the entire fuel system at the same time from tank to carb.

I do suspect some contamination, maybe even some rust in the system. And, for sure, cleaning it all if that's what it is. Or at least doubling up on filters until the bigger project can happen.
The needle magnetic valve moves freely and with authority, so it might be a rock seated against the Economizer Jet, but that shouldn't cause it not to run, or would it?

But what I am trying to do right now is make it drivable for that 65 miles back home. If the fuel filter / sediment bowl are doing their job, I can deal with a rusty tank later. But that may not be the problem - still troubleshooting from afar.

So, another question:
Why would you suspect the idle circuit is plugged? It idles just fine, when the magnetic valve is unseated. On other 40's, I have used the loosen/tighten the mag valve technique to clear things, like when 100 miles from civilization on the side of a mountain, but not this time.

BTW, I am looking at my Toyota Engine repair Manual and I don't think my carb is like the one used in the manual. I have seen three different carbs on F145 engines.
This one doesn't have a smog pump.

 

[Pin_Head]

What needle valve? If you are talking about the needle on the idle fuel solenoid, you shouldn't have to loosen it to get it to run. It suggests that there is some dirt in there. If you just need to get it home, then you don't need an idle circuit at all. Just bump up the idle speed screw to 1000 RPM.

 

[Searcher356]

What needle valve? If you are talking about the needle on the idle fuel solenoid, you shouldn't have to loosen it to get it to run. It suggests that there is some dirt in there. If you just need to get it home, then you don't need an idle circuit at all. Just bump up the idle speed screw to 1000 RPM.

Thanks for responding. You called it a needle valve in your first response, I called it the magnetic valve. Maybe we're not talking about the same thing.
No matter, I am talking about the solenoid-operated "emission control" valve that clicks with the key on. The manuals call it the magnetic valve. It has a long "needle" that reaches horizontally into the carb body.

You are right, if there is just some dirt in there I should be able to just power on home, kind of ignoring the idle circuit. Opening the throttle plate, as you say, will transfer manifold vacuum further up the carb and enough fuel should flow to get going.
But the problem is - it just won't run with the magnetic valve fully seated. It won't start, even with starting fluid (it fires and revs but immediately stalls out).
Back off the screws on the mag valve and it runs, idles and accelerates just fine.
I'm not confident that this won't cause problems on the 65 mile drive over a mountain pass, so I'm scratching my head.
If the magnetic valve affects the idle circuit, but it won't run at all unless I unseat the mag valve, what is it? Does the Mag Valve also control fuel flow into the float bowl, and without it I am effectively out of gas?

Now the rest of the mystery - and I'm not sure about this because it was dark and I was using my phone screen to see while I went through the initial troubleshooting.
When it wouldn't run, the float chamber was dry. I removed the jet covers (nuts on the lower front of the float bowl) to flush the bowl and nothing came out, and the fuel wasn't visible through the sight glass.
Then I loosened the mag valve screws and it ran. I tightened the screws and it shut down. I re-loosened, it ran, and I scurried home.

(The tools I had during this nightime episode were a passer-by with a crescent wrench and a can of starter fluid, another with a Swiss Army Knife, and my cell phone screen. I was happy to get home, as unprepared as I was!)

 

[Pin_Head]

I was talking about the "inlet needle valve" which lets gas into the carb bowl and sets the fuel height. The fact that your bowl was empty suggests that this needle valve was stuck closed. Often you can unstick it by rapping the fuel inlet with the handle of a screwdriver.

You are talking about the idle fuel cut off solenoid that has nothing to do about smog control and prevents run on after you shut the key off. The fact that you have to unscew it to get it to idle suggests it is clogged. It has nothing to do with high speed operation. If you have to unscrew this to get it to run suggests either that it is an unrelated intermittent problem or you are hallucinating.

 

[Searcher356]

I was talking about the "inlet needle valve" which lets gas into the carb bowl and sets the fuel height. The fact that your bowl was empty suggests that this needle valve was stuck closed. Often you can unstick it by rapping the fuel inlet with the handle of a screwdriver.

You are talking about the idle fuel cut off solenoid that has nothing to do about smog control and prevents run on after you shut the key off. The fact that you have to unscew it to get it to idle suggests it is clogged. It has nothing to do with high speed operation. If you have to unscrew this to get it to run suggests either that it is an unrelated intermittent problem or you are hallucinating.

"Inlet needle valve," as in "needle and seat." Right, it's what is opened and closed by the float. That's why I corrected my terminology to "magnetic valve." I'm not talking about that, although as part of the troubleshooting I did rap all about the carb to see if I got fuel flow. Didn't work.

Among other things, I was talking about what Toyota calls the Magnetic valve, which you call the idle fuel cutoff solenoid. That's what the Magnetic Valve does - prevents after-run.
You are right, it should have nothing to do with high speed operation, as we agreed in the previous exchange.
Having to loosen it to get the engine to run suggests that is another problem. That's what I have been trying to uncover with this post.

I have tried all the usual field troubleshooting approaches, but I end up with a car that runs with the Magnetic valve backed off, but not with it tightened.
So, Mudders, what other possibilities could contribute to this unusual observation?

Not related to troubleshooting, but for the record - the magnetic valve (solenoid fuel cutoff) WAS a Fed requirement in the early days of emission controls. It was designed to stop engine run-on after shutoff, and dribbling or boiling-over of fuel from the float bowl as it sat, particularly when the engine was still hot.

 

[honk]

"Solenoid valve" is how I see your magnetic valve described in manuals but who cares what it's called - the fact that your truck will run with it loosened and die with it tightened DOES indicate that some sort of matter is in residence where the electrically closed valve seats for closure.

It, by the way, was not federally mandated. It was a Toyota solution to the problem of run-on which occured in all likihood because of the implimentations made by Toyota in their efforts to meet increasingly stringent emmisions standards which were the only thing federally mandated, then as it is now.

Now, I'm going to tell you two things which even in your silly mindset are inarguable facts, OK?

The first is that your solenoid valve is a problem for you.

The second is that you are making a fool of yourself argueing semantically with one of the most widely acknowledged Toyota FJ40 " gurus" who post most helpfully in this site.

So why don't you put your petty little ego into your pocket and start to think and listen. What you got goin' on ain't that big a deal.

 

[Pin_Head]

No offense taken.
I probably shouldn't have described the loose screw results as a "hallucination", but it is so bizzare that it made my head explode.

After thinking about it longer, I have seen idle fuel cut off solenoids cause trouble with running when they are connected to the coil + and then short out the coil and cut out the spark. Maybe loosening the screws ungrounds the solenoid so there is no short. The solenoid should be connected to the "engine" fuse circuit at the voltage regulator under the brake booster. That way it won't take out your ignition if it shorts out.

 

[Searcher356]

"Solenoid valve" is how I see your magnetic valve described in manuals but who cares what it's called - the fact that your truck will run with it loosened and die with it tightened DOES indicate that some sort of matter is in residence where the electrically closed valve seats for closure.

It, by the way, was not federally mandated. It was a Toyota solution to the problem of run-on which occured in all likihood because of the implimentations made by Toyota in their efforts to meet increasingly stringent emmisions standards which were the only thing federally mandated, then as it is now.

Now, I'm going to tell you two things which even in your silly mindset are inarguable facts, OK?

The first is that your solenoid valve is a problem for you.

The second is that you are making a fool of yourself argueing semantically with one of the most widely acknowledged Toyota FJ40 " gurus" who post most helpfully in this site.

So why don't you put your petty little ego into your pocket and start to think and listen. What you got goin' on ain't that big a deal.

I didn't mean to offend. I have seen some of his ideas on the forum and they were good.
Just trying to sync my terminology with his (not argue semantics) to describe my problem, looking for a solution.

You are correct, and I overstated, that Toyota's solution to the 1968 Fed Evaporative Emissions standard wasn't mandated – the mandate was that they comply with the standard. Different manufacturers used different techniques, although most used the fuel shutoff thru 1974.

Pinhead and you both agree with me that there is a problem that is alleviated when I loosen the "solenoid valve." We all agree that crud in the system is a possible culprit. Loosening it is a troubleshooting technique that I developed in the early 70’s and still find it useful.
As Pinhead and I know, the solenoid valve affects the low speed circuit, so off-idle operation should still work - maybe not smoothly, though.
But it doesn't, in this case.

So let me restate.
I have an FJ40 with the symptoms I described in my first post. It's 65 miles away. I need to retrieve it.
I am looking for ideas about getting it back home.

 

[Searcher356]

I don't want to disassemble the carb in the field - I learned that lesson decades ago. Too many little springs, bushings and balls that don't appear in diagrams and manuals that can disappear into oblivion if not on an organized bench. I think I have a complete kit for the carb in my parts room, from back in the day when Toyota kits even included new floats. And a couple partially-raided kits. But I want to get back to my shop to do that work.
What I am thinking is to go to Salida (where the '40 sits now) armed with tools, a dental pick and mirror, a can of carb cleaner, and a new fuel filter and sediment bowl gasket.
I will also have the advantage of daylight and my headlight this time.

I'll remove the sediment bowl, look for crud, and replace the fuel filter. (The current sediment bowl is metal so I can't peer into it. I have a complete NOS assembly with glass bowl in my parts room that I'll take if needed.)

Then I'll try pulling the "solenoid valve," look in there and inspect the tip of its needle. Maybe probe a bit and flush with carb cleaner. Check for movement of the needle when 12v is applied. Hopefully, reassemble and drive right home.​

I haven’t had a F145 carb apart in years, so I have a question before I get in there. (Again, this will be on the car, not a bench.)
Is there a bushing and/or check ball associated with the solenoid valve that might either stick in or fall out when I pull the assembly?
I kind of recall a bushing that locates the needle towards its seat, which can be removed to disable the entire valve.
I don't want to loose the innards if they are loose and I need them.

 

[Searcher356]

No offense taken.
I probably shouldn't have described the loose screw results as a "hallucination", but it is so bizzare that it made my head explode.

After thinking about it longer, I have seen idle fuel cut off solenoids cause trouble with running when they are connected to the coil + and then short out the coil and cut out the spark. Maybe loosening the screws ungrounds the solenoid so there is no short. The solenoid should be connected to the "engine" fuse circuit at the voltage regulator under the brake booster. That way it won't take out your ignition if it shorts out.

Interesting thought about grounding the ignition. It's possible because the wire comes from the coil. But when my passerby sprayed starting fluid, the engine fired and ran for a few seconds, so I ruled out "no spark" as a problem. But I don't remember where I was in the loosen-tighten-loosen-the-solenoid sequence , so it's a definite possibility. Thanks.

Actually, I thought all those solenoid wires came from the coil - the reason for the little standoff tab on the rocker cover. But the regulator sounds like a less vulnerable wire route, anyway.
edit> I think the solenoid still clicked, tight or loose, but this all happened a month ago ,I didn't make notes, and I haven't seen it since then. Maybe I AM hallucinating....