Solenoid valve connection

[edhCO]

I have searched Haynes & Chiltons manuals for the place the solinoid valve connects. I am having a "moment" and would like some direction. See attached image of what I am describing. a pic response would be great but maybe unnecessary.

Thanks in advance.

 

[Poser]

A 12 volt source that has power when the ignition key is in the 'on' position....

 

[edhCO]

so unnecessary?

So I guess it is unnecessary, It starts w/o connection.
P.S. De-smoged.

Or would it improve starting performance?

 

[Poser]

So I guess it is unnecessary, It starts w/o connection.
P.S. De-smoged.

Or would it improve starting performance?

It is hardly unnecessary and de-smog has nothing to do with it....




That solenoid is an idle solenoid, or also known as an anti-dieseling solenoid. Its function is to prevent fuel from being sucked through the idle circuit at shutdown and causing run-on.


The truck will run very poorly, if at all, with the idle solenoid not connected to a 12 volt source when the key is in the on position.


Make a jumper wire to your positive terminal on the battery and just touch the wires together; you should hear a very audible click, which would indicate that the solenoid has opened and is functioning properly.


If you hear a click, I would then hook the solenoid up to a switched 12-volt power source and then see how it operates.

 

[edhCO]

connection made

Thanks Poser!
"click" is audible. Connected solenoid up to a switched 12-volt power source. I have battery on a charge... I left the key turned all last night, so I cant turn the engine over. I will test tomorrow... maybe the carb won't need a rebuild! (lots of idle issues, .. funny thing)

Many thanks.

 

[Poser]

You are lucky; the points must have been open and not closed.


Had they been closed, you would have been purchasing a new coil, because the battery voltage continuously flowing through the coil would have boiled the oil and eventually caused the coil to detonate.


Be sure to switch the key to the off position when done playing with the Land Cruiser.





Post up what you find out.

 

[edhCO]

....?

So I have connected the solenoid valve, it does seem to idle better (especially after a cold start, I used to have to keep the gas pedal always at the ready if idle became too low) before engine is warmed up.

But an interesting ghost has popped back up. At idle, if the brake pedal is depressed the engine RPM's start to climb, proportionately to the amount the pedal is depressed. I'd say it climbs around 800-900 RPM just in the pedal pressure. (No tach, just an audible guess) There is the same audible solenoid "click" when pedal is depressed then idle climbs.

When I disconnect the solenoid valve, and depress the brake pedal... no increase in engine RPM. Engine is capable of running without solenoid connected...?

So- guesses:
1. Is my carb. just way out of tune?
2. Could this be a vaccum leak? if so, how do I chase this monkey down?
3. Or is the 12v power source, the wrong wire of choice?
4. Is this the way it is supposed to be?

Ethan

 

[Trollhole]

I don't even think your engine should even idle without that solenoid connected. If it is, someone has turned the idle screw in. Don't work backwards work forwards. It is a fact the idle solenoid has to be connected for the engine to run right. Now that you have it connected to a switched 12v work on figuring out why your idle is so high.

Is your choke engaged? Is the carb linkage bent? Can you see that the idle screw when turned out is still making contact with the idle linkage.

You sure your choke is not out?
You sure your choke isn't out?
You sure the choke knob isn't pulled out?
Are you sure the choke butterfly is open all the way?

 

[Poser]

Adding to what the Troll has posted:




What year is your truck? It would appear to have a 2F engine, but I am not going to assume anything.

Do you have mechanical linkage to the carburetor?

Is there a possibility that when you press the brake pedal, that something under the dash is contacting the accelerator linkage and increasing the engine RPMs?

 

[edhCO]

Moving forward.

I am all for moving forward!

12/75 ('76)
2F- Aisian carb. - OEM mech. fuel pump

The choke is open.( see image)

but I don't think the idle screw is contacting the idle linkage. The fast idle connecting link is pretty loose. (see image 2)

P.S. I am pretty green around the ears with carbs...

I believe I have mechanical linkage to the carburetor, & I looked for anything contacting accelerator linkage & the brake pedal and nothing seen.

LEt me know how you would proceed... THanks!

 

[Coolerman]

The audible click you hear when pressing the brake pedal is the brake switch activating.

You could have a vacuum leak in the brake booster. When you press the pedal do you also hear a hiss or sucking noise? Normally a vacuum leak causes idle to go down not up.

 

[edhCO]

NO hissing sound or sucking with brake pedal depressed.....?

Where does the vaccum leak occour on the booster, could it be an internal issue? the external hose connections seem tight.

 

[Coolerman]

Yep, internal rupture of the diaphragm. You'll know it when you hear it...

 

[edhCO]

Then... would you replace the booster with a new OEM... or from someone parting out? I ask because if it is unseen, how will I know if the replacement booster will have the same issue?

 

[Trollhole]

Take a pair of locking pliers and clamp off the brake booster line. Does the idle change when you apply the brake?

The fact your idle screw is not making contact makes me think your gas pedal linkage needs to be adjusted. Disconnect the carb from the linkage. on the firewall side of the carb there will be a rod that connected to your carb. (part #52. Remove it. Takes a little bit of force put it will pop off. Don't loose the clip.

Part # 52

With it off does your idle screw come in contact with the set plate? If it doesn't something is bent or stuck. If it does adjust the idle screw to where you idle at around 650rpms. Then adjust the linkage so it doesn't open raise the rpms at idle.

The bottom yellow screw is the idle screw. I believe the top yellow screw is the choke breaker.


Something tells me it's probably your brake booster though.

 

[Pin_Head]

The idle solenoid should be connected to a fused, switch on, power source and not the ignition coil (which is not fused). You don't want another wire connected to the coil with the possibility of shorting out and killing the engine while you are driving as this may be a safety problem. The voltage regulator power wire (black/yellow stripe) is a good choice if you cant find the original wire.

Your carb has probably been adjusted to compensate for the lack of idle fuel by increasing the idle speed screw so that it will run off the main nozzle. When you hook up the idle solenoid, you need to adjust it properly so that it will run off the idle circuit. This also provides fuel for the transition slot that will prevent bogging down when you acccelerate off idle.

Your brake booster has a vacuum leak as others have mentioned.

 

[edhCO]

Follow up

I wanted to follow up, & let you know some of my findings.

I connected the solenoid valve to a switched 12-volt power source... However, after driving on it for a while, it still didn't seem right...(still would stall cold, etc.) & the brakes were still increasing engine idle speed when the pedal was depressed. I could hear the audible click of the solenoid with my brakes depressed.

I found the voltage regulator power wire (black/yellow stripe) (Thanks Pin_Head ) And guess what... no more engine idle issues with the Brakes Depressed.

My Carburetor had been tuned by "that guy who really knows cruisers" who in turn had screwed around with the idle screw and had the idle set at approx 1400 RPM. It always ran like s*** untill it had warmed up and I was always at the ready with the gas pedal to keep it from stalling.

So, I have adjusted the carburetor (Thanks AgAIn to Pin_Head ) and it is running better than it ever has before in my possession. I know more about my truck, and have it running better than "that guy who really knows cruisers"

I am hoping for my fuel economy to improve somewhat... but we shall see.

Now I am trying to figure out timing and vacuum. Thanks again to all of you for your help!