I have a toyota hilux 86 model, 2l petrol. Carb model, 3y motor. Car starts fine and runs without assistance when choke is in operation, once it warms up and choke ceases, motor idles so low and then cuts out. ( car engine is cutting out when I slow for traffic light etc) I am able to keep it running so long as I keep hitting the accelerator to keep the engine revs up. Any ideas, checked all the standard stuff, plugs, leads, distributer cap, air filter, fuel is getting to carb. I have read and another site, maybe fuel cutoff solenoid, would I be able to start the car if this solenoid wasn't operating correctly? Any help would be greatly appreciated. Ta.

It could be the solenoid. An easy test is to have key on and disconnect it then reconnect to listen for an audible click sound.
They hardly ever went bad for me.
What I did do a lot of on your carb model was the AAP diaphragm on the side of the carb. One vacuum line goes to it. See if it's ruptured. Pull the line off when warm and see if it's full of raw fuel. That means you're running too rich when warm.
Of course, the engine needs rich when cold. They are still available and fairly easy to replace.

Thanks kitch, I rang around and got some prices, overhaul kit $100, new fuel cutoff solenoid $250. Managed to get 2nd hand carb assy. With everything for $100. I have just installed and tested new unit. Same fault again, fine with choke on, as soon as revs drops, engine cuts out. I guess its possible diaphragm on both units is defective. Pulled hose off to check for fuel, nothing. Anything else you can recommend? Thanks

Other than than that I'd have to say you have a vacuum leak. A safe way to test is propane (no flame of course) or brake clean, carb clean whatever.
Most suspected areas, carb base gasket, intake gasket, emissions, vacuum lines.
Check and report back.

The AAP is the auxiallary acceleration pump. It's vacuum actuated before the engine warms up. When my AAP went, pieces of it ended up in an inside passage in the carb. The carbs of that era probably had over 120 parts. Re-building took a while. I rebuit three carbs in my life. Two before I reached 16 YO. A 1968 2 bbl, a 1965 1 bbl and an 82 Toyota carb. The first two were cake. I can't remember if I did a 73 Chevy carb. but I had all sorts of troubles with a Holly Economaster carb. Learned to set the mixture using the "propane enrichment" method. Works like a champ.

The EGR valve is another possibility. Pull hose and plug.

Distributer vacuum advances?

The choke pulling off is generally a sign that the engine has warmed up. Vacuum leaks that occur when a system becomes operable. Disconnecting and plugging the hoses to various diaphrams is a good troubleshooting technique.

And the thing that drove me absolutely nuts on a 22R engine was the solenoid mounted on top of the valve cover. That ran full vacuum to the EGR valve with the ENGINE OFF. It was used for anti-dieseling. Valve kept sticking and RPM's would drop dangerously low. That problem was intermittant and a real pain to find.

You might be mistaking the "fuel cut solenoid" for a "bowl vent solenoid".

I don't know the specifics of this vehicle.

Look at it as "a vacuum leak after the car warms up".

"using the "propane enrichment" method. Works like a champ."
Interesting. Would like to hear more on how you set that mixture.
Unless you're just talking about hunting vacuum leaks.

Kitch:
Here is the old post:

https://www.askmehelpdesk.com/cars-t...ml#post1035911

Questions?

Never heard of propane for chasing a vacuum leak, but I see how it would work. Placed in my bag of tricks. Thanks.

Maxi, something just hit me on the head! Take a small ball peen hammer, while the engine is stumbling, tap the top of the EGR valve (may have to be a little aggressive)
If it comes back to life, put an EGR in it. But be warned, all the passages could be clogged with it.

Kiss, thanks!

That EGR test is a long-shot. What I would try first is to plug the EGR hose and let it warm up with it plugged.

The EGR sticking could be a possibility, but you'll at least narrow the system if you plug the hose and start with a cold engine.

At this point in time, it would be wise to inspect all the vacuum hoses.

Another "possible"one is the PCV valve. Shaking is the standard test, but you can plug the hose going to it.

One way to avoid the "one at a time" issue. Is to plug all of the suspected systems at the same time. See if it idles correctly.

If it turns out to be a little intermittant, then plug half of them. Determine which half and plug half of that.

Plug them all and hope engine stays running. Then start to try to re-connect is where I would start.

Brake diaphram leaks would occur when your foot is on the brake.