Ok so a few weeks ago I ran my 87 Toyota pickup real low on gas. It has a 22R. On my way to fill it up it started idling really rough to where it wanted to die. A few days later I cleaned the carb, changed the plugs wires rotor cap fuel filter and air filter. It seemed to help for a little bit. But then it went back to idling rough after I would wind it out to about 4000 rpms. When i park it and start it back up a little bit later its fine. But once i wind it out again it started actin up again.
Then today i was drivin it and now it either idles really rough to where it almost dies, or it idles at 1500 rpm or higher, all the way up to just over 3000 rpm.
I have no idea where to even begin looking to try and diagnose the problem.
I NEED HELP this is drivin me crazy!

 

Carburetor float level?
Needle valve sticking?

 

Yes, definitely check the float level first. The fuel level is visible, or should be, in the sight glass.

The fuel level affects all of the carburetor circuits.

 

Subbed. Even though I have a weber and really good with carb's I had this issue at my last bog. Broke a timing chain shortly after. I don't think it's related to the timing chain, but who knows. Another thing I have noticed afterwards, is that my choke isn't automatically engaging. Pressing on the choke plates and operating the throttle gets it to engage, but it doesn't engage on it's own.

 

A couple things should happen with an automatic choke...
Cold start, step on the pedal and the choke plate(s) should be pulled over and shut, and a cam should engage the throttle to hold the throttle open a touch.
If it's not flipping shut and holding the throttle open on its own, there may be an issue with the pull-off coil not being adjusted correctly, the choke plate shaft may be bent or the bushings or linkage may have simple dirt interference.

 

also i forgot to add that when i shut the truck off with the key it says running. it doesnt shut off immediately. it delays then shuts off as of today. which i also have no clue which would cause that. im hoping they are related. because they both started at the same time.

 

Possibly the fuel cut solenoid.

 

x2. Sounds like that's not shutting properly. But should be completely unrelated to your idle issues. As far as my choke adjustment, it's only a 3 year old carb and the choke is adjusted from the factory. My choke plates move freely by hand.

 

x3

Here's some pictures of the Fuel Cut Solenoid. The first on is where it is located on the carb. The second shows a description of what it controls. The second pic doesn't show the shading very well to denote the fuel passage of the idle circuit.

The Fuel Cut Solenoid blocks the passage way the the fuel would travel to the idle port.

 

The ONLY thing that fuel cut solenoid control is fuel going into the carb's idle fuel. It does not control the fuel bowl vent, nor does it control the choke. Toyota is not a feeedback carb system.

 

ok ill check it out when i get it back home next weekend. Im off at college, and most of my tools are back home but hopefully soon i can take a look at it... i might just switch over to my weber though.. so i don't have to deal with the toyota carb anymore.. thank you guys for responding. ill be checking out all the ideas as soon as i can and ill report back

 

Correct. It was not my intention to imply that the Fuel Cut Solenoid did those other things. I was just using an already taken picture of mine to show the location of the FCS.


The federal carburetors are not the "feedback" type, but the California models are. Toyota even states that it uses a feedback carburetor in the FSM.

We (California) have the extra functions of the oxygen sensor, the Electronic Bleed Control Valve (EBCV) & the Electronic Air Control Valve (EACV). The last two will alter the air of the air/fuel mixture of the combustion via the emission computer. The EBCV does it upstream of the combustion chamber, in the carburetor, and the EACV does it after the combustion chamber, in the exhaust manifold.

 

I also figured out that the idle issue when the throttle wasnt sticking was caused by the egr valve. it was sticking which caused a vacuum leak. so i disconnected the vacuum lines from the egr and plugged them. now it runs perfect.

 

if the tank had some junk in it and it was real low it could have possibly picked up some junk on the bottom of the tank. kind of like a sink drain when it gets about empty it takes the junk down last. possibly have it in the carb somewhere now.

just a thought.

 

That's what I had thought happened originally. I went through and cleaned it but that didn't help. Because it was the egr valve.