Idle problem - Toyota Nation Forum : Toyota Car and Truck Forums

shadowsun · 09-25-2005, 05:07 PM

Does anyone know what would cause a carburetor to occasionally not fall into idle, but to fall into not running at all every now and then?

The engine dies so quietly i don't even notice it unless I'm looking at the tach. Also, the tach doesn't seem to be entirely accurate right now.

Any clues would be appreciated. :/

crockdaddy420 · 09-26-2005, 01:52 PM

Dirty carb possibly, worth a shot to clean it, real easy.

shadowsun · 09-26-2005, 10:17 PM

Oi. Have rebuilt the carburetor twice this month, once to clean it and replace the float assembly, once to fix some hoses and just for kicks. Carburetor is clean. Runs rich as hell no matter what i seem to do with it, but clean.

I think the problem is that the higher the RPM, the richer the carb runs.. if I run the car hard at all (i.e. hitting 4kRPM even) for more then a minute or two, the engine will flood instead of idle.

One of the reasons I want to replace the stock carb, I'm constantly being told it's shit, and constantly being told to leave it on instead of replacing it with a mikuyi or a weber or such... Not really understanding why I'm picking up conflicting information in different places yet. Trying to decipher this.

Excidium · 09-27-2005, 07:41 AM

Check your choke.

shadowsun · 09-27-2005, 02:03 PM

The choke, so near as I can tell, is fine. That's the upper butterfly plate in the larger carb barrel, right?

Flashmn · 09-27-2005, 03:05 PM

Yes. Check that the needle valve is working in the float chamber.

shadowsun · 09-27-2005, 05:17 PM

Needle valve is working fine, I replaced the entire assy sans float and tested/recalibrated it.

tashirosgt · 09-27-2005, 05:26 PM

Does the "Gen4" refer to the 1979 model? I had one but never worked on it myself. I do remember mechanics describing a carb problem caused by a tube that brought heat from the exhaust up to the carburetor. The tube would get corroded through and dirt and exhaust would be blown into the car. Since you cleaned yours so well, this is probably not your problem. But I would like know if there really is such a tube. ( On mine, the throttle would begin sticking and I once took my foot off the accelerator to take an exit off the freeway and the car didn't slow down at all !)

shadowsun · 09-28-2005, 01:26 AM

In my case, it's referring to the 1982 model with the 3TC engine. And yes, there is such a tube, it's part of emissions shit. Called the EGR, or Exhaust Gas (recycler,reuptake,reducer,etc).

Most of my tube is gone, but the valve is disconnected afaict, so I've been mostly ignoring this. Especially since the tube was fubar before I had problems.

imho, the only use for it would be a homebrew jake brake