So I've been trying to figure out a carb problem on my Automatic 1985 Toyota Pickup with a stock carb on a 22R. I rebuilt the carb a few months back, but stumbling and stalling continues... (Hold your suggestions for a Weber please, that'll be my last resort for now)

So I'll start the engine cold and it will 100% of the time die after a second, and I'll have to start again. If I touch the throttle at all, dies, usually happens 2-4 times before I can get moving even after warming up 10-15 min. Once I get going, If I come to a stop, once I hit the throttle it's likely to cut the engine 2 out of 3 times. I can usually hit the gas very slowly or very quickly and that seems to help, but still not a solid pattern that I can see. Once I get up to operating temp, this all seems to be ok, although still some stumbling on throttle from complete stop. Sometimes it still stalls out at operating temp.

What I've tried:
-Tested EGR valve by simply disconnecting and driving around the block, didn't seem to make a diff.

-Replaced rotor cap and rotor arm and cleaned and gapped spark plugs just to make sure it was unrelated, snappier but no difference for the carb problem.

-Thinking it has to do with one of the circuits (float, Main Jet, Idling, etc...) But a strong suspicion on the Progression Circuit since that is where the carb goes from Idle to Main Jet operation. I've read in my Chilton's that the hoses are easily clogged and may create "flat spots" in acceleration, which sounds like what I've got going on, except that I did a full carb dip when I rebuilt it. Could it be external hoses?

Any other thoughts or ways to continue trouble shooting would be great! Thanks!

 

 

Yes, actually. After a lot of head scratching and money spent, it was the simplest problem ever (isn't that how it goes?). Vacuums leak. Nothing to do with the carburetor. You can probe around your hoses with a propane torch while the engine is running. If there is a vacuum leak, it will suck the fuel in and revv for a moment. Vacuum tubing is so cheap, it may well be worth just switching out all of your vacuum lines and see if that helps.

 

Nice. Did you find the actual leaking hose and if so which one was it?

 

The Grits: I applaud you for sticking to your guns about not converting to a Weber to solve your problem. I tried to solve my stumbling 22R issues by replacing all of the vacuum hoses, but stopped short of rebuilding the carburetor due to my own limited resources and experience. Unfortunately, every mechanic I spoke too talked Weber so I finally caved. I have regretted this move ever since because I lost all of the original EGR system functionality. I understand that it is possible to reverse the Weber installation process, Might look into this summer. Any suggestions would be appreciated.