37k miles on new engine, brand new carb,pvc valve, plugs, dist/rotor, air and fuel filter. The thing sucks gas! Can't figure out why, it was a factory rebuilt carb I put on it and it still gets crappy mileage, the same as before I put the new carb on it.

Every once in a while it will stutter, and then want to quit when I come to a stop. I give it a little gas to keep it revved up and it works fine for a while but will act up still. The timing is ok too.

One other thing...there are two green, round plugs on the left side of the engine (if you are facing it). One of them, the closest to the carb has a broken off wire. What do those plugs do? Could they affect mileage?

My first guess will be Ox sensor. And don't argue with me. Some carbed motors have them (mostly CA trucks). My 1982 did. It will be on the exhaust manifold with a one wire hookup.

...I second that. The O2 sensor can throw everything off.

Yep I see the o2. I didn't do anything about that because of the fact that it looks to have been replaced within the past few years with the header that was put on it. Plus...I think my carb is more of the culprit because it smells like its flooding.

Anyone know the recommended/stock float height level? I'm going to try to lower the float level and go from there, once again.

Agree with the above on O2 sensor.. My 2000 4Runner at 88K miles has dropped down about 3mpg below what it normally gets..

Stopped by the dealer to talk to my trusted service manager, SHE (highly unusual for a woman to be in this position), really knows her stuff.

Per her comments, at about 70 - 80k miles, mpg will start dropping due to the O2 sensor and they should be replaced.

Mine is on order and will pick it up Monday...

Recently I had a Ox sensor issue with my 85 22re. After installing a Thorley header about four or five years ago I had a harder and harder time passing smog tests. The engine was also not running right, and it wasn't pulling the idle vacuum it used to (13 inches, down from 16-17 inches). The Ox sensor had been replaced recently with OEM.

The Ox sensor reads off one tube on the Thorley header, and this is a common design. The exceptions are Downey which reads off two, and TRD which reads all four. After going round and round trying to get the truck to pass I had a sensor bung welded between the header and the cat, and installed a new screw-in heated Ox sensor. While there I also had them install a new cat. HC numbers at idle went from 1800 to 34. The motor runs signficantly better and vacuum is back up to 16 inches. While I'm sure the new cat is helping, I believe relocating the Ox sensor was the ticket to getting the motor to run correctly.

It was actually a mechanic that figured this out. He noticed that the Ox sensor was going cold at idle because only one tube was reading. The other alternative was to install a heated sensor on the header. While my solution involved more work and money I think it was the correct way to go.