Not sure which word to exactly discribe it by. (6/9/13) After my last fail, I had my carb rebuilt and tuned, and ask the re-builders to set it up to have a better chance to pass smog. Unfortunately, I think they overly leaned out the carb. With the engine running, it sputters slightly, and the fuel in the bowl is below the bottom mark. When i rev the engine over 2k rpms, it beginnings to sputter more, and the revs decrease. I checked the plugs, they are in the good range, and maybe going to the lean rnage.

I did some more work (6/17/13)

I still have my problem. I adjusted the carb's float, it is now between the bottom and top notches in the float bowel. At idle, it feels like it has a missfire, it doesn't feel smooth. Not really rough either, since according to the tach needle it is constant and strong. Revving the engine, from 1k to 2k, ti revs fine. 2K and above(though mainly between 2k and 2.5k) it does the same miss tendency. For example, say if i rev the engine to 2.5k rpm, and hold it, the rpms will fluctuate, go down, then trying to go back up to maintain. even if it does go back to 2.5rpms, it will still fluctuate.

The plugs are a year old. The rotors is maybe 6 months old. The rotors also shows no signs of damage, same with the rotors cap. I changed spark plug wires to the originals my car had, and noticed the missing worsened. The wires I am running currently I found in good 'looking' condition at the pick a part. it could be my problem. However, The car never ran like this before with the wires.

The only part that has changed in any way since when it was running fine till now was the carburetor rebuild. Either the wires'went bad(though unlikely) while the car was sitting, or I am looking at the work system. I also don't want to start throwing money at it till I have a good idea on where to focus.

Could it be the 91 grade fuel I am running in it? Before, I only used 87.

I have the timing at the correct degree, how would I go about adjusting the fuel mixture? I thought(mine being a stock carb) the computer controls that via the solenoids. I do understand that the fuel adjustment screw at the base only controls the idle and 1/4 throttle fuel mixture.

Bumping this, made a video

http://youtu.be/DkO2227CVLY

bass sound warning. However, te sound to listen for is the 'popping' sound. Also, when i reenter the car, notice how the tachometer moves up and down while a I rev. The popping noises are present at idle(slightly) and between 2k and 3k rpms. Fuel, ignition?

bump, anyone have any ideas?

gonna give this a bump and update. I replaced the wires with new denso wires, and i still have the same problem. The cars sputters while revving, and pops at idle. Maybe its a fuel problem(either carb tuning or octane). New fuel filter btw. As i said before, i don't remember the car doing this at all before having the carb being rebuilt and adjusted to run lean(the spark plugs do confirm the car is running lean) tomorrow i'll do a number of tests, maybe i messed up the engine some where. Maybe I should try to rich-en the car up a bit?

update. I'm going to have to tear into the engine

compression:
cylinder 1 110-120
cylinder 2 140ish
cylinder 3 155
cylinder 4 135

burnt valve probly, I'll have to get it machined

vaccum at idle is between 15-17, since the needle twitches.

bump?

adjust the carb....how did you decide it was burnt valve....from compression?

You know, I should bump this. I did a leak down test, if anything, i have a large amount of leaking in the rings. I'm not sure if its because they did not seat, haven't seated yet,(I am seeing leaking range from 43% to 35%, the engine maybe has 3 miles on it) or are fubard. Also, some cylinders will leak into each other, like 1 leaks into 2. yet, when doing the test on two, it did not leak back. I could use some advice before I do anything drastic. I got a better vacuum reading at the base of the carb, and it holds a fairly steady 18 inches. sometimes it will go 17, and the needle twitches ever so slightly, yet it does not fluctuate to a different number. /after a readjust of the valves, the popping at idle is almost gone. I am tempted to try seafoam or marvel mystery oil, good be some gunk on the valves and rocker assembly giving me trouble.

However, i am more worried about the compression and leakage numbers.