My engine has got the ADHD!, Can't get my engine to idle at less that 1000 Options

[tornik550]

On my dual weber 44idf, 2258 engine- I cannot get my engine to idle at less than 1000 rpm. I have backed out both idle speed screws all the way. I unhooked the linkage. I played with the timing (which will slow it however it runs like crap). I adjusted the mixture. I even put new throttle plates in the carbs and synced them. I made sure the throttle shafts were not bent.

My old throttle plates were worn which I feel let too much air in. I replaced the plates with new ones which I thought would correct the problem. I was able to get the idle to go down from 1200 to 1000. I shined a light under the plate after installing them- I can see a very slight amount of light from between the plate and barrel wall.


Any ideas?

[tornik550]

Thank you to everyone for your ideas. The past two nights, I have been trying to get my throttle plates to line up perfectly. As I mentioned, they are brand new and they appear to line up perfect however if you shine a bright light behind them, there is an extremely fine line between the butterfly and barrel. I have an extra set of new throttle plates so I decided to try to shape the plates better to make them so they would close completely.

It took a very long time of tedious trial and error sanding and checking my work by sticking a shop vac in one end of the barrel and putting a snail gauge in the other. Once I was able minimal readings (1.5 or less) on both barrels, my work was done. I installed them and now the car runs great. I am able to get the engine to idle as low as I want. If I back the idle speed screws all the way out, the engine will stall. Guess that was my problem.