Q-Jet

[Overhaulin]

Okay I recently bought  a 73 Firebird 455 car. The previous owner had rebuilt the engine (stock) and the carb. I noticed the engine was idling high at about 1000 RPM. When I got it home the first thing I did was put a timing light on it and not to my surprise the timing was way off... I was surprised it ran at all.

So I got the timing right and proceeded to adjust idle mixture screws on my stock Q-Jet. I seated the screws then turned them back out 2 and half turns. It still idled a little rough and a little high. I played with the mixture screws and the idle speed until I realized that I had backed the idle screw off so far it was not even touching the throttle shaft and the engine was running on idle screw adjustment only. Help!

Thanks in advance for any help.

[Cliff Ruggles]

It's getting air someplace.  Vacuum leak or throttle plates not fully closing.....Cliff

[Overhaulin]

Thanks Cliff.

Do you publish a tuning book?

[Cliff Ruggles]

I haven't published a book specifically on tuning, but we talk about both carburetor and distributor tuning in our Q-jet book.....Cliff