Thread: Timing and Idle trouble

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Hello! Im new to posting on this site but have found it very useful thus and far, but im finally stumped.

I have to admit right now im the most engine savy but am generally mechanicilly inclined.

So to my question.

I have a 350 small block in my pickup with a standard Rochester Quadrajet in it (sad i know but funds are a tad lacking) and it has been having trouble with stumbling and just bad gas milage as of late. I thought it was the carb and had it rebuilt by a friend has rebuilt carbs like this for years. It helped but didnt entirely fix the problem. I put new plugs and wires in which were generally pretty messed and needed changing anyway, and that didnt help either. Ive messed with the idle and mixture setting and think i have narrowed it down.

With the mixture screws turned allt he way in the engine still runs strong and when i mess with the idle screw i have to litterally pull it all the way out to get it stumble a little bit. So im thinking it may be a timing issue. If not i fear they may be something much worse wrong. Im not pretending to know what im doing i just need help

I still think you have carb trouble....

When you turn the idle screws all the way in it should die...

Check your plugs...what color are they...black? sounds like it's flooding a little ....Improper float setting? too much fuel pressure...

Look down the carb while it's running do you see it dripping or puddle-ing fuel on the plates?

To correctly set the idle-mixture screws... set the idle around 600 rpm and hook a vaccum guage to the carb on a full time vacuum port ( on a Q-jet I use the front choke pull-off port)

Then you adjust each screw ( one at a time) until you recieve the HIGHEST vacuum reading on the gauge.... after you do this NEVER TOUCH THEM AGAIN!

First thing people do when trying to cure a carb problem is mess with the bleed screws and sometimes create more problems....