how far do you have your idle screws backed out

Yes, fully warmed to operating temp is a must before you make adjustments. Cold oil makes the engine labor more at idle, cold fuel doesn't atomize well and cold cylinders don't seal well.

Devon

 

Yes, and also make sure engine is idling at or very near the specified RPM in neutral. (probably around 650-700) If it's idling too high, the centrifugal advance may be starting to come in the that will make it near impossible to get the idle right.

 

Sorry about being so frustrating but I can only give the info I have. The timing is at 10 drgrees advanced and yes I agree the distributer was changed at some point. I did the vacuum test last week and it pulled a consistant 18". I will try the idle screws again either tonight or on the weekend and be more thorough. The car is not on the road yet ( unless you call 500 ' test drives) but will be in a week or so where I will no better hopefully after a drive around and burning some of the old fuel.
Thanks for the help but instead of wasting peoples time right now I will try again for a little bit with the Cliff Ruggles book, or change to a holley.

 

Old fuel? How old??? You may be chasing your tail for all of this stuff for that reason alone!!!

Devon

 

eight month old fuel not much in tank but added about 5 galoons of new fuel to this. What can I tell you I bought the car last Nov and I am just at the point of putting it on the road now.

 

I agree totally with what DaWildcat has said and experienced bad fuel personally. I just bought a '71 GS455 this April that hadn't been driven for over two years. It had about 1/2 tank of old fuel in it (God knows what octane). When we got it off the trailer here in Orlando it ran like it had water in the gas. I just kept on driving it and adding good gas and it seems to run better and better as time goes by. When I first started driving it I replaced the plugs, points, condenser, wires, etc. and tweaked the carb because it wouldn't idle below about 1000 RPM. Long story short, I've had to continually turn the idle screw down each week until now, it idles at 750 and runs much more smoothly then before.

So, keep driving it and putting good hi test gas into the tank and perhaps even some Sta-Bil fuel stabilizer to absorb moisture. (either that or drain the tank). See if that helps before turning to other possibilities.

 

I saw in an earlier post that you were struggling to get any reponse from the idle screw adjustment. Classic vacuum leak symptom.

 

I don't think so as I am pulling 18". Some how the carb is getting gas through another source.

 

Strange thing again is that it will sit and idle quietly and once it warms up the revs jump up and it idles ( I am guessing at another 500 rpm's higher). I plan on looking at it again this weekend. I need to get it on the road so I can get it to a proper mechanic, but the local guy who is going to safety my car is busy till later next week

 

So, how is your car running now?

 

Same the screws are completely turned in and away she idles , runs fine as long as you don't give it a lot of gas. I have been pretty busy and it has been hotter than hall so I haven't really looked at it much. Thinking of getting the old carb rebuilt by a local guy and I can then 100% eliminate carb issues. Hoping its not a worn cam.

 

If you idle is high (above 1000 RPM), and the idle mix screws are completely tightened in, then you're feeding from the mains system. Check the carb for vacuum leaks when the engine is running. Spray carburetor cleaner around the base and the throttle linkage and see if you get an RPM increase.

I had a vacuum leak on my carburetor from the throttle shafts, even though I'd had the carb: "professionally," rebuilt with bushings and everything. Not all rebuilds are equal. The shop used the cheaper thin brass bushings instead of the oil-treated bronze bushings, and the shafts still leaked air.

 

I agree that the only place that it is being fed from is the mains, but its not only from idle that this happens , it also happens at any speed when i fully depress the pedal. which makes me think that it is the carb and not timing.

 

The timing is basic... it must, must , be right or the engine cannot be made to run right.... do the timing first , then adjust the carb after the engine is warmed up....

 

Well I pulled the hose off my vacuum advance and the car performs know different then when it is hooked up maybe even runs better , but for sure no better.

 

What is your idle RPM? Try lowering the RPM to get the main circuit to stop feeding the engine at idle.