uh, for some reason the vacume advance canister on my distributor advances my timeing to roughly 18 degrees from zero (i cant tell because it goes so far off the timeing mark). so i figure to compensate, cant i just retard the timeing by rotating the distributor to around 8 degrees? i actualy tryed it and it seemed to run good, but the next morning it wouldnt hold a steady idle and the rpm's kept slowly droping from 1000 to around 250 where it would have died if i didnt give it some gas. its never done this before. later on in the day after driving it to work like this, it returned to normal (sort of steady 1000 at idle), but the rpms were going up and down all the time. i also re-adjusted the idle mixture screws to maximize the rpms (by what the edelbrock manual says), and lowered the fuel pressure to around 4 1/2 psi (was 5). i know there is adjustable vacume advances out there that i can swap into my distributor, but first i just want to gather some information about this. also, when i gunned it down a straight stretch of road, it sounded like it was backfireing, i kept hearing some kind of poping noise like cars sometimes make when "slowing down". while doing this the rpms were not steady and the car was slightly surgeing, but only slightly. the car sounds alright, but still, this bugs me. any ideas?

 

You don't want to compensate for the vacuum advance, it's supposed to do that. You've retarded the timing way too far. Set the timing with the vacuum advance disconnected and the vacuum line plugged.

 

so is it bad to be flooring it with this set up like that? whats the worst that can happen or has happend?

 

actualy, now that i think about it, i have a few more questions, what exactly is the point of advanceing timeing? what is the most either way you can set the timeing before the car will not run properly, how far can/should i advance the timeing? i want good fuel milage mostly, but decent power. basicaly i just want the ideal setting for my engine that will be best for all situations and give it the longest life span. this car is my daily driver

 

Sounds like you have the vacuum advance hooked to manifold vacuum--should be ported vacuum. Hooked to ported vacuum the vacuum advance won't advance at idle at all. The 'point' of ignition advance is that as the engine runs faster the spark in the cylinder needs to fire before the piston is all the way up--because it takes time to get the spark to the plug, fire it, and burn the fuel. Among other things, having alot of advance at idle can make it hard to start. The point of vacuum advance is to add some timing at 'normal' throttle--helps keep the plugs clean and fuel mileage. Sounds like you have been playing with the advance--no exact advance we can tell you is going to work the best in your car. Lots of things affect the timing your engine 'needs' to be efficient. Put it back to stock specs and start over. Make small adjustments and see if it helps. Keep in mind that the wrong timing can break stuff