i'm not saying i have women figured out; i certainly don't. What i'm saying is that based on my history, i have an easier time getting someone to go to bed than fixing cars. And that's saying something......Figuring out a carburetor problem is a lot easier then trying to understand women and there problems. Been married 21 years and still can't figure things out with my other half at times lol. Keep working at it and don't give up. Its times like this that it will give you a heck of a lot more experience and in future times when problems arise you will be able to figure them out a lot easier and tune even better.
Trust me when I was 18 years old I did not know even how to adjust the idle on a carburetor let alone troubleshoot one. I only knew how to check and fill fluids and that was it. It took me a lot of years and reading and experience and to a lot of folks helping me on here that has led me to where I am now.
Thanks. However, wouldn't the ability to idle at 1000 or above [if i keep my foot on the gas or if the carb is on hi-step /choke still engaged, (assuming i can manage to get it started at all at this point...)] indefinitely indicate that is is likely NOT fuel or spark that's the problem?It really sounds like either fuel pump or ignition.
Most common to worn throttle shafts is you cannot get the idle speed down unless you cut off the fuel flow as it is getting sufficient air around the shafts. Given new Q-Jets haven’t been made since dinosaurs roomed the earth your unit is most likely a rebuild so unless it was a shop that bushes the throttle shaft bore it is as old as the carburetor was newly made.
I’ve had carburetors that just died, never could find the cause, repetitive cleaning, micro inspection and kit rebuilding never exposed or improved the problem. Replacing the carburetor solved the problem immediately so it wasn’t fuel delivery, ignition or cam ot it’s timing set problem. Of those that did this they were Holley’s and Q-Jets, I can’t remember a Carter now Edelbrock, or Ford 2100 or 4100 series doing this. That said a long time ago a woman I was dating had an early 1980’s Ford station wagon that every now and and then would just stop running when sitting out a traffic light. It had fuel and spark but would not run till it sat for a few minutes then it would fire up and run fine till next time. She traded it for a Honda. So some of these problems are essentially unsolvable, in the case of the Ford in question, hours of inspection in the shop where of course it was running never exposed the problem. You would need the shops resources with you at a traffic light when it quit. By the time you had it towed to the shop, it would start up by simply turning the key on start and away it would go. So it’s hard to fault find when the fault isn’t displaying.
Now back at your problem with a time element for recovery, this speaks strongly to fuel supply and or ignition. This would include tank venting and weird things like some object being drawn into the fuel pick up which could range from a cigarette filter in the tank to a flex line that the interior has a peeling surface that reduces to cuts off fuel flow to where once the forces are removed eventually corrects itself. A pressure test with observation when this happens may reveal this. Idling with a functional hot spot under the plenum might cook the fuel out of the bowl flooding the engine and requiring a cool down and cylinder venting to get a restart.
This also fits a heat sensitive ignition module and or the timing sensor if your distributor separates these functions.
Oily spark plugs do not dry out but fuel wet plugs do.
A common SBC vacuum leak which includes making oily spark plugs is the intake gasket leaking on the valley side so it is not visible. This is really common where the block has been decked, or the heads milled, or aftermarket parts of head’s and intake are used where fitments, machined angles, and tolerances stack to allow gaps in sealing the intake to the head’s. Another common one
especially where screw in rocker studs are used is vacuum leaks into the ports around the threads of the studs. Valve guide to stem clearance is another problem especially with bronze guides.
Can you give me a little more detail on how to do the spark check thing: You said remove plug wire. Does this mean with no spark plug etc.?bypass the fuel in the tank, either gravity feed the carb or put supply to pump in some fresh fuel. Remove a plug wire and lay it on the engine, spark should easily jump an inch or more. Check voltage at the distributor with key on and while cranking.
1) i don't think the engine is flooding while it's running. Of course i don't know what the hell i'm doing, so it could be. But my hunch is no.is the engine flooding while running?
Do you see lots of fuel leaving the booster?
Either the fuel is bad or there is too much of it.
You said it won't hit on ether? Flooding seems likely.
East coast---DC/Balto.DB Where are you located!?
I still think need to start with simple basics, compression, spark and fuel.
Like others have said a simple gravity tank.