Quote
yellowdog
I'm not trying to be a jerk here for my first post but you don't know what you are talking about. A vacuum canister is at maximum advance at idle and as the engine speed increases the vacuum decreases retarding the spark. The distributor has a centrifugal advance that increase with speed.
As for why the engine runs at start and then dies after cranking, if your truck has points and condenser then it has a start circuit that bypasses the white ceramic resistor on the firewall and provides a full 12 v to the coil. When the start circuit is released then the voltage runs through the resistor dropping the voltage down to 6 volts. I would check your wiring to the resistor and the see what the voltage is going in and coming out with a multitester. The next thing I would check would be the gap on the points and make sure they aren't pitted. If those are all checking out, and the points and condenser are new, then you might have a loose wire running from the resistor to the coil. If the resistor is not getting current then your wiring issue is between the ignition switch on the run circuit to the resistor.
I have also had a cracked cap do this, so check that next. One last place I would check is the plug wires themselves. when getting the full 12v it might run, but when it drops to 6 v it might start cutting out. You can check that at each plug by pulling the plug leave the plug wire and looking at the spark as it lays against a ground. check the spark off the coil high tension wire first, note the strength of the spark. now look at the individual, wires if the spark is weak or is not firing when you let off the starter then your wires are bad.
If you have electronic ignition then it could still be the resistor, the wiring or the plug wires.
You can run a separate wire through a new resistor straight to the battery and then to the coil to verify the ignition run circuit wiring or a bad resistor.
The fuel issue you mentioned about the filter not being full has nothing to do with being able to supply the fuel. I have a 65 mustang that uses a clear filter and when it runs the filter looks almost empty. I've let it fill up and reattached it but it still manages to drop back down looking empty. The proof is that the motor runs fine when starting. This is an electrical problem.

There's an old saying, "It's not what you say, it's how you say it..." Based on that, for your first post as quoted above, yes you may be a jerk or are being a jerk with your insulting choice of words. That is uncalled for. I hadn't seen it till I read it tonight.

Matter of fact, I do know what I'm talking about. However I don't consider your opinion of me or my mechanical or electrical knowledge to be worthy of consideration that I have to defend myself or trot out my resume', it isn't worth the effort. I and a few others here who know me are aware of my knowledge base and experience. It so happens that from time to time I make errors, I always have and always will. My memory isn't what it used to be and I have had certain medical problems occur which have effected it as well. However I do my best to help others where and how I can. I'll continue to do that as long as I live. Yes, contrary to the wishes of some, I will continue to post messages to this forum in that regard.

Regarding the vacuum advance cannister it doesn't really matter what exact nature of events cause it to function, or when and how vacuum occurs and for what reasons. What is important in the situation at hand is whether or not it is in fact working properly? Within that thought, a vacuum advance cannister failure, whether due to blown diaphragm, leaky hose or failed vacuum supply, failed connector pin or circlip at lever or whatever particular failure, will cause these exact symptoms as OP describes. It is the single most common cause of those exact symptoms as well. Therefore to blow that all off because my description of vacuum events was incorrect due to a memory error is to ignore and totally miss the most likely cause of this problem - the vacuum advance mechanism.

Easy way to test is to remove distributor cap, disconnect vacuum hose at carb or manifold and watch the points plate while sucking on the end of hose, to make sure it moves to maximum position. Also to hold tip of tongue on end of hose to plug it for a few moments to make sure it's not leaking.

Regarding your problem solving suggestions: A failed heat riser is not commonly known to kill an engine or entirely prevent it's running a few seconds after starting. It will affect performance but it will not commonly cause a no-start or a stall. In addition the leaking exhaust collector gaskets would further minimize the effects. A failed ballast resistor or ballast circuit is most commonly seen where the engine only starts and runs with key in 'Start' position and immediately dies when released to 'Run' position, which is not the case according to OP's post. A cracked distributor cap doesn't normally cause an engine to not run, or to stall seconds after starting. It most often causes erratic or uneven firing or poor performance due to carbon tracking at most. In addition this engine has a brand new distributor cap according to first post. It's not likely the sparkplug wires because this engine has brand new sparkplug wires according to first post.

Regarding your second post: an engine with stuck heat riser would not run perfectly for 2-3 seconds then quit immediately. A heat riser is designed to close thermostatically for a time while engine runs warming up, while also allowing some exhaust gases to bypass. Therefore even a stuck heat riser won't cause sufficient back pressure to stall the engine at startup because it isn't capable of completely sealing exhaust, plus that is the normal function at cold startup anyway!

There's no particular indication that the problem is electrical as you claim, by the description given. Regarding the choke, it starts and runs perfectly then suddenly dies. That doesn't sound like a choke problem. If choke is stuck closed it wouldn't cause a stall, because choke should be closed at cold startup. If it's stuck open it would not cause a stall when running perfectly as desribed. Smoke coming out of tailpipe and color of smoke, if there is any, hardly serves to diagnose this problem, as in so what? Regarding it being a possible points problem, that isn't at all likely because it runs perfectly for 2-3 seconds then suddenly stalls.