is your ignition box hooked up to a keyed 12volt source? It might just be that it's hooked to an on all the time source and all it needs to go is the crank and when you do it gets stuck on. Make sure the box is properly connected to a switched 12v source so when the key is on the box is on.
Seems simple but It's hard to tell without knowing how everything is wired up.
EDIT: Keep in mind that an ignition box draws power from the battery/alternator BUT it needs a trigger from a keyed 12v source. It works like a relay basically.
Seems simple but It's hard to tell without knowing how everything is wired up.
EDIT: Keep in mind that an ignition box draws power from the battery/alternator BUT it needs a trigger from a keyed 12v source. It works like a relay basically.
You most certainly can stall the motor with an auto. How do I know? Mine used to do it as well, so rather than shut it off in park and let it diesel, I started shutting it off in drive and it killed it instantly with no run-on. My problem was the carbs were too rich, once I fixed that, it fixed the problem.
The best answers, more knock resistant fuel and/or removal of hot spots.
Dieseling is caused by hot spots (Usually carbon) and compression, the higher the compression (or hotter the engine) the 'fewer' hot spots needed.
My knee jerk response is to just get a jug of TEL ... Yeah, Right, I've been looking for years.
Well, there are actually a few more things that can contribute to or even cause runon
* Idle speed too high--this is why there were idle solenoids on some cars that did not have A/C
* Ignition timing too far advanced
As has already been mentioned, carbon building can cause this condition, because it can create a "hot spot" that basically acts like a glow plug, and ignites the fuel even when the spark plug isn't firing.
One "old school" way we used to remove carbon is to take a quart of water, and with the engine running at around 2000 RPM, pour it down through the carburetor; what this will do is basically "steam clean" the piston tops, because the water will instantly turn to steam and blast the carbon away.
I've also used Transmission fluid as well--and it's effective, but man, it really smokes up the place when you do that! Because of that, whenever I'm faced with removing carbon, I just use water these days.
So . . . if you have a stock or smooth idle camshaft, make sure that the idle speed is set to the shop manual specs--and if it has an idle solenoid, use that to adjust the speed, not the screw on the throttle blades.
With an idle solenoid that engages when you turn on the key (no A/C), the screw that adjusts the throttle blades should be set so that the engine just barely runs when it's at full operating temperature, and the idle solenoid is then used to adjust the idle speed to the specifications published in the manual.
If you have an aftermarket long duration camshaft, try to get it to idle as slowly as possible.
In either case, after you set the idle speed, you will probably want to make sure your timing is set to the correct specs as well--if you have to move it back, you'll also need to adjust the timing again (and repeat the idle speed adjustment . . .)
Then--I'd recommend the "water treatment" to remove any carbon on the tops of the pistons or in the combustion chambers. It certainly won't hurt anything if carbon buildup is minimal, and it could go a long way toward removing any that exists.
I wouldn't it may be old school and all....but if you do that little trick the wrong way you could bend a rod or worse. Water doesn't compress.
That's a good point there, and I should have been more descriptive with the details of how to do this . . . if you're not familiar with how to do it, it might not work out too well.
But--if you pour a little bit of the water at a time (a small stream), with the engine at a very high idle (like around the 2000RPM I mentioned in my previous post), you shouldn't have any problems--I never have.
One more tip--when pouring the water down through the carb, hold the container is such a way that if water comes out too quickly, it will go onto the engine instead of going into it. For example, leaning across the driver's fender, point the container away from you and pour into the venturi on the passenger side.
And cars with AC had 2 stage solenoids.
I'm trying to remember a car with a solenoid before unleaded fuel, only thing I know I saw was a dashpot.
Or retarded. Both lead to excess engine heat.
It's been mentioned how an engine can hydrolock if the water is applied to quickly.
A quart in at least a 5 minute period, 10 minutes would be better.
We use to set timing by going to a "country road", do acceleration runs at WOT in a higher gear and keep bumping the timing up till the engine pinged, and when it pinged back it off a hair.*
But then stock ford had funny chains and plastic cam gears ....
{edit} * Forgot to say, we use to check our main jets during these acceleration runs by shutting off the key while keeping the throttle open then reading the plugs. {/edit}
I figured the engine was 'fresh', I figured it wouldn't have more than fluffy carbon from, say, idling rich.
Things I left out about hot spots, any kind of a raised edge in the combustion chamber can result in a hot spot. Way back when there were tails of detonation traced back to casting flash.
Worn valves will also lead to dieseling, knife edging or insuficent seat can lead to a glowing valve. At 6,000 miles that shouldn't be the problem.
There is an obvious answer, Your running too hot of a plug. Drop down a heat range or two. If you drop 2 ranges and the problem goes away you have nailed the problem, then you only have to find the right heat range in the right plug manufacturer. I'm sitting here laughing at my losing track of the number of sets of plugs I had laying around.
(plugs are like shoes, size 11B from one manufacturer is a 10EE from another, and just cause they look the same doesn't make them the same).
Idle or main jet?
Concern yourself only with the idle circuit.
Seems to me the most interesting things happen in #s 4 (and 8).
Thing is soon as the engine is ran up the fluffy carbon from idle should be gone (except for maybe the deepest recesses of the insulator).
If I were you my next move would be to set the timing where it's "suppose to be" and install a colder plug and see what happens.