I think the dizzy in my 390 is worn out, it seems to self adjust the timing like my 300 did when I was in highschool. I turned the advance to 8 (much less and it did not want to start) and it still will ping pulling grades when empty. sometimes it will even ping when accelerating away from the stop light. Sometimes it won't. I unhooked the vacuum advance sometime ago, I couln't hardly look at a slight hill without it pinging. I acquired this truck last fall and know nothing about its history. I don't know if anyone has had it apart for anything like hardened seats or such.

 

You may want to check the mechanical advanced under the point plate. They have a habit of sticking due to corrosion.

 

Make sure your cooling system is in top notch condition and is not causing some cylinders to get hotter than others. Is the engine original or has it been built? So w/ the initial timing set at 8, the engine bucks when cranking? You may have carbon build up in the cc. I just went through that w/ a 300 I6 about a month ago. Ran it at high rpms w/ a water/ATF mist down the intake and blew it out. Back to normal. And it would not start at all it would buck the starter so bad. It just slammed the cylinders. It just putts around campus so it doesn't get a good drive at all so it builds up carbon. It took me and my boss about 2 months to figure it out while working on other projects we had.

 

Check for a slipped vibration dampener which is giving you incorrect timing. TDC the #1 cylinder and see if the pointer is actually at 0°. If not the damper is bad.

 

Does cc stand for combustion chamber? Maybe I haven't had enough coffee yet this morning.

It doesn't buck when turning over, it acts like it isn't firing. Kind of rolls over real smooth like something is missing. Sometimes it acts normal and fires right up.

I didn't think of the damper having gone bad and not being lined up anymore. Will a damper off of a 360 work on it? Or should I just get a new one?

I don't think that it has been built, it still has the original 2bbl carb on it and exhaust manifolds. somebody did have the wrong thermostat in it. Did the FE's really have 2 different sized thermostats? I ended up having to run one out of a dodge to get one that had the larger diameter. Sure warms up better with the correct size thermo in it. Like I said, I know nothing about the history of this engine, I got the truck last fall from a nice lady who knew nothing about mechanical things.

 

cc mean cubic centimeters.

 

I meant it as combustion chamber, yes. For an engine that doesn't see alot of highway miles, it tends to build up carbon in the combustion chamber and causes hot spots which leads to detonation or pre-ignition. Sounds as though you have an intermittant ignition power problem. If it has points I'd throw a new set in there as they can come and go when their on their last leg. Just do a whole tune up to rule things out. I'm sure it wouldn't hurt it if it's been sitting a while. Anyways, I'd run some ATF down the intake very sparringly so that you don't hydro lock anything. If it's an original motor, then I'd bet there's a fair amount of buildup in the CC's and the tops of the pistons. Just an idea.

 

I just put points in it a week ago. Still the same thing. Could the coil be dying? I have been assuming that the dizzy is just shot and just needs rebuilt/replaced. I may try to drop some ATF down the carb to clean the "nasties" out of the "cc".

 

Did you change the condenser? They can cause all kinds of weird problems.

 

yes, I changed them as a unit for that reason.

 

Well if your dist shaft is worn enough, I suppose it could be grounding out when it runs around instead of your typical gap for the spark to jump. I know I had a camaro this happened on but rarely seen or heard of it. Only way to check is to pull the dist and wobble her around a bit.

 

HOw meny miles on the motor?, could it be a bad timing chain?

 

I have no idea how many miles are on it. I got it last fall, it was someone else's piece together project. It still pulls pretty strong, but it is tired.

 

You seem to have covered all the bases on the dizzy, it could be a lean run or timeing chain. some of the old fe,s had a cam gear that was alu with plastic teeth that gave a lot of strange problems.

 

What do you mean some? The vast majority had the plastic gears because they quieted the motor down without chain noise. I think they are just cheap crap.