RotorMotorDriver

iTrader: (1)

Ok, so the other day I decided to try and figure out what the infernal ticking (arcing) is that I hear from the trailing ignition inside my dizzy is. Its just a very faint constant ticking inside the dizzy with the trailing ignition (if I unplug the trailing ignition, it stops). I thought maybe its just the spark jumping all the damn air gaps, but just to be safe, I thought I would investigate inside there. I took the cap, rotor, and dust shield off, and got to looking at how nasty and dirty is in there, so I decided to clean it out some. I took the whole distributor out and got to messing with the advance mechanisims and found out that the trailing advance mechanisim wasnt even moving. I thought maybe it had something to do with the fact that it needed vacuum (even though I was sure this wasnt the case). So I hooked up my trusty hand vacuum pump, and whatdaya know, nadda. The diaphragm in the trailing advance vacuum pot thingy is shot, so the entire time Ive had this car (from the look of it in there), the trailing ignition has never been advancing. Even thought I dont use the vacuum advance anymore, I still thought that maybe the centrifugal advance needed to work, and I figured that it probably wasnt moving either. So, I got in there and cleaned for quite the while and finally got the mechanisims (both of them) moving freely with no more rought spots and what have you. I re-assembled it all, and started the car. I decided that since I had this all apart I might as well re-set the timing as well, so I got out the timing light and went to set the timing when it occured to me I wasnt sure where to put it, lol. The manual says to set it at the marks at 750 RPMS. Well, with the Weber, it doesnt like to idle that low (it will, just not that smooth). I can get a perfectly smooth idle as low at 800, but for ease of driving in the morning and what not, its set to ~850-900 RPMs. So, since the engine is idling higher than "normal", the timing marks are in different places. I just set the idle on the carb to 750, set the timing, and turned the idle back up, but how should it be set? I know I need to mark my pulley ala Paul Yaw so I can actually set the timing, but I havent gotten around to it yet.

So, to summarize, here are the questions that were supposed to be asked (whether they were or not Im not sure...lol)

1. Should I replace the vacuum diaphragm even though Im only using the centrifugal advance, or should I just be ok now that its actually moving ok?

2. How big of a deal is it that the trailing hasnt been moving all this time? I didnt feel or notice any difference in anything now that its been cleaned?

3. Anyone have any tips or whatever for setting the timing "right", or should I just do the pulley marking thing and do it that way?

4. If I do the pulley marking, what should I set the timing to?

~T.J.

specRX7_22

how big of a deal is it that the trailing was never advancing? id say its a pretty big deal. if the trailing spark was never advancing, then it's been firing way too late. even though the trailing spark isnt as important as the leading spark, i would think you would've felt a difference. maybe not if your just puttin around town, but you should definately feel a difference when you get on it, i would think.

RotorMotorDriver

iTrader: (1)

Well, I thought that it would make a difference as well, but it honestly doesnt seem to have anywhere in the RPMs, and odly enough, it almost seems as if my gas mileage has gone DOWN since I fixed it ? Im thinking about implimenting the DLIDFIS system soon though (probably later tonight), so if there are any other problems, I will probably find out soon enough, lol.

~T.J.

RotorMotorDriver

iTrader: (1)

Well ****, I did the DLIDFIS, but its running for **** and I cant for the life of me figure out why. Ive swapped ignitors, checked and rechecked wiring, checked spark, everything I can think of, and it just wont run right. Its loping and hunting at "idle" and just sounds like its gonna die anytime I try and drive it anywhere. I have spark on all the coils and plugs though...Maybe timing still?

~T.J.

RotorMotorDriver

iTrader: (1)

Bump...

~T.J.

Northern 7

iTrader: (3)

I'm a little confused by this post - have you set up timing at least to the stock marks? If your leading is off, especially retarded, you idle will suck - it will idle low and rough as though it's not even firing on the lead. You can set the timing with your idle at 800 or 900 to at least give you an idea if that is the problem. One other thing, I'm not running direct fire, duel ignitor but I am running a MSD in direct fire - I had a bad connection at the cap for of one of the signal wires in the harness that runs to the cap - that caused the same symptoms you are describing - crappy idle and felt like it would die unless you kept the rev's up (and the rev's were very laboured) - I would double check for a clean connection. Hopefully one of the duel ignitor guys will chime in on this..

Jeff20B

iTrader: (13)

Glad you got it working.

REVHED

1. The linkages conncected to the advance pots are used purely for vacuum advance and for adjusting the trailing ignition timing. They have nothing to do with the centrifugal advance.

The centrifugal advance works by rotating the top part of the dizzy shaft where the reluctor sits seperate to the bottom of the shaft which is geared to the engine. This changes the reluctors position in relation to the pickups and changes the timing. If you twist the reluctor by hand you will notice it has some rotational play in it. That's the centrifugal advance.

So in other words, if you're not using the vacuum advance then there's no reason to worry about the pot or even the linkages as long as the initial timing is set correctly.

Let me know if any if that doesn't make sense.

2. See above.

3. By far the best way is to accurately mark the pulley and set the timing at about 3000rpm so the full mechanical advance is dialled in.

4. Best results seem to come from about 15 to 16* trailing and 24 to 25* leading.

RotorMotorDriver

iTrader: (1)

That makes sense, thanks REVHED. I was just concerned because the rotating assembly wasnt rotating at all. Oh well, at least the car runs now. I guess later when I have some more spare time (I have lots of time, Im just lazy ), Ill go mark my pulley properly and set the timing right .

~T.J.

Jeff20B

iTrader: (13)

Marking pullies is fun! I use a cloth tape measure with metric and english scales on it. The metric one works perfectly because the pulley is 360mm and one mm is equal to one degree. It was accurate enough to mark a pulley for setting up my 20B modded FB dizzy.

Make a permanent mark with a small trangle file and then dab some white out or whatever in there so it'll show up easily with a timing light.

RotorMotorDriver

iTrader: (1)

Never thought of white out, good idea!

~T.J.