Dinoplex with excess of personality.

[Barnfind]

Hello.

I'm new in this forum, I recently purchased a 2400 coupe, stopped for some years, and the first issue to come across is the dinoplex unit, which behaves in a quite particular way. With key turned on, but no start, I can clearly listen to high frequency sparks. If I pop out one of the cables and leave it hanging on the breeze, I can clearly see sparks all around.
I have removed the distributor, checked the centrifugal advances (not the problem, but one thing less to check), set the contacts to 0.3mm (I don't know what the correct gap is), did not check the condenser, I did not have the correct equipment for test.
The car starts, with some coughs, and nice backfires, but does not rev, which makes me think that the spark does not follow the engine speed even running. I mean, I have the same spark running or not. I know it sounds weird, but..

Any idea would be greatly appreciated.

Thanks in advance

[alh]

Sounds like the thryristor THR1 is broken, maybe also the avalanche diode D5. Replacing THR1 has a good chance to get rid of this problem.

http://dinoplex.org/#Dinoplex_AEC101

Good luck,
Adrian

[Barnfind]

I have printed all the info from dinoplex.org, tomorrow I will do some testing.

Thanks a lot..

[Barnfind]

Update:

After cleaning cap and wires (def not the reason) and adjusting contacts gap to 0.3mm, it has stopped to spark witn engine stopped. It starts fine with choke, but still backfires hard sometimes. Anyway, I have done nothing to it but turn the key on!!

So time to start with the carbs.

Thanks!

[Stefan2000]

Your sure that at least ignition timing is spot on?
By changing the contact breaker gap you also change the timing position and with these dual point breakers also the relation of interdependent degrees between one bank and the other bank. I would check and make sure this is correct in first place, if my memory serves me well you can use a timing light at cylinder 3 for right bank position and cylinder 4 for left bank position or the other way around.
Gap should be 0.35mm

[Barnfind]

Thanks Stefan.

No, the timing is not spot on. It is barely at place, becouse I was lacking some information.
Yes, gap should be 0.32-0.38.
I still need to know which mark on the plate (there are 2) should use for correct timing, and what does each mean. I also need to change the cables, as they look really old, and that won't help a lot...

Is there any procedure to follow for the distribitor timing? The only thing I have found is for the 246, with twin contacts, 6 lobe, but I haven't found any references for the marks to use..

Thanks..

[Stefan2000]

I have to type this by heart because im not next to my car now so correct me if i'm wrong.
What you have to do is look at the timing mark at the pulley (which is running the v-belt) and the timing marks on the engine. See what rotational direction the engine is running while you crank it over. There is one mark on the pulley and 2 on the engine. One mark on the engine indicates pistons top dead center, the other mark on the engine indicates the point which you have to use for your static ignition advanced timing. It is ignition advance so it means that this point is some 6 to 10 degrees before top dead center, this means that if you rotate the engine in the right rotational direction the first mark you will meet is the one for your static ignition setting and the second is top dead center.
The engine should fire at this static timing mark at cylinder number 3 while running idle so attach a timing light to cylinder number 3 fire up the engine and check if this is correct.
Now cylinder number 4 fires exactly 360 crankshaft degrees after cylinder number 3 so also attach timing light to cylinder 4 and double-check. If timing between cylinder 3 and 4 is a couple degrees different this means that you have to rotate and adjust the base setting of 1 of the 2 contact breakers (2 screws connecting the breaker to the distributor housing)
If you don't have a timing light things will become a bit complicated, you can get the base setting right with a light bulb but it would only be a method i would use if i was lost somewhere in the dessert without having any other option.

[Barnfind]

Thanks again Stefan.

I have ben posting by heart, instead of taking my time with the engine. There is one mark in the damper (I have only seen one), and 2 on the plate, one for PM (may be -4, which is also stamped on it), and another for 10. (I found out after a good cleaning)

My strobe doesn't like the Dino engine, it refuses to work even with known good cables. I will need to wait for the new ones to arrive. But to start with I will do the timing light method. That will keep the engine in a more or less safe position and it is a reasonable good point to start.

I will post any news.

Regards, and thanks again.