C2 alternator problems.....

[kevin m. nelson]

i have a 1966 425 coupe. when i try to start it, it fires right up. then on its' own almost dies, then returns to idle, but not before backfiring through the secondaries and of course a little flame appears. we've noticed that every time this happens, you can see a little sparking coming from the back of the alternator by one of the diodes. my question is can i try putting a non-t.i. alternator on the car to see if this is the cause of my starting problems before i commit to rebuilding my t.i. alternator, which by the way is brand new ? the timing and the valves are set correctly. i figure that the sparking of the alternator doide is causing some sort of electrical surge and causing the backfire. am i close with my diagnosis ? will the installation of a non-t.i. alternator just to see if it solves the problem ruin anything ?
thanks,

kevin

[Joe L.]

Re: C2 alternator problems.....

Kevin-----

First of all, I would be absolutely amazed if your alternator problem has anything, at all, to do with your other problems. The converse may be true, though.

If you want to rule out the alternator, you can install any other compatible alternator. It does not have to be a "TI alternator". There is nothing special, at all, about a "TI alternator". It's just that many TI applications were originally fitted with an alternator of higher amperage capacity than non-TI-equipped cars. That's the only difference. For a short term test situation, you can install any other DN-series alternator of 37 or greater amp output. It will have no negative consequences for a short term test situation. It might even work ok in the long term, but I would not recommend it.

[kevin m. nelson]

Re: C2 alternator problems.....

hey joe,

i'll try the non-t.i. alt. tomorrow. if you don't think that's what's causing my backfiring prob, what do you suggest. like i stated, the timing and the valves are set perfectly. the carb was just completely gone through by a very reputable rebuilder and completely rebuilt down to the correct n.c.r.s. finishes on all the pieces.the heads have just been done also.i might add the car has documented 54K original miles and is a frame-on restored #2 plus condition coupe.i'll keep you posted as to what the alternator swap proves tomorrow.
thanks,

kevin

[John H.]

Re: C2 alternator problems.....

Backfires are normally related to a momentary overly-lean condition; I'd check out the choke mechanism and make sure it's properly adjusted.

[kevin m. nelson]

Re: C2 alternator problems.....

hey joe&john,

well, joe was right! the alternator swap still has the same problem. it doesn't seem to backfire as much, though. it still does the quick cutting out then a jump in idle before returning to normal. i'll see what i can do about the chock setting. would i be better off to remove the choke to see if that does it ? kind of like an L88 with no choke, huh ? let me describe the prob a little better now that i've played around a bit....first of all it takes about 4-5 pumps of the carb to get it to fire in the morning. i've been told big blocks need alot of fuel in the morning.then after you turn it off is when the prob exists. if you start it up right away, it's fine. if you wait 2-5 minutes or longer it starts right up then immediately almosts dies on its' own then within a split second revs back up to idle and sometimes backfires, but not all the time with the backfire.it seems the longer it sits before restarting the worse it gets. i'll keep ya posted
thanks guys,

kevin

[John H.]

Re: C2 alternator problems.....

Kevin -

If the choke is properly adjusted (including the blade opening gap with the vacuum break/pull-off engaged), it should start almost immediately with one stab at the pedal to set the choke and give it a shot of fuel.

[kevin m. nelson]

Re: C2 alternator problems.....

john,

i'll give that a try in the morning when it's cold. after playing with it today i found that when you turn it off it starts right up fine untill approximately 15 seconds have passed. then it's hit the key, starts right up, goes to die, then revs to about 2 grand then settles right down to idle. all this happens in a split second or two. lately, no backfiring, though. i'll keep on plugging away!
thanks.
p.s. i found the alt. prob. the bracket inside that holds all the doides had a hair line crack. that problems solved. no more sparking!!!!!!!

[kevin m. nelson]

Re: C2 alternator problems.....

well guys,

the choke settings all check out fine. could there be a possible malfunction in the t.i. system ? by the way it acts, it seems to be electical...right after starting it drops off as if it looses power, then shoots right up to 2 grand and settles back to idle within a split second. are there any shops in the northern ca. area that specialize in t.i.'s ?
thanks,
kevin