Compu-Fire Failed?

[Cadaver]

the compufire is POTTED , yes it is.
Potted in electronics means it's epoxy filled.
for proprietary protection, water, gas , oil and heat dissipation.
nobody advocates that. (unless burned up and doing for fun, yes, i do that)


SOP (std, op . proc) METERS.
in school the instructor said, 1000 times.
class, always check your test instrument first before working.

Ohms, check that shorted leads work and show zero on all ranges.
good !
on the high Res range you can measure your skin resistance. if not meter is dead. ( or you are a cadaver. lol)
then put it to 20v volt range , connect to a 9v transistor battery (old name)
it shows 9v, good.

last (most DMM's have fuse , Fluke meters for sure.)
and that fuse will blow every time you connect the leads in amps mode
across any power source. ( you attempted or measure infinity ,no?)


in the old days the meter blew to kingdom come.
every meter i touched for 20 years, 60-80s, the meter was blown, or the range blown. (shop group meters) that is why I always run my own meters.

so, to test the amp range, the instructor said
now remove 1 test resistor from your tool box
(keep lots, kids... )
now test the amps (current) through said resistor.

lets say meter is on 20 amp range. ( using a car battery)
so i pickup a 12-15 ohm resistor 15watts , and put it in series with the Amp meter and the battery
rule 1(never put meter in parallel (across) any battery or power source)
the meter will read near 1 amp.
go to 2 amp range, 1 amp. (math: I = E/R 12/12 = 1amp)
i have a heavy duty 5 ohm 50 watt resistor but that takes special order.

the .2 amp range is use. 120 ohms for 0.1 amps reading.
for .02 amp range i use 1200 ohms for .010 amps reading (mid scale)

with a DMM , all ranges can go dead with a fuse blown, some just the amps ranges.
with analog meters. you can blow out any or all ranges.

we do this all with out thinking of it, it is burned into our minds,
never trust the meter, validate it or, waste the whole day chasing phantoms.

don't feel bad, everyone blows the fuse, at least one.

rule 2
always start on high amps and work low. that way you dont overload
a range.
rule 3: chuck the bugger and get an amp clamp meter. non invasive testing...
is so cool.

do not measure starter current on the 20 amps range. (same with alternators)
you are using the wrong meter....
_________________
for sale now.
in Samba classifieds....1968 T1.

[gtkid2002]

Alright, it's monday and I'm outside while it's still nice.
Battery voltage at current time: 12.43 @ terminals
Battery voltage at coil (+): 12.18v ((-) being ground strap)
Battery voltage at coil (+): 12.19 ((-) being engine block)
Resistance from compufire unit to ground strap: .3 Ohms


Cranking voltage from Coil (+) (during cranking) - about 10v
Cranking voltage from coil (-) (during cranking) - 10.6v

resistance from ground strap to distributor - 5Ohms
resistance from ground strap to alternator - 13 Ohms
resistance from ground strap to engine block - 8 ohms

Coil is a Bosch blue with german on it, and what appears to be a 1040 stamped on the bottom. not sure about the 10 though, but I can make out the 40.

Multimeter has good leads. I know I did some damage because I forgot to switch it from it's 10A setting to Volts when I measured battery voltage a few weeks back... It did some fizziling, but still works oddly enough. 0's on all settings.

Just did the parasitic load test. For the first five-ish seconds or so, it reads .22A, then after those first five seconds, it goes down to .01A

As for the stereo being wired wrong, that's probably so, but it'll work most of the time, which is what confuses me.

And yes, I know it's not stock. When I got the car, it didn't even have the cutout in the dash for a stereo. Still doesn't have a radio antenna either (thank goodness, I hate radio).

And yes, I know EOC (engine off coast) is dangerous and illegal, but considering I only really do it when going down a hill, and my brakes don't change whether the car is on or off, I don't really care. I also don't have the joys of having a storage scope or a live data logger. I probably could try something with an arduino that I have lying around, but I would have to buy the shields for that, then get into coding, and the next thing I know I'm broke and it's two months later and I still don't have a running car.


I'm just gonna pop in the friggin points and see if I can get it running. I need a car more than I need the compufire unit, and worst case I'll just take it up with the compu-fire company and see what they say.

[Cadaver]

the compufire , is dead
or the trigger wheel is to far.

Cranking voltage from coil (-) (during cranking) - 10.6v
this singnal should pulse. and is not.
so it's not firing. (bad main output transistor, or bad trigger.)
sorry it's bad. a real pisser. and kick to wallet.

the points will work, just make sure the condensor is back in.
nice set of readings ,very complete.
_________________
for sale now.
in Samba classifieds....1968 T1.

[gtkid2002]

Forgot to mention - also did a few more tests.

Wire from battery positive to coil positive - Nothing
Hooked the timing light up from the battery terminals, and tried it again. No activity.

Hooked timing light up to battery terminals, undid added coil wire (tried it as I would normally start it: Nothing. Nada, zip, zero, zilch.

I'm just gonna pop back in the points and call it a day. Great waste of $90 that I just did trying to get back to the way I had things.

[gtkid2002]

HOUSTON - WE HAVE A MAYDAY.

Points are back in. Guess what!






No spark. Nothing from the timing light, not even a single sputter. Just cranks like the day is long.




Dammit.



Going to pull the battery, give it a charge, and get a ride to Portland, OR tomorrow. Hit up Avery's Air cooled in Woodland, WA on the way back, see what he says. AGH. Getting SLIGHTLY agitated with this.


Edit -

Well, I thought about things, and I pulled the coil.

Resistance from (+) to (-) terminals on coil: 0 Ohms at first, then climbs to 3.6-3.8Ohms. Fluctuates from there a little inbetween the two figures.

Resistance from (+) to spark plug tap: 5.05kOhms
Resistance from (-) to spark plug tap: 5.05kOhms

Now I think I have a black Bosch (german, I know it is) coil I pulled from my old Baja. Might have been from my old Fiat, but I don't remember. That's what I was running when I started running points, so maybe this coil is just... sucky?

The coil says:
Bosch 12V
Ohne Vorwiderstand
Encendido Convencional
Sin Reisitenca
Without Resistance

Fabricado para:
Robert Bosch, S.A. DE C.V.

Bottom has a stamp of 040. I thought there was a one there, but it was a mis-stamped 0.

I think I have the crappy avoidable bosch blue coil. Oops.

[Cadaver]

the coil is burned up?
even a coil operated with no condenser, makes 1/2 the normal spark.
an ohm meter is not the last call , on a any coil or transformer.
(lots of tests there are, in a factory (IN/OUT Z, turns ratio, HiPot, etc.)
leaving the coil keyed on for too long does that, damages the primary.
it gets SUPERHOT and melts.

You Can take any coil and bench test it. (i can do this is 5min flat on a fender next to battery)

1: on the bench. (box of jumper wires (called alligator to alligator clips)
2: 12v battery on the right. or a 12vdc power pack (5amps at least)
3: connect up a spark wire to the HV tower. and a spark plug on the end
4 connect the spark shell to COIL minus. (i wrap wire in the threads to make my connection to ground ,battery minus)
5: connect coil minus to battery minus terms .
6: touch for 1second then release the battery plus wire to battery.

sparks at each release. .025" on spark plugs.
the test works better if you wire in the condenser.
but that is one more part that can fail.

in the car i check for coil current. (ammeter)
i measure my current with points closed then open.
if zero all the time.?
the coil is bad, the wires are bad,(open) or the points are filthy.
even new points (gapped) can fail if you dont draw clean paper through them.


on car tests: (no spark at coil)
I cap off rotor off
I spin crank until the points are closed. (im off the cam tips)
I flex my points. I look and see they spark, this is the 3 -4amps of current flow necessary for the primary of the coil to make spark.

if the point contacts dont spark at all, there is no current flowing. (fail)
if no spark there, there will be no spark on the HV side. Telsa rules here.

I then measure the voltage. at the points wire (green) 0v all the time,.
my coil is open
or
my wires are open (or the points are shorted (3 ways this can happen)
or
I get 12vdc at the points all the time.
my points are not closing even though they look closed. (yes, points can suck)
I burnish the points, an gap them , i draw clean paper strips through them.
I then look again, for contact spark,
still no spark, i find the breaker plate is not grounded. (current never flowed)

If the current meter is OTL (out to lunch)? you can use Volts.

i only need a volt meter to diagnosis this.
green wire. (points)
the points must go, 12v, 0v,12v , 0v as you turn the crank or there will
never be any HV spark at the coil.
key on.
if you un plug the points wire and the voltage is zero,there, the coil is open
or the green wire is open to coil or the coil has no power on the + term
if the coil does not have 12v at the Plus term the coil key Ignition path is open.

here are the other disty fails (only for lost spark there are many more)
1: condensor open (low spark)
2: condensor shorted, zero spark , and max coil current for ever.
3: vac adv. can , screw on right , is too long and hits points spring, shorting it to ground (cute , huh?)
4: missing ground strap in any 205T or M vacuum only disty.
5: the green wire out to bottom is cut/frayed and hitting the motor parts.
6: points dont really open. stuck at 0v .
7: points never close. stuck at 12v.
8: points pitted and misaligned and they are now shorted.
9; new points, the wire from said points at the crimp is bad, no connection.
cheap crappy points. can be bad , new. use Bosch.

those are all my DIY fast tests. there are more,
if you find the coil fails the bench test.
or more if it passes. we can work the problem on the car or on the bench.
either way.

i also have a buzz box that has an oscillating relay. that emulates points
this makes huge High voltage from the coil.

the condensor can be tested with a ohm meter analog. (no digital)
you set it to 1k ohms (2k ) then connect to the condensor
the battery in the meter charges the condensor UP.
you then reverse the meter connections and see that analog meter needle
jump hard and fast, that is a good condensor.
the charge in the cap, bucks the meter hard. (what's happening)
my meter has uFarads scale and can check that too.

ok that is all there is to basic spark.
i try to take measurements and not throw parts, that way i find the real culprit. (tow trucks suck $$)
_________________
for sale now.
in Samba classifieds....1968 T1.

[JerryMCarter1]

well you never tired my simple test so
If you would have run a 12 volt wire to the coil - the car would have run fine- at least I am pretty sure- I think you have a bad ign switch or wire, which is the most common part in the ign system to fail-
When they fail -- the starter key over to start sometimes will not add power to the coil
Never saw such a bunch of tests ( pages and pages of bunk ),,, and run around in my life
e- mail me and I will give you my phone number – we will isolate the problem in a matter of minutes

Jerry
_________________
Experience always triumphs over hearsay and You get to select which theory to believe

[Cadaver]

long post, ask questions, it about all the above, coil , condensor and electronic ignition (im a tech, i fix this stuff ( the insides). (I fix the high end stuff)
Jerry wont like my long post. so JERRY DONT READ IT. it's NOT FOR YOU.
its for the OP and to debunk the other posts on this forum on topic.

[Cadaver]

[JerryMCarter1]

Then we come to the term intermittent
_________________
Experience always triumphs over hearsay and You get to select which theory to believe

[Cadaver]

only you proposed intermittent, and is always possible for sure, any car made, but he never said that nor implied and in fact said the opposite here.


we dont have post number here.so

7:31pm yesterday

[gtkid2002]

[JerryMCarter1]

well your on it now - if you have volts to the coil --
Then replace the coil

If you still have problems fix the dist.---GWD It doesn't take a freekin master list of fifty test to get to the problem

Honk it dude
Jerry
_________________
Experience always triumphs over hearsay and You get to select which theory to believe

[Cadaver]

i sure dont. for you an I but... its not...
it only takes 5min.
but some folks shy away from electrics.
ever notice that ?

power to coil
i test coil manually, it fails, new coil
i test coil manually, it passes but points are failing, i fix points
i put in compufire, it fails. but points work.
I find compufire ground bad
I find computire power wired wrong.
I find compufire coil minus broken wire.
or my trigger is dead, (this can only be proven if all the above is good)

8 checks, jerry not 50.

jerry, you like the drama of spoon feeding out the tests. 1 by 1 and 50 posts
yes?
To me a car is box of resistors (electrics).
_________________
for sale now.
in Samba classifieds....1968 T1.

[Cadaver]

that is correct OP
transformers are fussy
and for sure with High Voltage
they can flash-over,
and the insulation resistance in side can break down
on the vw , the primary burns up, because someone keyed ON and left it on too long (5min max is a good rule.)
btw ,newer systems (or upgraded, blush) can have progressive destruction
effects to the parts (aka, the walking wounded) by shorting out the coil output (a dead zero ohm short, NO GAP)
or by running with the spark plugs not connected (load) (can show proof at ASE or SAE.org)

see the bottom right corner photo (black back grounded)
for a beautiful example of how high voltage can break down an insulator.
http://en.wikipedia.org/wiki/Electrical_breakdown

keep a spare coil, (in my case , running 40kv unloaded, ) this can happen
even more easy.


btw I have a Model "T" ford, Ignition Tremble coil with a Jacobs ladder attached (an early Distributor less system)
on my bench and a power pack to drive it.
a WOOD coil , with tar filling and built in vibrator points.
we can make up the same test device for your coil. (i have one too)
it really can put out lots of voltage and is very fun to watch in action.
very Frankenstein. spark and yes ,FLAMES.
for stock car coils , i test them only under load, never open circuit.


http://www.mtfca.com/discus/messages/118802/147334.jpg
_________________
for sale now.
in Samba classifieds....1968 T1.

[gtkid2002]

Alright, just took a few measurements on the black coil I'm going to pop in and try.

From Pins 1 to 15: 1.6-1.8 Ohms (contacts are DIRTY)
From Pin 1 to Center Tap: 8.01kOhms


And right on top?
BOSCH
MADE IN GERMANY

On bottom?
0221122012
932 then something in a little roundish box
KW 12V


http://www.ebay.com/itm/Alfa-Romeo-BOSCH-COIL-0221122012-milano-gtv-6-gtv6-bmw-/120660811176

So this is the one I pulled from my fiat then. I know that because it has the exact -same- mounting bracket on it.

But hey, a coil from another car is still a coil, so long as it -works-.
Saves me the $$ from buying a new one for now. Just had to part with my 70'sish SG knockoff for some cash too. Ah well.

[gtkid2002]

Hurray! It was the coil the entire time! Popped one in and it fired right up. Tried to adjust the timing, but when I set it to what I -thought- was right, it wouldn't idle. So I just moved it to where it idles now. The little lumps that show timing on the inside of the pulley are now where the belt comes right off the pulley on the drivers side. I just set it to where it would idle, no clue if it's right or not, but for now it runs, and that's all I need. I'll do some more looking up into idle and whatnot and try and figure this out.

Thanks everyone for the help!

[JerryMCarter1]

intermittent
Just like I thought
_________________
Experience always triumphs over hearsay and You get to select which theory to believe

[Cadaver]

there are 2 parts. one was bad, clairvoyance is grand, reality another.
and the new (Fiat) coil,, has a too low input resistance.
so you are at square 1 again. IMO.

contact your electronic ignition maker and be sure they are happy with
your coil type. THEY DO KNOW !

this is by no means a full list of mistakes you can make with coils.
pit falls.
excessive primary conductance (too low resistance (DCR) or impedance)
if electronic , same and not using Epoxy, or not using a coil with the correct core type for electronic usage)
running higher voltage in the secondary than the coil was designed to do, CDI. (use CDI rated coil , if using CDI)

running a coil that has too high a Back EMF for your aftermarket ignition.
this shorts out the transistor due to Destructive breakdown of same.
running the wrong coil can burn the points up real fast.
running the wrong coil can cause it to overheat. (no ballast)
end short list.

any Bosch site has this...
http://www.repcotrade.com.au/go/news/hints-and-tips-when-replacing-transformer-ignition-coils
_________________
for sale now.
in Samba classifieds....1968 T1.

[ashman40]

Did you set the point gap/dwell before you timed it?
If the timing marks are rotated counter clockwise from the top of the pulley where the case split is, that means you are more advanced. If the TDC mark is where the fan belt and pulley touch you are close to 30btdc. Is this at idle or at full advance (3500rpm)?
30btdc at full advance is fine... at idle that is crazy!
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}