Replacement Coil?

LSolheim

Member
Although I know the ignition system is basically standard, can anyone recommend a replacement coil they have used. Presently I have an original, stock "screw-on" coil in a positive ground system modified w/ a Pertronix distributor pickup.

I have been chasing an intermittent problem where periodically (usually on a hotter day, but not always) the engine will begin to miss, eventually dying. The miss will begin earlier if the headlights are on or become worse if they are turned on. I now figure that is due to additional current draw. Changing rotors (new English production), distributor cap, wires and plugs did not make a difference. I also changed the headlight switch, as the 40+ year old contacts were quite worn.

The coil was so very hot yesterday it could not be touched. I then discovered that a ziploc bag w/ ice placed on the coil solved the problem, at least for the next ride. Fortunately the passengers wern't nervous. So it is now coil replacement time.

Thanks,
--Larry
 

LAH20CAR

New Member
I had the same problem after I put in the Petronics but doubt that caused it

The coil got so hot you couldn't touch it for long

I put in one of those fancy ones from the same guy that sold the Petronics unit

When I replaced the old one, I put it in with the wires at the top rather than the bottom as stock on the Amphicars-----at one time I ran across an email on a Spitfire site, that all coils should be horizontal or vertical with the terminals on top as the coil is filled with liquid to keep it cool.

Now it still gets a little hot, but you can keep your hand on it

Of course, it depends on wether yours is - or + ground as to which way the wires go---if it is wrong your coil will get really hot before it goes bad completely.

good luck
 

Canadian four amphs

Amphicar Expert
I do Stock the replacement coil with the screw on cap..
they are around $35.00 and I do stock the screw on ends by themself,s along with all engine parts.
GORD SOUTER.
click on my web page at top of this section for my parts list and stock!
 

jfriese

Active Member
I use the Pertronix coils with the Pertronix ignition systems. I've also used various regular coils and they all run quite hot but I've never had a problem with them.

John Friese
67 White
67 Red
 

LSolheim

Member
Well, I've received and installed the 3 ohm black, oil-filled Pertronix coil with a nice 90 degree coil wire. A neat package.

Today is supposed to be around 90 (very HOT for here), so it should be a good test environment to see if the problem has been resolved. If not I suppose the distributor Ignitor module itself or even the voltage regulator could be suspect.

The inability to consistantly replicate the issue and, when it happens, the corresponding loss of power (ignition?) when the headlights are turned on is the stumper for me. Where could the current go?

But I am getting ahead of myself - we'll assume all will be resolved!

Keeping cool --Larry
 

Midwest Amphicar

Worlds Largest Amphicar Destination
Use your meter and look for loss on main battery cables. They can look good but corrode internally. Another area is dimmer switch could be going bad and is actually starting to short out. And the one area You really need to be aware of is the fat red wire. This wire is a factory defect. It is hot with no fuse. It rubs on metal dash then finally shorts and cars have caught on fire. Erics car almost burned in driveway, Joel in Florida caught fire while in the water. Neat thing about it car does not have to be running for this event to take place. I add a fuse at rear junction block. Later Dave the Wave
 

LSolheim

Member
Sounds good, Mr. Wave. I do have a battery switch which I leave open when
not in use. I will be adding the in-line fuse, as noted.



The part that bothers me about this problem is:

1. Intermittent and not necessarily reproducible

2. Seems to be related to ambient temperature - always OK out-of-the-box,
but occurs after some operation. Engine temp issues are all resolved and
operating temps are OK.



Thanks,

--Larry



From: Midwest Amphicar [mailto:]
Sent: Sunday, June 29, 2008 8:36 AM
To: lrsnpark@gmail.com
Subject: RE: [General Amphicar Discussion-t-20062] Re: Replacement Coil?



Use your meter and look for loss on main battery cables. They can look good
but corrode internally. Another area is dimmer switch could be going bad and
is actually starting to short out. And the one area You really need to be
aware of is the fat red wire. This wire is a factory defect. It is hot with
no fuse. It rubs on metal dash then finally shorts and cars have caught on
fire. Erics car almost burned in driveway, Joel in Florida caught fire while
in the water. Neat thing about it car does not have to be running for this
event to take place. I add a fuse at rear junction block. Later Dave the
Wave
 

LSolheim

Member
For those of you using a low pressure (?) electric fuel pump, where did you
locate it? Carb side of engine-driven pump? Tank side of engine-driven
pump? Or id did you bypass the engine-driven pump all together? Also is it
switched or providing full-time pressure?



--Larry
 
R

Ron Green

Guest
A coil is easy to check with an ohm meter (between the low voltage + & -). For a 4 cylinder engine it needs to read between 3 and 5 ohms and the Pertronix instructions back this up. Check your old coil both when it is cold and hot and see what readings you get.
 

CapnJohn

Amphi Guru & Former IAOC President
For those of you using a low pressure (?) electric fuel pump, where did you
locate it? Carb side of engine-driven pump? Tank side of engine-driven
pump? Or id did you bypass the engine-driven pump all together? Also is it
switched or providing full-time pressure?--Larry

Larry, You want the electric pump as close to the tank as possible. They are designed to push the fuel rather than pull it like the mechanicals. I have used the lower heater mounting bolt for a location. Then it is hidden. I also have a hidden switch for it as I use it for a backup primarilly.
 

LSolheim

Member
John, using the electric fuel pump as a switched backup . . . that means you have it in-line and normally just let the mechanical pump pull-through it? Then when needed (vapor lock/whatever) you turn it on and push fuel to the mechanical pump, easing it's load?

Thanks,
--Larry

Larry, You want the electric pump as close to the tank as possible. They are designed to push the fuel rather than pull it like the mechanicals. I have used the lower heater mounting bolt for a location. Then it is hidden. I also have a hidden switch for it as I use it for a backup primarilly.
 

CapnJohn

Amphi Guru & Former IAOC President
John, using the electric fuel pump as a switched backup . . . that means you have it in-line and normally just let the mechanical pump pull-through it? Then when needed (vapor lock/whatever) you turn it on and push fuel to the mechanical pump, easing it's load?

Thanks,
--Larry

Yup, that's it exactly! If the mechanical pump fails, I have a backup to get me going too. No more cranking the starter forever after she sits over the winter either.
 

ramblerdan

New Member
We have had the same problem with the ignition coil overheating and failing, first with points and then with Pertronix electronic igntion, though not yet a Pertronix coil. Could someone who has oriented the coil right-side-up (or horizontally) please explain how this was accomplished? Auxiliary mounting plate perhaps?
 

DavidC

Amphicar Expert
Doesn't matter which way round the coil is fitted.

Modern coils (oil filled) run hot no probs.

Lucas Gold is one of the best.

Coil most likely to fail if you change polarity - it does make a difference.
If you are still +ve ground you need to wire a new one backwards.



David C





From: ramblerdan [mailto:]
Sent: 08 July 2010 21:14
To: david@manbus.com
Subject: RE: [General Amphicar Discussion-t-20062] Re: Replacement Coil?



We have had the same problem with the ignition coil overheating and failing,
first with points and then with Pertronix electronic igntion, though not yet
a Pertronix coil. Could someone who has oriented the coil right-side-up (or
horizontally) please explain how this was accomplished? Auxiliary mounting
plate perhaps?
 

ramblerdan

New Member
Thanks for the reply.

OK, good to know that the coil is OK upside-down and too hot to touch.

Polarity should be correct for it to run for some miles before konking out, eh?

Have also suspected a bad connection, caused or exacerbated by bilge. Problem has only happened in the water. Gonna have to examine/clean more connectors, I guess.
 

DavidC

Amphicar Expert
No, in fact it'll run at reduced efficiency if connected backward but can
then fail suddenly - however this is more likely with the original coils
than new ones. A Sun or Crypton diagnostics machine show you the reduction
in spark KVs when coil is wired backward, a new coil on Neg Ground car has
connection to distributor on CB terminal.



Replace leads, cap and rotor first.



David C



From: ramblerdan [mailto:]
Sent: 09 July 2010 01:50
To: david@manbus.com
Subject: SPAM-LOW: RE: [General Amphicar Discussion-t-20062] Re: Replacement
Coil?



OK, good to know that the coil is OK upside-down and too hot to touch.

Polarity should be correct for it to run for some miles before konking out,
eh?

Have also suspected a bad connection, caused or exacerbated by bilge.
Problem has only happened in the water. Gonna have to examine/clean more
connectors, I guess.
 

Woodsie

Member
The Stock Coil will get real hot and fail - Its a must to get the matching
Pertronix coil and pick up*- the* coil they sell is called a Thruster i think -
Well enyway its made to get really Hot -
Pertronix is a very cool product - once and done

Whats that-*I think i hear*a** *Keep it Stock** *Echo*
************************************************************************************************************
*Have Fun************** ************************* *Dave
Ps- they sell*a chrome matching bracket for the Coil



________________________________
From: ramblerdan <>
To: dwoods164@yahoo.com
Sent: Thu, July 8, 2010 4:13:32 PM
Subject: RE: [General Amphicar Discussion-t-20062] Re: Replacement Coil?


We have had the same problem with the ignition coil overheating and failing,
first with points and then with Pertronix electronic igntion, though not yet a
Pertronix coil. Could someone who has oriented the coil right-side-up (or
horizontally) please explain how this was accomplished? Auxiliary mounting plate
perhaps?
 

DavidC

Amphicar Expert
The original coil (normally date stamped 1962 or 1964) really shouldn't be
used. They had bitumen to separate the windings. Later oil filled are much
better, be careful about really high power coils as they stress the HT
system and can cause tracking misfires. A Sun or Crypton tuner will tell
you the optimum figure for KVs.



David C
 
R

Ron Green

Guest
For what it’s worth, I have been running Pertronix’s for 7 years with a stock amphi coil with zero issues (over 6,000 miles to date).Whatever coil you use with the Pertronix’s must read at least 3 ohms resistance as stated in their instructions. Many 12 volt car coils that NAPA, etc sells will only be in the 1.5 to 2 ohm range.
 

ramblerdan

New Member
Still tearing my hair out over this ignition problem. Using an incandescent-bulb tester, I see a spark that is intermittent and weak. Have replaced the coil twice and the Pertronix module once. Cap, wires, and rotor are new. Cap has no cracks or evidence of arcing that I can see, and no cruddy buildup anywhere. Coil is now wired backward, as recommended.

With ignition off, battery shows 12.2V.

With ignition on but engine not turning, the battery shows 11.7V—subpar I know, but enough to matter? It still cranks the engine nicely.

Ignition relay to ground with coil disconnected: 11.7V (same as battery), so I think that rules out resistance in the relay.

Ignition relay side of coil to ground: 10V

(+) to (-) posts on coil: 8.8V

Coil measures 3.2 Ohms.

I can't find these sort of specs in the Amphi shop manual. Do those numbers sound reasonable? I'll pull the plugs again today (they're probably wet from cranking without running), but even if the plug were fouled, wouldn't the tester show a spark?
 
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