Wow! Stopped dead on the road by a bad coil

[Sunroof]

Interesting evening. My wife and I took our 73.5T out on a cold Atlanta night tonight for a run around town and all systems are okay until suddenly the car dies flat!! I mean just dies!!! No sputtering, no re-ignition, nothing. I managed to coast over in the turning lane on a major thoroughfare and go into my "I am a tough Pelican Head survivial mode"!!

I listen to the CD hum, a-okay, fuel pump working, okay. No major tools onboard but a glovebox full of relays. Okay I change out everytihng. Nada, nothing. Cranks beautifully but no ignition. Check the rotor and the points and they seem okay. What can it be?

Well stood in the freezing night air waiitng for the flatbed to pick us up an hour later and we manage to get the car home.

Back in my garage I check for spark to the plugs and nothing, but something weak and intermittent from the coil. Luckily I had my old one around I saved. The one on the car was about two years old and a Bosch OEM unit. I change out the old one turn the key and she starts right up.

Now...the big question is.....can a coil just go out without warning? Can their be something more symptomatic going on deeper in the electrical system. I always thought a coil will burp, pop and belch before its give up the ghost. This was an instant drop dead action!

Always learning and always seeking knowledge. Would someone please lead me on the path of coil wisdom and itrs behavioral traits.

Thanks

Bob
73.5T

[JCR]

Yes they can just go... and they go quick, with NO warning at all.
Especially if they are the silver Brazilian built Bosch units - they are more prone to failure but I'm not sure on the specific reasons why.

[Oracle]

Yes,
Exactly that happened to me twice. Both were the Brazilian brand new bosch units (and they're not cheap!)
I bought a used black one (German made I think) and zero problems...

[BoogieOnSkis]

Happened to me too. But, my coil gave me a warning -- it was leaking oil. I thought the oil was coming from somewhere else rather than the coil, until my car died just like yours.

[Wayne 962]

And, those coils are now back in stock, thankfully, after disappearing for a long, long time. 30 available right now, probably not for long. I picked up a couple of spares for myself...

-Wayne

[wachuko]

Yes it can... happened to me last Friday... after troubleshooting the heck out of the system....removing and replacing the distributor cap and rotor, I took the CDI off and sent it to be rebuilt... Got a call this Friday that the unit is working fine and nothing was needed... and that I should check my coil...

Well, I had not looked at the coil since it looked new (PO had replaced it not too long ago).

I see that the Blue Bosch Coil is back (was not available Friday when I checked Pelican) so I just place an order for one so that it gets here by the time the CDI arrives.

http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_ELignt_pg8.htm#item34

This is the 1983 911 SC that had the problems.

[ToddM]

Not to play devils advocate, but have any of you tried the MSD coils?

I am repeatedly disenchanted with anything wearing the Bosch label these days

[Sunroof]

The original coil I replaced that "silver" unit with was black. Now I see "Blue coils" on several vendor sites at a premium cost. So whats the "black coil"? Original factory Bosch? Prices are running tha gamut betwen vendore.

Wayne, your coil is advertiesed as the silver unit exactly like the
one I had (failed last night) with the same decal features. Are these no longer made in Brazil?

Thanks
Bob
73.5T

[Won]

Originally posted by ToddM
Not to play devils advocate, but have any of you tried the MSD coils?

I am repeatedly disenchanted with anything wearing the Bosch label these days

Apparently, yes, with the right part number...

Link: MSD blaster coil vs. Bosch coil

[lonewolf]

isn't the solid blue coil for cars without CD ignition and the silver or black for cars with CD?

[BoogieOnSkis]

Not to play devils advocate, but have any of you tried the MSD coils?

Judging from others experience on this forum, the MSD coils don't last as long as Bosch. So the cheaper MSD coil may not end up being "cheaper".

The only real gains of MSD are seen during heavy acceleration. But I don't track my car, so why should I go with MSD? (rhetorical)

But what really kills MSD for me is that I need another manual (besides the Porsche manual) to service it.

[Patton]

Adds a new sing to the term "silver bullets" Darn, I'm running with two currently will look to replace if those 30 aren't gone.

[wachuko]

Originally posted by ToddM
Not to play devils advocate, but have any of you tried the MSD coils?

I am repeatedly disenchanted with anything wearing the Bosch label these days

I did... I went out that same Saturday to a race shop here in Orlando and purchased all I needed (this was after calling Pelican to find out they do not have the ability to ship on weekends)... but decided to wait and see what was the real culprit before I made the change...



So by Wednesday I should have the car back to normal operation with all stock settings and a MSD system ready to go in whenever I feel like messing around with this to do the swap. Good thing the MSD does not have an expiration date anywhere...

[rattlsnak]

Bob, you just need to buy my 993 and be done with it..

[limble]

The coil arced so badly on my 79 that it melted the coil wire and the plastic on the coil. I coasted to the side of the road, fortunately, less than 50 feet from a Pep boys parking lot. Bought a new coil wire, the coil was still good, and I was gone. Rarely have that kind of luck.

[ToddM]

wachuko,

Good move. You are going to love that 6AL unit... though you probably won't love the installation or the cost of installation and the trick of finding a good mounting location.

I have still yet to see two identical 6AL installations.

This is a good time to make sure your ground strap and mounting point are up to par. If not you could waste a lot of time trying to troubleshoot your new install.

Good luck.

[gulf908]

....And, those coils are now back in stock....

Wayne,

Can you clarify pls.
Are you saying that the black German coils are now available again ?
If so can I have 2 for my '71 S ?

TIA,
Dennis.

[JohnJL]

Sorry to hear that. Graham (forget his last name) suffered that same failure on the last leg of the Targa Tasmania last year and lost his huge lead and I believe he DNF. In an 74 or 75 I believe...

[gulf908]

John,
That was Grant Geelan from ******** Hamilton who was co driver to Bill Pye in Bill's '76 Carrera 3.
They were leading their class in last year's Targa Tasmania when on the last stage - guess what broke? Their NEW Bosch silver coil !
After their return to Sydney,the rumour was they were looking to Bosch to sponsor them next year !!

Cheers,
Dennis.

[JohnJL]

You're right Dennis, thanks. Although I'm not sure I'd be looking for Bosch to sponsor me after that...or maybe just change out the coil for an MSD after the scrutineer turned his back!