help-just broke down and car won't start!

Stevehose

Stevehose

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I was merrily cruising along when a very large bang came out of my exhaust. Car won't start. Am getting fuel, not sure yet on spark as my tools are en route. I am suspecting either the coil or pertronix has failed? How do I test the coil? Fortunately I have a spare points and condensor if it turns out to be Pertronix. Any other electrical other than plugs I should check? Thanks.
 
started!

Swapped out the coil, no dice, put old one back in, and before tearing into pertronix tried once more and it started, must been a loose ignition wire. But I have a large hole in my exhaust and hope it makes it home.
 
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Moral of the story

Check your coil to rotor wire and spread the metal contact so the ends fit tight all the way in! Apparantly mine went intermittent and with the triple webers allowing plenty of fuel to enter the cylinders and then out the exhaust created quite an explosion, so much that it blew open the rear Bosal at the seam about 12" long and 3" wide! Muffler shop banged it back together and welded it shut until the new one arrives. More adventure today than I bargained for.

IMG-20130518-00434.jpg
 
Check the wires connecting to the coil.
The wires may be worn or corroded and basically, not connrcting.
It was in Tech Talk talk a month or so ago
 
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To cause a backfire big enough blow out a muffler I'm not thinking faulty coil but a timing issue. Fuel ignited out of sequence so you had power and even if the Petronix was faulty the rotor would have to have been in position to fire the cylinder. I have had a similar event when an untighten distributor rotated. Might check that.
 
Stalled again!

Ok looks like I have a problem. Was driving the car again and it died but at least it ddn't go boom this time. Pulled over to a shady spot and was able to get it to start again after a few minutes of wiggling wires (not certain that did anything).

So now I get to search the archives for the other members' similar problems, any advice appreciated.

Will check:

Fuel filter (although only 6 mos old) however I am getting fuel at the carbs.
Load shedding relay - will remove and inspect
Coil (although swapping coils this am the first time had no affect). What should a Bosch Red coil measure Ohm-wise between the connections and between the connection and the output wire?

Ballast resistor appears ok but might replace.

The ignition switch was replaced in the past

How does one check Pertronix, wouldn't the thing just grenade and not be intermittent since it is basically an IC chip? It's secured in the distributor well.

I have cleaned all contacts where wires attach at the coil.

What else? Frustrating!!
 
Steve,

If you have the red coil you need a 1.8 ohm resistor, the original is only 1.1. I had this same problem on the 69 2002 I recently sold. Engine would shut down with no warning on freeway, pull over, wait one or two minutes and it would fire right up. It might happen again or not for 30 miles.

Chris
 
Yes I have seen your suggestion on this before, I have had the 1.1 resistor and red coil for a couple years now with no issues, could it have slowly fried my coil?


HB Chris said:
Steve,

If you have the red coil you need a 1.8 ohm resistor, the original is only 1.1. I had this same problem on the 69 2002 I recently sold. Engine would shut down with no warning on freeway, pull over, wait one or two minutes and it would fire right up. It might happen again or not for 30 miles.

Chris
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Ballast Resistor

It just overheats the coil. I replaced the resistor and never had this issue again. Bosch part number 0 227 901 014, search this number on AutohausAZ and it pops up for $27.36. Search for ballast resistor and nothing shows up!

Chris
 
wow, that is an issue ! a blast in the end rear muffler ?

i can not figure out what might be the cause, but, now i am realising that your setup is the same as mine, except for the webers, that means that you may use the same type of coil that i use, this is the blue one, it is the more powerful version that was used originally (it goes without resistor)

i do not have a spare of a blue coil and they are NLA, (the original made in germany, i mean)

if you want to check things i can send you a brand new bremi coil (original spare from bmw dealer), and a little used beru coil, that worked ok in my car, yes i know they will not be there tomorrow, that is the bigger problem, but if it helps...
 
The Blue coil is definitely not more powerful, it has an internal resistor. Don't ever use it with an external ballast resistor.
 
The muffler shop guy said the explosions was likely in the manifold, blew back out the downpipe and when it hit the resistance of the back muffler, had it's way with it.


deQuincey said:
wow, that is an issue ! a blast in the end rear muffler ?

i can not figure out what might be the cause, but, now i am realising that your setup is the same as mine, except for the webers, that means that you may use the same type of coil that i use, this is the blue one, it is the more powerful version that was used originally (it goes without resistor)

i do not have a spare of a blue coil and they are NLA, (the original made in germany, i mean)

if you want to check things i can send you a brand new bremi coil (original spare from bmw dealer), and a little used beru coil, that worked ok in my car, yes i know they will not be there tomorrow, that is the bigger problem, but if it helps...
Click to expand...
 
Steve, did you figure out the issue? I'll have to document this one and save so I'm not asking the same questions when it happens to mine :-)
 
No not yet, I am the process of working through it.

I am taking Chris' advice regarding the ballast resistor since I have not been running the correct one for the red coil, however when I stalled out the other day I replaced the coil with my original black one and it didn't start...hmmm

So given the randomness of this problem I am working back towards the plugs so am replacing my Pertronix and ignition wires.

I will be in Germany in 3 weeks and have sourced a German made red coil to pick up there since he won't ship it to me here and I don't want the Brazillian one just because...well, because!

Rotor and cap are new. Fuel supply is ok.

If that doesn't fix it my wife will say no mas!

I'll keep you posted.


Peter Coomaraswamy said:
Steve, did you figure out the issue? I'll have to document this one and save so I'm not asking the same questions when it happens to mine :-)
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All I can offer is sympathy and prayers but coming from a luke-warm athiest I don't know how powerful they are. My skills are way too limited to offer advice.
Steve
 
Stevehose said:
The muffler shop guy said the explosions was likely in the manifold, blew back out the downpipe and when it hit the resistance of the back muffler, had it's way with it.
Click to expand...

Still think it is a timing issue. Got fuel / got ignition...just happened to get together at the wrong time. Combustion on compression stroke before the valves closed and hence the massive backfire.

John
 
I see your point but how do you explain it running perfectly for 2 years, stalling/blowing up, restarting an hour later, running perfectly, then stalling again, and restarting? My timing is 30 degrees all in set on the dyno, so not out of range.

Lotuss7 said:
Still think it is a timing issue. Got fuel / got ignition...just happened to get together at the wrong time. Combustion on compression stroke before the valves closed and hence the massive backfire.

John
Click to expand...
 
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