it died last night...posible coil issue?

[teenerted1]

engine starts to slow down as i come to an intersection but doenst quite die

as i go thru intersection HUGE backfire and the thing dies.

was able to get it to a parking lot coastng. scared the whole 7-11 parking lot accross the street
(not another skyway shooting )
guy on a harley stopped to help out (was the only one not ducking for cover) he was nice enough to give me a ride b!tch home to get my other car and help me tow it home. his karma should be good for a month on that move.



msd box, msd blaster2 coil, msd tach adaptor, SC distributor, and webers. volts are still ok from the optima battery, didnt drain trying to restart, and the the jump we tried didnt help. didnt want to push start since that would have put me even farther form home. not to hot a day so thats not an issue and it has been almost trouble free for the last three years, always starts.

i am getting gas and the starter motor turns but there doesnt seem to be any spark, thinking it could be the coil havent had a chance to check seriously. the dist. cap and rotor look ok, no cracks or anyting unusual. the green wire on the dist is in good shape.

any ideas what to check on coil or msd box before i start throwing money at this.

[ClickClickBoom]

Check the primary wire from the coil to the points, on an older car the insulation breaks down and shorts the primary signal out, ask me how I know.
eric

[kodioneill]

Year? Model?

[teenerted1]

eric
thanks
that was one of the few things i was able to check. pulled on and off and in good condition.
the plug wires are only a few years old and in good condition. we added new wires when the 3.0L was installed.

will do a better spark check tonight

[teenerted1]

Originally Posted by kodioneill

Year? Model?

1970 911t car
1978 3.0l sc motor using sc distributor,weber carbs, msd ignition, msd coil
1972 915 trans
there really is nothing stock left in the engine compartment.
it seems to be a spark issue but didnt have a chance to get into it much last night after club meeting. the fuel and starter motor and battery seem fine.

this car doesnt sit around not getting used...not a daily driver, but gets regular weekly back road drives. have put 6000 miles on it this year already, 2long road trips and a weekend drive almost every weekend. havent had one issue all year till last night.

i really am looking for ways to check the coil and msd ignition. i dont have the manual for both. i suck at electrical trouble shooting...but once i understand i take care off all my problems with success.

[Walter_Middie]

Ted,

I bet it's the coil. The Blaster 2 is an oil filled coil, and if you have it mounted upside down in the stock location, there is a part of the coil that the oil cannot cool. That's why they (MSD) recommend using the epoxy filled vibration coil.

Best way to test is to plug in a known good one - want to try mine?

[JJ 911SC]

Originally Posted by teenerted1

... guy on a harley stopped to help out

... not that it's going to help you with your problem, but I go to a lot of Cruise Night and Week-end shows (not the concour type because I would own point by the time they finish...) and H.D. rider are alway interest by the Porsche. Also the P.O. did not sell the car to a H.D. guy because his reason to get the car was that his new girlfriend did not like riding the bike. Luckily for me that was not a good reason

Now back to your spark problem, easiest way to check is to unplug a spark plug wire and plug a "good" use one, ground it, have someone crank the car and check for spark (easier at night).

[teenerted1]

Originally Posted by Walter_Middie

Ted,

I bet it's the coil. The Blaster 2 is an oil filled coil, and if you have it mounted upside down in the stock location, there is a part of the coil that the oil cannot cool. That's why they (MSD) recommend using the epoxy filled vibration coil.

Best way to test is to plug in a known good one - want to try mine?

bernie and scooter did mount the MSD coil correctly
i just found the MSD troubleshooting page on their site....the white wire check they have sounds pretty easy without needing a 2nd pair of hands.

i was going to do the spark plug trick too just didnt have the time last night.
have a few things going on tonight so may not get a real chance for a few days to evaluate.

i probably have bosch coil around somewhere to make sure it is the coil that went bad...will get another msd if its the problem.

[Walter_Middie]

just found the MSD troubleshooting page on their site....the white wire check they have sounds pretty easy without needing a 2nd pair of hands.

Trouble with this test is you still won't know if it's the coil or the MSD.

Let me know if you want to swap out the coil, MSD, or both from my car this weekend.

I know you'll get it fixed - it's just a matter of how much suffering you endure in the mean time. At least that's how it usually works for me.

[teenerted1]

they do have a second check with some red wire...but till i get a look at it tonite i'm not sure where i stand...i'll let you know if i need anything this weekend.

one of the MSD dealers is half a block from where the car died. but they usually are closed about the time it konked out so it wouldnt have helped me at the time.

[gtc]

I wouldn't be surprised if it was the MSD box... on the CanAm, Don (haycait) was talking about having a few of them crap out recently.

[john walker's workshop]

why not find a good bosch unit and forget the msd? it's just a cheap replacement for the original that worked very well.

[JJ 911SC]

Originally Posted by john walker's workshop

why not find a good bosch unit and forget the msd? it's just a cheap replacement for the original that worked very well.

John

Not that I'm complementing to switch to but is seem that a lot of people are. Could you share your insight?

Merci

J.J.

[stlrj]

Ted,

If you can see the Space Needle, could rain have been an issue?


Cheers,

Joe

[JJ 911SC]

Originally Posted by stlrj

Ted,

If you can see the Space Needle, could rain have been an issue?


Cheers,

Joe

... must be the truth. Good work Sherlock...

[stlrj]

Originally Posted by JJ 911SC

... must be the truth. Good work Sherlock...

Been watching too much House.

[teenerted1]

Originally Posted by stlrj

Ted,

If you can see the Space Needle, could rain have been an issue?


Cheers,

Joe

typical Cali question
no this thing runs rain or shine with no issues for the past 3 years
it was a sunny evening @75degrees and not a cloud in site.
these cars are meant to drive in all weather and i make sure it sees all 4 seasons

did the spark test and the 12v test that msd suggested and even tried another coil i had sitting around...looks like the box is dead.
gonna call msd to see about sending in for repairs.

[teenerted1]

so i have taken the MSD box out to get ready to send in... and i have labeled everything so i know where it goes when i get this thing back from MSD repairs

i was going to send it in since repairs was quoted as $25-95 wow thats would be a bargain compared to a new one.

so i have it all out and all the connections are off to see so i do some double checking to make sure all is where it should be and what do i see hey the ohm meter on the switched red wire is fluctuating on and off now....so i take the meter and switch it to volts...hhmmm the volts are fluctuating too....maybe i better check and re-check the connections at the ignition switch....jiggle wires around check connections seem good and all ...and go back to the plug in the back again and the thing is showing 12volts again with no fluctuations...

so for ****S AND GIGGLES lets plug that whole MSD thing in again with wires hanging loose and the box sitting on the engine tin and try it again.........
VRRRRRROOOOOOOMMMMM
yea we are back in business!!!!!!!!!!!!

so i get it back in there where it belongs and go for a little test drive.....hey i got through that intersection again and no one at the 7-11 has to duck for cover....OK good sign...get down the hill thing are loOKing good...got to the chevron fill up the tank.....starts up again...make it up the hill check it all over again...all seems to be good.

moral of the story CHECK ALL YOUR CONNECTIONS !!!!!!!!!!!

thanks all for the help