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-   -   1971 spark issue (http://forums.pelicanparts.com/porsche-911-technical-forum/590277-1971-spark-issue.html)

porsche189 02-07-2011 07:43 AM

1971 spark issue
 
I am trying to run down the issue, but it seems to be running me down faster. Any advice would be greatly appreciated.
New Coil and Permatune electronic ignition, new alternator
New plugs, wires and points, only thing i haven't replaced is the distributer. (will it make a difference if it is turning as it should?)
Ran for a day or two, adjusted timing and then sat for 2 days and wouldn't start again. Same issue... ignition is not receiving signal from distributer, and coil not getting power. Checked for ground loop problems with an ohm meter.
Before buying everything again.
Where should I start investigating?
Steven

BK911 02-07-2011 07:56 AM

Points. Verify gap. Get running, then set dwell.

kodioneill 02-07-2011 08:08 AM

Sometimes the little insulation block on the side of the distributor shorts to ground if the fiber block is broken up. Check that connection closely.

porsche189 02-07-2011 08:12 AM

Thanks I will try that

Dick Shift 02-07-2011 08:13 AM

Re: ignition is not receiving signal from distributer.

Make your own signal.
Key in "ON" POSITION. Remove the PRIMARY [small ]wire to the dist. hosing, and scratch along some matalic part. if the dist. is not doing it's opening and closing of the primary curcut it will now have a spark.

Dick Shift 02-07-2011 08:24 AM

Re: and coil not getting power?

Coil gets PRIMARY voltage via the CD when key is in on position. Ck with volt meter @ 5+ volts at + or A on coil.
Basically - side of the coil just goes to dist to be an open or closed to ground curcut. Resulting in a build up or secondary higher SECONDARY voltage exciting the coil to be distributed to the spark plugs. On Porsche w/ CD the ground is run threw the CD.
Hope some of this helps!
Aloha,
DS

T77911S 02-07-2011 08:45 AM

the points (gap) is not that critical on these cars. as long as they open and they close, they work.
first, permatunes are not that good. if you want something cheaper than the bosch but good, go with MSD., but lets get it running first.

here is what you have to have to get spark.
you need 12v on pin B. i recomaned a test light. a MM will not let you know if you have a good connection, only that 12v is present. test the light at the battery, that is about how bright it should be at the CD.
you need a good ground connection from the CD unit to the neg side of the coil and to the engine if you have the coil grounded. measure resistance from neg coil to CD unit and engine to CD unit. should be close to zero.
the C input to the CD is the trigger. that is the ground provided thru the points-dist-engine back to the CD unit.
make sure all this is good.

pull a plug wire and connect a spakplug to it. place it against the engine. (do not hold it).
have someone crank the engine to check for spark.
if no spark, pull the coil wire out of the dist cap, place it (do not hold it) close to the engine block. have someone crank it and check for spark. if still no spark, you can also apply ground to C and remove it at the CD unit to make it spark if the crank test does not work.

one of the things i do every so often is remove my dist and clean the housing on a wire wheel on the grinder. i also clean the screws that hold the clamps and the clamps to make sure i have good grounding through the dist to the engine block.
the points wire connects to one of those clamps. they get pretty rusty and can cause problems.
this is a very simple system. not a lot needed to make it work. you just have to have electrical continuity between all the parts, grounds and voltage sides.

porsche189 02-07-2011 09:32 AM

the coil still doesnt have any power, I checked the gap and it is .012. The coil is getting nothing still.

porsche189 02-07-2011 10:09 AM

Its not getting a signal, i will clean the distributer

Walter_Middie 02-07-2011 11:22 AM

Quote:

the coil still doesn't have any power
You cannot check for voltage at the coil - it doesn't work like that with a CDI system. You need to follow the troubleshooting described by T77911S.


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