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trying to resurrect..no fire.....

.....Ignition box is whining away--no power to coil..What do i test next?? Hmm one issue at a time and i will get this thing fired one day!!!

thanks guys

Hi,

Welcome to one of hte best BBS for air cooled porsches. help us out a bit by adding your location to your profile and tell what year/model 911 you have.

This thread may be helpful: http://forums.pelicanparts.com/porsche-911-technical-forum/528944-ignition-problem-troubleshooting-electrical.html

Also, from another thread (http://forums.pelicanparts.com/porsche-911-technical-forum/449527-how-do-i-check-coil-timing-light.html):

Quote:

Originally Posted by HarryD (Post 4395758)

To get a spark to the spark plug in the engine. Several things need to happen. First, you need power to the CDI. Next you need to have a way to trigger the CDI (the points do this by opening and closing). Then the CDI will then send a pulse to the coil which will increase the voltage and send it through the high tension lead to the rotor and to the selected spark plug. You need to verify that each step in this chain is working.

1) Verify that the CDI is getting power. Do you hear it wining (if it is a Bosch unit)? If so, you are good to go.

2) Verify that the CDI is producing power to make a spark. You can do this with a "telegraph" test. Take the high tension lead off of the center of the distributor and put a spark plug on it. Ground the threaded part. With your plug attached to the center lead, open the distributor, remove the rotor, place your key in the run position, and manually open and close the points. Each time you cycle, you should see a spark from the plug. If you do not, you may have a bad CDI.

3) Verify that the coil gets a signal when you crank. Replace the rotor and distributor cap. Leave the plug on the center high tension lead. Crank the engine. Do you see a spark? If so, you are getting spark to the distributor. If not, your point gap may be off or there is some other problem with the connections.

4) Verify that the spark goes to the spark plug wires. Reattach the center lead to the distributor. Attach you spark plug to one of the leads going to the cylinder spark plugs and ground. Crank engine. If you see a spark you may have a timing problem. If no spark, you have a problem with your rotor or distributor cap or your wires are improperly seated.

Do a search here as there are many threads on this topic. Look especially for the ones by early_s_man. Warren (RIP) left a great deal of knowledge on troubleshooting this problem.

Wow what great help --thanks... I do hear the wining from the CDI but it doesn't seem the coil is getting the signal. Still doing some checking..Also, with key in run position there is no voltage getting to coil. BAD CDI??

thanks again

indasevens,

You really have to tell us what kind of car you are working on. The ignition systems changed quite a bit from the 60's to the 70's and into the 80's and 90's.

In general, you cannot measure voltage at the coil if you are using a CDI box.

so sorry....I have a 71 911t. Hasnt run for several yrs.

Do you have points or some type of electronic breaker on the distributor?

indasevens,

You should have a 3-pin CDI just like mine. Hearing it whine is a good first step, but the instructions HarryD has shown are the basic ignition checks you will have to make. In particular:

2) Verify that the CDI is producing power to make a spark. You can do this with a "telegraph" test. Take the high tension lead off of the center of the distributor and put a spark plug on it. Ground the threaded part. With your plug attached to the center lead, open the distributor, remove the rotor, place your key in the run position, and manually open and close the points. Each time you cycle, you should see a spark from the plug. If you do not, you may have a bad CDI.

This is an excellent test of the CDI, and combined with the other instructions, should lead you to a working ignition system.

Best of Luck.

I think i simulated that test by checking spark from coil when turning motor over and did not get spark---I check under the cap and the "points contact was actually breaking so.......still searching..Maybe i didnt perform test properly though

Don't overcomplicate. When troubleshooting, a stepwise approach is best and will lead you the end most effectively.

Do the "telegraph test" as I stated to remove any extraneous factors.

YOU GUYS ARE GREAT!!! Did the test and the spark plug "lit" everytime the "points" broke contact.....Getting excited here...now what???? LOLOLOLOL

NO SPARK on second test...only when i manually break "points"..Turn motor over and no spark..

OK guys let me explain more....I did the first test and got spark..but realized it was because my little screwdriver was touch other "areas" and causing the spark to the plug..when i move the distributor enough to just break the point it doesn't spark.....hmm not sure what that means--

Have you set your point gap correctly? Gotta ask, sorry.

Never "set" them but just got done cleaning the contacts and GUESS WHAT..spark..all the way to the spark plugs...Once i get it running and know it at least runs. I will go back and invest in new wires, cap rotor, etc, etc,

thanks again guys

Quote:

Originally Posted by indasevens (Post 5221750)

Great to hear! Sometimes it is just the little things...

Let us know how she runs.SmileWavy

I'm surprised no one has mentioned fuel. Is this new fuel or old? Did you dump the old or just mix it with new? The old fuel could give you a hard start or no start at all. Just something to think about.

OK spun it over for first time and NOTHING.. I hooked up a temporary fuel lines with fresh fuel in it. Again, once i hear it atleast run then i will go through all steps of flushing tank and all lines.

Every once in awile it acts like it wants to start but still nothing. Its one step at a time i guess!

Set point gap and set static timing @ TDC to see if she will start.
Be sure the clean fuel is actually going into the carb throats.
If she starts and runs, set timing to 35* BTDC@6000rpm.

Your car should have originally come with Zenith carbs. Do you still have carburetors on it? If so, they may need a good cleaning from not have run for many years.

YES the zeniths are still on it. I guess i need to rebuild them huh....ARGGGG