No spark! Options

[Steve73]

I'm trying to bring a dead 914 back to life. I have done the usual prep work and have hooked up the electrical system. The car turns over strongly but there is no spark! No spark at the plugs, no spark at the coil. I have switched the coil out with one I had laying around but i'm not getting any better results. Could it be the voltage regulator located in the box where the fuel injected controls are? (mine has been converted to dual carbs BTW).

What should I try next?

Thanks in advance!

[Prospectfarms]

Unlikely you have two bad coils. A good coil may not show spark if the condenser is bad, the distributor has no continuity, or the points are bad or are not closing properly. With a mechanical distributor, points and coil ignition, it's commonplace to not get spark at plugs or HT coil wire because of some problem with the distributor points, condenser, or terminal connections thereof. The trouble shooting procedure is the same for any old car. The following is my version of the "looking for spark" dance.

Check the current to the coil at the coil+ terminal: Ignition on, test current with a test light or meter between coil+ terminal and ground. If no current at coil+ terminal, trace supply wire back to regulator plate (box full of relays and terminals on left side of firewall) if your car still has it. If it was removed when car converted to carburetors you'll have to trace the wire powering the coil back to its source--ultimately the ignition switch.

If you have juice at coil+, raise just one of the rear wheels and place car in 4th-5th gear. Check if current is passing through the distributor body, condensor and points by testing the negative terminal of the coil to ground while rotating (This feature is unique to lightweight rear wheel, mid or rear engine cars.) the engine. Disconnect the high tension (center) lead from the dist. just to be safe. You should see momentary current at coil- as the rotor turns, opening the points.

If you do not have a test light or meter, you can still check the distributor and points continuity in a similar way by removing the distributor cover and looking for a faint spark at the points every time they open.

If it seems that no current is passing through distributor as you turn the rotor replace points and condenser. If that doesn't help, check to see if the tiny braided ground strap inside the distributor is intact. It provides continuity between the advance plates ("floor") of distributor and the distributor body. Many members of this board, including yours truly, have experienced that ground strap to break, rendering the distributor inoperable. It's about the same diameter as a piece of yarn and approximately 1 1/2" long.

Good luck

[Steve73]

Unlikely you have two bad coils. A good coil may not show spark if the condenser is bad, the distributor has no continuity, or the points are bad or are not closing properly. With a mechanical distributor, points and coil ignition, it's commonplace to not get spark at plugs or HT coil wire because of some problem with the distributor points, condenser, or terminal connections thereof. The trouble shooting procedure is the same for any old car. The following is my version of the "looking for spark" dance.

Check the current to the coil at the coil+ terminal: Ignition on, test current with a test light or meter between coil+ terminal and ground. If no current at coil+ terminal, trace supply wire back to regulator plate (box full of relays and terminals on left side of firewall) if your car still has it. If it was removed when car converted to carburetors you'll have to trace the wire powering the coil back to its source--ultimately the ignition switch.

If you have juice at coil+, raise just one of the rear wheels and place car in 4th-5th gear. Check if current is passing through the distributor body, condensor and points by testing the negative terminal of the coil to ground while rotating (This feature is unique to lightweight rear wheel, mid or rear engine cars.) the engine. Disconnect the high tension (center) lead from the dist. just to be safe. You should see momentary current at coil- as the rotor turns, opening the points.

If you do not have a test light or meter, you can still check the distributor and points continuity in a similar way by removing the distributor cover and looking for a faint spark at the points every time they open.

If it seems that no current is passing through distributor as you turn the rotor replace points and condenser. If that doesn't help, check to see if the tiny braided ground strap inside the distributor is intact. It provides continuity between the advance plates ("floor") of distributor and the distributor body. Many members of this board, including yours truly, have experienced that ground strap to break, rendering the distributor inoperable. It's about the same diameter as a piece of yarn and approximately 1 1/2" long.

Good luck

Thanks Prospect, I have extra points and condensers sitting around, most brand new though they are meant for my 71 bug. I just put all new electrical engine parts in my bug this spring, set the gap for the dwell and timed it. That car has a Bosh 009 distributor which I believe is the same as what is currently in my Porsche. I'll start investigating using your advice. I have the Haynes manual but it's not so good at helping you trouble shoot something that's not obviously wrong.