reasons for no spark

[dagimp]

OK. One day my Thing wouldn't start. It cranks strong, but doesn't even sound like it's going to catch and start up. After running a few tests, I determined that there is no spark from the coil and when cranking the engine, my test light doesn't flash when put on the negative side of the coil. I tried a few different coils which all had good resistance (3.9ohm and 3.5 ohm between the +and -; and 9000 and ~10,000 between the + and center plug). I even tried to replace my electronic 009 dizzy with a dizzy with points (same cap and wires though) but to no avail (BTW, I have no idea whether the new dizzy was even installed correctly because I don't have any experience with these). I'm clueless as to what else the problem could be or whether there are any other procedures I should follow to get her started. Thoughts? Thanks a bunch.
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Buck

1973 Orange VW Thing, "Otto".

[Towel Rail]

A couple things I'd do is check to make sure that the coil is getting 12V to begin with, all five of the plug wires have continuity, and that they're clean and solidly plugged-in. Perhaps the main plug wire came loose from the coil?

Since you mentioned that the problem just happened out of the blue, we can probably rule out the plug wires being hooked up wrong.

Hope this helps,
- Scott
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1974 Thing -- under the knife
1967 Beetle -- spring/summer/fall driver
1996 Subaru OBW (EJ22, 5-speed, AWD) -- winter car, 3-seasons "don't feel like biking today" car

049 > 070 > 053 > 009

[tallman206]

1) First, you need to test that you have 12V at the + or Terminal 15 of the ignition coil with the ignition switch on. Use your test light to see if there is power there. Good? Continue. . .

2) Next, check to see if the power is going through the coil. Remove the distributor lead (and any other leads) from the negative or Terminal 1 of the coil. Check for power at Terminal 1, there should be power here now with the distributor lead disconnected. Good? Continue . . .

3) Connect the distributor lead back to the coil and see if there is power (light) or no power (no light) at terminal 1. If there is power, then the points are open or electronic ignition module is open circuit. If there is no power, then the points are closed, or the electronic ignition module is shorted. If you cannot get the test light to flash on and off when the engine is rotated, then the problem is in the distributor.

4) By the way, is the distributor even rotating when the engine cranks?
If you don't get the distributor seated fully, the distributor won't engage the drive gear and rotate, and the points will not open and close.

5) IF this is not the issue, and if you find that the points appear to be permanenty closed, you can also look for a short in the intermal distributor wiring or condenser, or perhaps the points are bad or mis-adjusted to be permanently closed. If the points are permanently open, it could be that the points are bad and do not close to make circuit.

6) You can make a basic test of the distributor points (not an ignitor module) when you have the distributor in you hand by connecting an ohmmeter between the distributor body and the distributor lead. Rotating the distributor should cause the ohmmeter to show open and then shorted as you rotate the shaft.

Hope this can help.
Tallman206

[dagimp]

Thanks much for the tips. After checking the above info in the two posts without any luck I changed back to a different coil and it started right up.... However, after poking around, I realized that I hadn't hooked up my tach. When I attached it to the - on the coil, the engine immediately started to die, so I took it off and the engine started running normally again. I went to my tach and realized that I had used it's ground wire to ground a light I had just installed. I removed the ground wires from the tach and attached the wire back to the coil... engine ran as normal. I'm guessing the wire from the - coil to the tach must have been grounded so no current was getting out from the coil.

Unfortunately, I think I fried my tach somewhere along the line because even when setting it up as before, it doesn't work. I checked the wire from the - coil to the tach with a test light and it's blinking as it should be. However, the tach still doesn't work. Man, what a pain. I don't suppose anyone knows how to revive a fried tach?
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Buck

1973 Orange VW Thing, "Otto".

[TKE381]

I am not getting any spark from the coil. I checked the + terminal on the coil and got nothing. I disconnected the 12v lead from the + side and tested it while not connected - Got 12V from the wire.

So reattached to the coil and got nothing. Rotated the engine, still nothing on the + side of the coil.

Switched out coils, same problem. I recently added electronic ignition with a SVDA 034.

Any ideas???

[TKE381]

OK - This morning I ran a jumper from the battery to the coil - Fires right up.

So I went to the fuse block. Had conductivity in the wire. 12 volts in the block. Could it be as simple as just needing a new connection (sure is dirty in there). Wa La - started right up with just one little problem.

Now my parking lights have to be on for the car to start / run.

I did not move, disconnect, or change anything. Any ideas???

[nwflvw]

I had the same problem once. The tail light wire is probably shorted to the hot wire to the coil somewhere in the harness. I always fuse the hot lead to the coil in the engine compartment of my own cars If something shorts out in the engine compartment it just blows the fuse and doesn't ruin the harness. Vince

[TKE381]

That's it! Thanks! And I will be fusing it from now on. Anyone have a source for the main harness other than TS?

[doublecanister]

You know,

I ran into this similar issue on my old 66 Mustang, in my case the pertronix ignition was burnt out from Leaving the Key in the ON position too long (while I was testing interrior light issues).

I noticed (while troubleshooting this)that on the Mustang the Tach was part of the ignition circuit, which, if the tach failed, or was just unplugged from the circuit, the car wouldnt start.

I'm not 100% on VW's with this wireing method, but if it's the same, or in the case of a home install,

Wouldn't a road side workaround be a good idea? Some way to jump out the tach to keep the car's starting circuit in place??

I've been mulling a Tach install on my THING, and this as always bugged me (At least with how it was on the Stang) with using a tach at all.

Anyways, just stuff for thought.

Glad you got her fixed up TKE381.
T
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2020 - Mustang Eco Boost [High Performance]
1973 - Thing
1966 - Mustang GT- Fastback
1951 - Ford F1 pickup Flathead V8

[Augsburg57]

My engine in my '67 bus had run great and then I had tune-up by a shop prior to a road trip. About 50 miles out on the road I noticed the engine missing when climbing a long hill. Hmmm. Then another 100 miles and more hills and the missing gets worse and worse. Finally I turned around and headed back home. Limping along. Sometimes runnning OK, sometimes missing under load.

My first thought was it was an ignition problem (maybe bad points or condenser installed in the tune-up?), but the shop thought the problem might be the fuel pump. They put in a new fuel pump and now the engine dies at stops. I pulled the pilot jet out of the carb and blew it out. Vroom! The engine runs great again.

But not for long, it stops dead - stranding me at a local dog park with my two Great Danes on one of the only two or three days a year it gets really hot in Seattle. Dogs are panting. I'm sweating in the sun. Finally give up after troubleshooting several false leads when I determined no spark. Towed it to the shop. Of course, the next day when the shop opened, it started right up for them. Hmmm.

I drive the bus home and it is running great. Then later that day, it stops dead again. Sure seemed like a fuel problem this time. Lots of sputtering and loss of power before it gave up the ghost. More playing with the carb. Claning the pilot ject has no impact. Then, check the timing with a test light. It's dead on and the test light shows the points are opening and closing. Is the carb full of dirt? Do I rebuild. Ah heck. I replace it. No go. Still does not run. Hmmm.

I think to check the plugs again. Now they are black and sooty. Hmmm. Check the spark at the coil wire. Weak and yellow. Check the spark at the plugs. No spark. Hmmm. Is the coil bad, is the distributor cap or rotor bad?

More troubleshooting. I keep checking all the things in the list for no spark. I search through the forums with subjects of "no spark". I check all the helpful troubleshooting links mentioned in the forums. I have power at the coil when the key turns on. The carb solenoid clicks on and off with the turn of the key too. The test light showed the points open and close. But then - while looking at the distributor I notice something underneath. Ahah! The condensor wire is pinched in the clamp that secures the distributor. (Remember the trouble started after a tune-up.) I pull the pinched wire out of the clamp. Wire strands can be seen through the squashed insulation - it was grounded. The engine still does not start - even with the condenser wire freed from the clamp. Did the ground burn up the condensor or the points? I replace the points (which are pitted) and the condensor.

Eureka! Starts first crank . . . .
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'67 VW 11-Window Standard Bus, 2027cc Stroker with Dual 40 IDF Webers

[doublecanister]

[Scorcho]

[mondshine]

With one of your test light leads connected to Terminal 15 at the coil, and the other lead connected to ground, the test light should be illuminated with the ignition switched on.

Next, disconnect the green distributor wire from Terminal 1 on the coil.
Now, with one of your test light leads connected to Terminal 15 at the coil, and the other lead connected to the green wire, the test light should be illuminated whenever the points are closed. With the engine cranking, the test light should be on-off-on-off, etc.

Think if the ignition points as a momentary switch to ground. Each time the green distributor wire's connection to ground is broken, a spark is created.