Need some ignition help.

[BobJones]

Hey Folks, getting close to starting up my beast. It's been 20 years since it ran. Have been slowly rebuilding over the last 4-5 years. Anyway at this point the wiring is done, no smoke (YAY), but have no spark. New points, coil, condenser, ect. What should I be testing? BTW the coil was really hot, and I'm not sure if it's wired right, should it be ignition switch to fuse to - neg side of coil the + pos side of coil to dist? It is a positive earth. How do I test the high tension wire from the coil. And last but not least to test for spark is the best way just to pull a plug and watch for spark? Thanks.

[mongoswede]

Hey Folks, getting close to starting up my beast. It's been 20 years since it ran. Have been slowly rebuilding over the last 4-5 years. Anyway at this point the wiring is done, no smoke (YAY), but have no spark. New points, coil, condenser, ect. What should I be testing? BTW the coil was really hot, and I'm not sure if it's wired right, should it be ignition switch to fuse to - neg side of coil the + pos side of coil to dist? It is a positive earth. How do I test the high tension wire from the coil. And last but not least to test for spark is the best way just to pull a plug and watch for spark? Thanks.

they make spark testers that you can put in the end of a spark lead...or you can just put a plug in there and touch the tab on the end of the block to the valve cover. You will know real fast if you have spark or not.

Now coil wiring....pretty basic but if you put the connectors on backwards they usually still work....but often not as well. The coil should have a ground wire and a wire going to the distributor...this switches power on and off causing the electric field in the coil to energize and then collapse resulting in the spark to the spark plug.


So check for spark first and then report back.

[disco2hse]

Easiest way to check if there is a spark is to take off a plug lead and shove a phillips head screwdriver into the plug holder on the end of the lead. Get someone else to turn over the starter and while they are doing it hold the handle of the screwdriver so that there is a small gap between the side of the metal part of the screwdriver and some earthed engine component (I usually find the radiator cap to be the easiest to get at). If there's a spark you will clearly see it jumping from the screwdriver to the engine - watch out though, don't actually touch them together, they may weld).

Note - hold the handle! Holding the metal part of the screwdriver could be a bit shocking if there is a spark :eek: On the other hand, you have positive proof that there is indeed a spark. :D

http://wikiraqi.com/images/1/15/Electric_shock.jpg

You should also do this test from the coil->distributor lead to make certain the problem is not related to the distributor itself.

If your coil is hot you may have boiled it and ruined it. How long did you leave the key on?

Easiest way to check the coil is to take it to an autosparky and have them test it.

[Nium]

If you have a 25D4 Dizzy (dome shaped cap)

Make sure you've got the low tension lead isolated from ground at the points. If you bolted the wire to the top of the points so that it comes in contact with the nut for the points post it is always grounded out. The correct order is for the low tension lead to sit directly on top of the spring for the points along with the wire from the condenser. Then a plastics top-hat looking insulator is put on (top hat side down) to isolate the low tension lead from ground (the post). Then the nut goes on top of the insulator. Thus when points open and close coil is thus energized and de-energized by points making and breaking earth connection to coil. There should be a top-hat looking insulator on the bottom side of the points spring too.

If you're not running a 25D4 check the points are adjusted and aren't always closed.

Best o luck if that ain't it and hope you get er up and runnin soon.

[BobJones]

Thanks for the help folks. I did have the isolator in wrong therefore the low tension lead was grounded. Gap was good. Great spark! Fired it up for first time in 20 years, runs great! Still have a ton of work to do but this was a great weekend.

[disco2hse]

Glad to hear it. :thumb-up:

Now some homework. :nono:

Make a utoob of it running :D

[Nium]

Glad to see you got it sorted! Gotta love the simple fixes.

Just an FYI. In running a 25D4 dizzy I've found that a lot of problems are caused by the low tension lead breaking, so if you run into a no go situation check that wire before anything else. Till then enjoy.

Cheers

[NickDawson]

Loved reading this thread! Clear symptoms, great advice and a successful resolution!

[73series88]

sweet
have fun!!