Mr. 856 170 #1 Posted March 21, 2014 Is it possible to "cook" a coil if the + wire was hooked up and left on with voltage going to the coil? I know mysteriously have a no spark issue after having the engine running. I left the battery connections hooked to the coil overnight after test start. Battery went dead.....charged it. Tested it. Hooked back up to engine and now I have no spark...........did I cook the coil? I manually starting with rope so its hard to do any testing with two hands one pulling a rope. Share this post Link to post Share on other sites
sorekiwi 761 #2 Posted March 21, 2014 Yes you can cook a coil by leaving it on. I have seen it happen. But I have also seen the ignition left on and the coil was OK as well. One of these is a great tool: http://www.amazon.com/Lisle-20610-Inline-Spark-Tester/dp/B0002STSC6 TT told me to get one years ago, and I use it often. 1 Share this post Link to post Share on other sites
jimt1971 237 #3 Posted March 21, 2014 Yes the coil can get cooked if the points are closed. Share this post Link to post Share on other sites
dodgemike 52 #4 Posted March 21, 2014 Yes. Dont ask me how I know. Left the ignition on in my old Dodge and cooked the coil, the mag. pickup in dist. and ballast resistor. Worst part is I have a battery cut off switch. That was an expensive episode of CRS. Oil litetally bubbled out of the coil. Sent from my SCH-S720C using Tapatalk 2 Share this post Link to post Share on other sites
Mr. 856 170 #5 Posted March 21, 2014 would I have any spark if the coil was cooked? I can get it to fire on spray......wont stay running though. this is a fresh rebuild and it started on the second pull after I figured out I had to have the coil powered up. I shut it down and restarted it again and it ran for 10-15 minutes. I changed the fuel pump to carb line out with a solid one instead of the soft material I had there. Now she wont fire off. Really wish I had a buddy that would give me a hand. I need more the two eyes and hands to figure out what's going on. Where to start? make sure fuel pump is pumping? I know I have spark for it to fire on spray. Im assuming the coil is still good.. Share this post Link to post Share on other sites
pfrederi 17,642 #6 Posted March 21, 2014 Get a $4 spark plug tester and see if you have spark. Share this post Link to post Share on other sites
WH nut 553 #7 Posted March 21, 2014 Get a $4 spark plug tester and see if you have spark. Or save 4 bucks and pull the plug and lay it on the head and spin her. Share this post Link to post Share on other sites
pacer 3,168 #8 Posted March 21, 2014 Well, that certainly is the common description of a fuel problem - will run on spray and wont without. Since you did work on the fuel system just prior, then retrace your steps, something must have changed. 1 Share this post Link to post Share on other sites
Coadster32 793 #9 Posted March 22, 2014 There was a post a few years back that someone caught their garage on for by leaving the key on. I guess the oil in the coil caught on fire. I take my keys out when I park them. (keeps the kids from getting into trouble as well.) Share this post Link to post Share on other sites
specialwheelhorse 174 #10 Posted March 25, 2014 They will also EXPLODE. Halfway to the track with our dirt track car years back some fool left something ON ( likely me ) and BOOM sound like a shotgun, no problem just a basket of wire and oil everywhere. A darn good thing no one close, it would not have been pretty !!! Share this post Link to post Share on other sites
tunahead72 2,400 #11 Posted March 25, 2014 Chris, this may be the thread you were talking about... Share this post Link to post Share on other sites
