lcbusa1300 Posted December 9, 2013 Share Posted December 9, 2013 Friday I was making the 1 1/2 hour trip home from college. About 40 minutes into the trip, it died going down the interstate. No missing, or sputtering, it just completely shut off. While rolling i pushed the clutch in and tried to start it but it would crank but wouldn't start, so I eased over onto the shoulder. I could smell a plastic burning smell. I popped the hood and looked to find my battery had fallen over and the post was touching the valve cover. So I repositioned the battery ( is now secured to its spot ) and it started right up. Thought maybe it had caused an electrical issue. Problem solved. I drove it the rest of the way home and around town all weekend with no issues. Well it was time to make the trip back to school this morning for finals. 40 minutes into the trip, it did the same thing, but the battery was still in its spot. I had someone take me to my final, and I came to get the car afterwards. It started right up and made the rest of the trip just fine. I've been reading since this morning and can't find anyone with a similar problem. Everyone's symptoms include the car misfiring or not running properly. Mine runs great but something is completely shutting the car off after about 40 minutes. Once cooled down it'll start and run great for a while. Anyone have any ideas? BTW, the car is a 78 280z fuel injected 5 speed with N47 head. I installed a MSA header and exhaust a few weeks ago, deleted the EGR, and removed the heat shield while I was there. Quote Link to comment Share on other sites More sharing options...
NewZed Posted December 9, 2013 Share Posted December 9, 2013 Watch the tachometer. If it goes directly to zero while you're coasting in gear with no power, it might be the ignition module. Just one clue, it could be some other electrical component that is overheating and killing power to the ignition also. Quote Link to comment Share on other sites More sharing options...
lcbusa1300 Posted December 9, 2013 Author Share Posted December 9, 2013 (edited) That's exactly what it does. Tach went to zero. My ole man told me it was probably an ignition module, but after seeing how much a replacement is I was hoping someone would tell me different. But I don't think the burning plastic smell could be result of that? Right? Edited December 9, 2013 by lcbusa1300 Quote Link to comment Share on other sites More sharing options...
JMortensen Posted December 9, 2013 Share Posted December 9, 2013 You don't need to run the factory module. Pretty much any module will do. I had a friend with a 280Z distributor who ran a Chrysler module out of a van with a 318. You will need to figure out how to wire a different one, but they're pretty simple and it shouldn't be hard to find a generic schematic online. IME, your symptom is a classic module fail. Runs fine, dies instantly. Cools off, runs fine again. Quote Link to comment Share on other sites More sharing options...
lcbusa1300 Posted December 9, 2013 Author Share Posted December 9, 2013 Nice, good to know. Ill get to looking. Quote Link to comment Share on other sites More sharing options...
NewZed Posted December 9, 2013 Share Posted December 9, 2013 The initial burning plastic smell was probably your ground cables getting hot when the battery post touched the engine block. Even the big negative cable is only designed to carry the amps returned from the starter, not a straight short. The module might have seen some stray current when the big short happened and been damaged. Electronics don't like extra current or voltage. Or it could just be coincidence. Quote Link to comment Share on other sites More sharing options...
lcbusa1300 Posted December 9, 2013 Author Share Posted December 9, 2013 Good point, but I smelled it the second time too. I forgot to mention that. Quote Link to comment Share on other sites More sharing options...
NewZed Posted December 10, 2013 Share Posted December 10, 2013 The stock module is in the cabin, along with a few relays. Stick your nose down by the fuse box and see what's going on down there. Quote Link to comment Share on other sites More sharing options...
lcbusa1300 Posted December 11, 2013 Author Share Posted December 11, 2013 I took it to school and back today (~30 min) and it did it again. Ran great until almost home and just completely shut off. There was no smell this time though. The weird thing is, It starts right back up, goes about another mile then does it again. So it's about impossible to test for lack of spark or fuel or anything for that matter when the car starts right back up. I've searched and I can't find much on replacing the Ignition control module with one other than factory. Also, I dont trust myself with electrical components, and I've never touched a soldering iron. So, if installing a ICM from a different vehicle requires anything other than plug and play, I wouldn't feel comfortable. I know I should man up and do it but this is my DD and I don't think I should be experimenting. I guess I'll try and hunt a replacement down and just keep my trips under 30 minutes for the time being. Quote Link to comment Share on other sites More sharing options...
NewZed Posted December 11, 2013 Share Posted December 11, 2013 Modifying for a different module isn't plug-n-play, there is some wire cutting required, and probably some hole-drilling and minor fabricating. Check RockAuto.com. Click on the part number and you'll see a cross-reference to all of the vehicles that used it. Maybe you'll find a used one. Over $100 otherwise. Quote Link to comment Share on other sites More sharing options...
lcbusa1300 Posted December 11, 2013 Author Share Posted December 11, 2013 Good deal, Thanks. I've found a couple used for <$100. Quote Link to comment Share on other sites More sharing options...
lcbusa1300 Posted December 13, 2013 Author Share Posted December 13, 2013 Update: Made the trip back home from school today for the holidays. 40 minutes on the dot, it surged/bumped a couple times then shut off. I could smell the burning smell again this time. So I eased over to the shoulder, stuck my head down by the transistor unit and couldn't smell anything in that area. While I was down there I noticed the transistor unit looked brand new… shiny black with white letters. I can't get in touch with the previous owner to find out if it was replaced. I noticed this time, when it shut off, the Ebrake light started flickering. This time, I didn't even let it cool. I immediately started it right back up and it ran for probably 40 more miles and did it again. I'm so puzzled. Quote Link to comment Share on other sites More sharing options...
lcbusa1300 Posted January 8, 2014 Author Share Posted January 8, 2014 Still haven't been able to find the issue. It's happening more frequently now. Also, now my dash lights have quit working and my park brake light stays on. A few have told me those sound like symptoms of an ignition switch. That's a cheaper fix than the rest so should I try that first? Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 8, 2014 Share Posted January 8, 2014 On my 76 the instrument lights are on the same switch as the tail-lights. If your instrument lights are out, tails might be too. Save yourself a traffic-stop and check. I've seen some rusty relays over by the fuse box though on my car. A bad relay overheating and opening up might explain your symptoms. The main ignition relay is where I would start. You can't really tell that they're bad from the outside. I've attached a picture of mine, which had been bypassed when I got the car. Quote Link to comment Share on other sites More sharing options...
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