Ian7 Posted August 10, 2008 Share Posted August 10, 2008 ok, so the Super7 came home from todays blat on a flatbed tow truck... GRRRRRRRR was driving along, everything seemed normal; noticed that the engine seemed to be popping a little; over several minutes got progressively worse, like the timing was off badly, but it ran fine 10 minutes ago; eventually got to the point where I thought the dizzy had drifted or come loose; now barely running, serious jerking, coughing, etc, barely a walking speed possible, like its on two cylinders (I'm on a bridge, can't stop) finally crested bridge, coasted to a halt; bonnet off, found nothing loose or obviously wrong; dizzy still tight (wont turn by hand), cap intact, etc here's the question - how hot does a coil get? mine's in the engine bay, on the frame under carburetors, so it sees overall engine bay temps, but it was WAY too hot to touch, I mean running-engine-exhaust-header hot, not rocker cover hot... normal? (info - basically everything on the car is 5 years / 1,000 miles old; battery new this spring) let the speculation begin. cheers, Ian Link to comment Share on other sites More sharing options...
slngsht Posted August 11, 2008 Share Posted August 11, 2008 Have you confirmed fuel pressure and fuel level? Link to comment Share on other sites More sharing options...
Ian7 Posted August 11, 2008 Author Share Posted August 11, 2008 no, will check, but I've run this car out of gas a few times, and it's been a very benign "stutter-cough-quiet" shut down. yesterdays misfiring could almost be described as mildly violent, showed no sign of ending prior to ignition key off. been suggested by a responder on another forum that the points of the dizzy might have closed up, but this Aldon dizzy has an electronic box inside instead of points; anyone experience this type of problem before? fixes (short of buy-a-new-one) ? thx Link to comment Share on other sites More sharing options...
shiva Posted August 11, 2008 Share Posted August 11, 2008 I know that my turbo miata acts very violently to used/cracked sparkplugs. Not to the point of dying but still. Slight throttle and you'd feel as if in a roller coaster ride. Don`t know much about your engine, but I'd start with the basics and things that don`t cost much to swap/change. sparkplugs, plug wires and such. And if that wasn't it, you'll have a spare to use in a year or so as regular maintenance. Just my 0.02$ cnd Link to comment Share on other sites More sharing options...
scannon Posted August 11, 2008 Share Posted August 11, 2008 I think you should look at that overheated coil first. Heat like that usually means it is in melt down mode and could produce the effects you describe. Swap in a known good coil and see if the problem resolves itself. Skip Link to comment Share on other sites More sharing options...
Ian7 Posted August 11, 2008 Author Share Posted August 11, 2008 ongoing thanks... forgot to state this is a 1600 x-flow, simple as can be with exception of the mysterious (to me) Aldon electronic(?) dizzy hesitant to put a new coil on in case the problem caused the coil meltdown, then I'll have another dead coil and be no smarter... will try less expensive things first as someone suggested Link to comment Share on other sites More sharing options...
bball7754 Posted August 11, 2008 Share Posted August 11, 2008 Ian - I have a 1700 Crossflow, and several years ago on a Sunday morning drive experienced the same symptoms. Had been driving for 30-40 minutes, when it started to miss, cough, etc. I finally pulled over to take a look. Nothing loose, but if I remember correctly my coil was also extremely hot. Anyway, after about 15 minutes of primarily staring, with the occasional check to see if anything was loose, I decided to start it. Started right up, ran clean, and I've never had the problem again (famous last words - figure I'm jinxed now!). Sorry I can't help with the diagnosis. Steve Link to comment Share on other sites More sharing options...
Ian7 Posted August 11, 2008 Author Share Posted August 11, 2008 MISFIRE CURED ????? ok, so I started with the easy stuff, and found the metal tang on plug wire #1 broken off inside the boot. There's my misfire, right? Crimp on a new piece, and a quick trip around the block, and it seems fine. However, doesn't explain the stinking HOT coil (or does it? unlikely...), and secondly, wouldn't a three cylinder Kent still have enough power to drag this very light car up a very mild incline??? Link to comment Share on other sites More sharing options...
JBH Posted August 12, 2008 Share Posted August 12, 2008 Electronic components don't do well with heat. Can you relocate the coil? I think you are asking for trouble if you don't take care of it. Link to comment Share on other sites More sharing options...
Ian7 Posted August 13, 2008 Author Share Posted August 13, 2008 Been thinking about that, but with coil under the inlet manifold ('cooler' side of the engine bay), only improvement would be an air duct to it, or on the other side of the passenger footwell inside the cockpit. Ran fine for a 1000 miles, and surely other Kent engine owners have their coils in the engine bay. Link to comment Share on other sites More sharing options...
fnmag58 Posted August 20, 2008 Share Posted August 20, 2008 if you can't touch the coil, there is something wrong--a coil should be warm but not hot. As the coil gets hotter, it's capability to rapidly produce high voltage rapidly decreases. They do self destruct if there is not enough oil inside. Check to make sure your wiring connections are clean and not corroded--high resistance thru poor connections will cause this. I relocated mine to the front of the foot well--no problems with heat at all. Also check the resistor--some are external to the coil--again check for high resistance. Your coil should have a primary resistance of around 1 ohm, the external resistor should be in the 3 ohm range. Secondary coil resistance should be in the 11K ohm range. Link to comment Share on other sites More sharing options...
lowflyer Posted August 21, 2008 Share Posted August 21, 2008 You didn't mention, but is your coil mounted vertically or horizontally? Normally, they don't like being laid on their side, since there is oil inside of them to help cool them. It may have just "died" a painful death from "laying down on the job"!!!! Wow, sometimes I really crack me up! :lol: :lol: Link to comment Share on other sites More sharing options...
Ian7 Posted August 26, 2008 Author Share Posted August 26, 2008 Been away for a week. Current update: I earlier posted that fixing a plug wire made the problem go away for an around-the-block trip. Wrong!! Seems it was just the cooled coil that let it run a bit; once hot, it quit again. New coil has allowed many long drives since. Answer to previous poster - coil is vertical, and I still don't know why it fried; (maybe its Lucas and I didn't notice? :banghead: ) Link to comment Share on other sites More sharing options...
Ian7 Posted October 11, 2008 Author Share Posted October 11, 2008 #$%@$%&%$# not again !! so, maybe 200 miles after changing the coil, it appears to have fried again. latest coil was a Bosch blue, no previous mileage, but maybe 3 years old before installation. as before: coil is vertical, mounted to a chassis tube in the right-rear corner of engine bay (non-exhaust side) Kent x-flow with an Aldon electronic-points dizzy (but not a full electronic ignition) Ideas? thx (That $5000 zetec conversion I baulked at a few years ago is looking better all the time...) Link to comment Share on other sites More sharing options...
scannon Posted October 11, 2008 Share Posted October 11, 2008 I'm not familiar with the Alden distributor but in the pre-ECU days of distributors and coils, the coils for 12v cars actually ran on 6 volts using a ballast resistor. During the time the key was turned to Start, the ballast resistor was bypassed and the coil received 12 volts to facilitate good spark during starting. If you system is of this type, is there a chance that it was wired up without the ballast resistor and the coil is getting 12 volts full time? That would certainly overheat the coil leading to failure. Skip Link to comment Share on other sites More sharing options...
Ian7 Posted October 11, 2008 Author Share Posted October 11, 2008 Thx. In such a system, what would that ballast resistor look like? where typically? Given the erroneous mix of components that came from Caterham, this might be the real answer. (Ordered a kit for a Kent, received mostly bike-engine-intent components...) Link to comment Share on other sites More sharing options...
yellowss7 Posted October 11, 2008 Share Posted October 11, 2008 I remember ballast resitors. My wife had a 74 Dodge Dart with a slant six. Ballast resistor failure was common on those. Damn I'm old. :cuss: Sorry for the hijack Ian. I seem to recall that it did look something like this. Tom http://store.summitracing.com/egnsearch.asp?N=400304+309776+115&autoview=sku Link to comment Share on other sites More sharing options...
scannon Posted October 12, 2008 Share Posted October 12, 2008 That's what I remember them looking like. There may be other configurations available. You may need an ignition switch that is configured for the ballast resistor. You need to have two wires powering the coil, one for the ON circuit that goes to the ballast resistor and a second one from the Start position that goes directly to the coil. I dumped the factory Caterham ignition switch and steering lock under the dash and installed a switch from a 70s Chevy truck up on the dash surface. The first time I tried to start the car with the new switch it would sometimes fire up after I had spun the engine up on the starter and then let go of the key. When the key went to the ON position the engine would fire before it stopped spinning. I had to jumper around the provision for the direct to the coil 12v to make it work correctly as the switch was not feeding the coil directly when in the Start mode. Skip Link to comment Share on other sites More sharing options...
locostv8 Posted October 12, 2008 Share Posted October 12, 2008 Sometimes the balast is a resistor wire. Link to comment Share on other sites More sharing options...
Ian7 Posted October 12, 2008 Author Share Posted October 12, 2008 scannon said: "the coils for 12v cars actually ran on 6 volts using a ballast resistor." so what's the difference then between these "12volt" coils I keep frying, and the "6volt" coil on my friends 1965 VW Beetle ? Link to comment Share on other sites More sharing options...
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