QuestionQUESTION: I have a 1967 Austin Healey Sprite (Positive Ground) that I am trying to get on the road again. It was garaged and not driven for about thirteen years. When it was put away it was running fine and it was started occasionally and so on. About two months ago I decided to get it running again, so I bought a new battery, drained old fuel and filled with new high octane. I pulled the engine through to be certain that nothing was sticking or seized. I cleaned the plugs and started attempted to start it. The engine initially did not start, but did fire (spark) at that point. It started briefly on the starting fluid sprayed in the carbs.
I determined that it was not getting fuel and decided to replace the fuel pump. This was done with a generic aftermarket electric pump. The car is wired positive ground, so the fuel pump had to be wired up with the polarity reversed, as it were, with what would normally be the ground hot and vice versa. Fuel pump works fine and it is getting plenty of fuel. It turns over just like it always did. However, now, I can get no spark.
I have replaced the points and condenser, distributor cap, internal distributor ground strap, rotor, and plug wires. Still now spark. I have also replaced the coil with a generic aftermarket coil and wired it for positive ground with the negative lead to the solenoid and the positive lead to the distributor. Still nothing. Test lamp indicates power going into the coil. However lead to the distributor shows nothing, even when engine is motored over with the starter.
I there is no spark visible in the points, nor from a plug when grounded against the block and the starter is turning. I have basically run out of ideas as to why there is no spark, as there is not much left to be replaced. Even if the distributor is 180 degrees out, there should still be a spark and I have none.
I have worked on all sorts of cars, positive and negative ground and a fair number of British ones (Mostly M.G. and Austin-Healey) for over thirty years and have never run up against anything quite like this. A bit baffled at this point and out of bullets (so to speak) to shoot at this problem.
HELP PLEASE! Any suggestions or insight will be most appreciated.
ANSWER: Oh dear! I'm a bit baffled too, but let's try.
Let's return to the fuel later. Your first priority is the lack of spark. You must have a testing light or voltmeter for this. A few thoughts, possible problems...
1) The negative coil terminal should be a white wire from the ignition switch and go live when you turn on the ignition. If you've wired the coil direct to the hot (battery) terminal on the solenoid, it's possible you've melted your new coil, since it will always be live and passing current if the points are closed. (Similarly, you generally shouldn't leave the ignition on for long when the car is not running for the same reason.)
2) The other wire (probably white-black), on the positive terminal, is the low-voltage line to the distributor.
3) To test the spark from the coil, disconnect the high-tension wire at the distributor cap. Turn the engine over by hand until the points are closed and turn on the ignition. While holding the HT lead close (1/4 inch, say) to the block, flick the points open with your finger. You should get a good spark.
4) If you do get a spark, reinstall the wire and the cap and repeat your test of holding a spark plug to the block while cranking the starter. If the first test (#3) makes a spark and this test doesn't, and assuming that you have the right points gap (0.015 in), the problem is inside the distributor. Particularly suspect the graphite bushing and spring in the cap. The bushing (looks like a short piece of pencil lead) must move freely in and out.
[Something I know nothing about: some coils are not suitable for capacitor (ballasted) systems, so you might also try disconnecting the capacitor.]
5) Also suspect the two little nylon spacer/washers that insulate the incoming low-tension wire, the points spring and the capacitor connector from the threaded post that they mount on. Is it possible you dropped one when you changed the points? They must be live when the points are open.
6) If all else fails, there's a quite good pair of Moss Motors YouTube videos linked from the Moss web site about how to check ignition problems. www.mossmotors.com.
Hoping that you get that working, fuel next...
I'm glad the pump is working, but after that long in storage you must take the float chamber lids off (floats still attached), clean out the chambers (lint-free rag and a blunt pencil), and check the float valves. It's possible that one or both needles are not opening. For each one, with the aid of a helper, turn on the ignition and jiggle the float up and down. Fuel should pour out when down and stop completely when closed. That will clean them as well anyway. Check the paper gaskets when you replace the lids.
SU jets don't usually get blocked, since they open quite wide. But if the car starts, but dies when you open the throttle, write again.
And definitely put 2 cans of fuel injector cleaner in the tank; though note that that might release more crud from the tank and the lines, and necessitate cleaning again!
Good luck!
Jo
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QUESTION: I doubt that the coil is damaged, as it is wired up exactly as the old coil was wired and always had been since I have owned the car. 99% sure that points are installed correctly with bushings. The distributor cap is brand new from Moss Motors and has good action on the bushing. (I did suspect the bushing on the old one.) I am now suspecting the capacitor as you noted. One other possibility that I have wondered about, though is that there seemed to be plenty of spark until I changed the fuel pump. I am wondering if I have somehow incorrectly grounded it and/or the chassis in doing so and now it is more or less like pouring water on a fire. I have heard of this happening with positive ground systems, although I have never personally dealt with such an occurrence.
Unfortunately, I will not have a chance to check this out for a few days, as I am changing a water pump and air conditioner compressor on one of my Buicks in the interim and due to its transverse engine arrangement, it entails removing an engine mount and it a bit of a job that I am doing a little of every evening after work. I suspect I will be able to get back into the Austin next week. Thank you for the insight. It gives me some more leads to work with. If you have any thoughts as it being somehow related to changing the fuel pump, please let me know. Thank you again.
ANSWER: Hi again!
I think it highly unlikely that your fuel pump replacement affected anything, although it does come off the same ignition-key circuit as the coil. You really need a voltmeter to check that (Radio Shack sells reasonable cheap ones). i) With the ignition off, check the resistance from the pump terminal to ground. It should be essentially infinite. If not, you have a leak somewhere, e.g. an abraded wire touching the frame or similar. ii) With the ignition on and the pump running, check the voltage at the negative coil terminal. You should get the full 12 (actually more like 12.5) volts. But definitely try the HT coil wire test against the block anyway. I'm not good at capacitors, but I think you should get a test spark with it disconnected. If the spark disappears when it's reconnected, the capacitor may have a short. In any case I strongly suspect something inside the distributor, perhaps tied in with the new coil. Perhaps replace your old coil, with a new capacitor?
Sorry not to be more help. Good luck with it!
Jo
---------- FOLLOW-UP ----------
QUESTION: Well, as soon as I finish with the Buick and have the time, probably Monday or Tuesday, I am going to try and check several things. Actually, with your mentioning that the fuel pump comes off of the same ignition circuit it is really starting to sound like something is amiss there, as there was no problem with ignition before this item was changed. (Of course, I automatically suspected that after such a long sleep, some things like the coil might have gone bad and my successful ignition firing up until that time had been its last gasps. The points definitely needed replacing as they showed some signs of burning, but in the long run nothing else might have been bad, although the old distributor cap did not have as positive and action on the brush as the new one) If it is the fuel pump putting out the fire, so to speak, it may require some creative wiring to work around this since it is a negative ground pump on a positive ground car. (Much like it did to wire up a negative ground stereo some years before.) In any case, you have been very helpful and have given me the answers that I suspect will allow me to fix the problem. What made me think of the fuel pump possibly being an issue was, as I mentioned, having heard of a couple of things like that happening before, especially on a positive ground system.
The closest that I came to dealing with something like that myself was talking to friend who had and older Triumph that had somehow grounded out through the horn wiring in the steering column. That proved to be a very difficult problem to track down. I suspected this as a possibility and disconnected the horn during the quest to rule this out.
I read one of your previous posts regarding having the battery wired up backwards and running negative in a positive system, which I found interesting. I had an acquaintance who did something similar with a 1949 Ford truck, (that he did not realize was positive ground). It did not work for him. However, my father, who is a retired mechanic, former aircraft mechanic, and industrial millwright, mentioned that he had seen such things work as well. Sometimes it caused problems and sometimes it did not and they were driven like that indefinitely.
In the case of the guy with the Ford Truck, he eventually got the polarity right, but he had installed a 12 volt battery in a 6 volt system without doing anything else to convert it. I told him that this was definitely going to cause problems. However, he insisted that he only needed to put in 12-volt lights and instrument lights. Needless to say, he was wrong and pretty soon he had fried about every piece of electrical equipment in the truck. The disturbing part of this story is that he got a job as a NASCAR team mechanic about a year later. (Don't know how that worked out or how the team did, as that was about the time I quit following NASCAR to any real degree and I never saw or heard from the guy again.)
Anyhow, thank you again. You have really be quite a bit of help and I think this has pointed me in the right direction enough so that I can get the old Austin back on the streets.
AnswerFinal comment: the negative-ground pump could well be a problem (hard to insulate the body of a pump from the frame). I strongly suggest you reinstall your original pump (assuming that it can still manage to tick) and the original coil. And a new capacitor, which may have been fried by the new coil. Your original problem (fired, but didn't run) was a fuel problem, not a spark one, so return to base... End of transcript! Jo
