Interesting ignition situation
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=30846
Printed Date: October-08-2024 at 9:14pm
Topic: Interesting ignition situation
Posted By: TX Foilhead
Subject: Interesting ignition situation
Date Posted: July-20-2013 at 11:48pm
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OK I got everything back together and running briefly and now I have this issue. I had a module go out so I replaced it and now everything runs very rough for 30sec or so and I begin to loose RPM's and it eventually dies. When I get the multimeter out I have 2 or 3 volts coming out of the ballast resistor (new) and a few more on the other side. So I know what's wrong, just can't seem to figure out where. I've completely opened up the harness an looked at every crimp. I have battery voltage to the plug on the motor, there's some Y where the purple splits to become red (to resistor) green (to - side of the coil) red (to the electric choke). The purple on the resistor starts there and goes to the + side of the coil. I can't figure out what might be causing the voltage to drop, any ideas? Should the resistor be grounded? The plate it sits on is bolted to the block, but it's now painted. I don't see anything that makes me believe it needs a ground looks like all the current stays inside. It starts rough, plugs are new, and seems to get better for a while before it via downhill. The plugs are black now, I think thats from lack of spark and they will clean up once I run it for an hour of so. I will replace the plugs once it's running consistantly. |
Replies:
Posted By: 8122pbrainard
Date Posted: July-21-2013 at 7:32am
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Don, The ballast resistor should not be grounded. It's there to knock down the nominal 12 volts to about 9 going to the coil. You should have the nominal 12 on the one side of the resistor. You need to continue your search to see where you are loosing the volts. Start at the ignition switch and see what is going in and coming out. They can go bad. You can check volts or resistance. You should have close to 0 Ohms between the B and I terminals (disconnect the I wires for the Ohm test). ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: TX Foilhead
Date Posted: July-21-2013 at 12:39pm
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Will check the switch, its brand new and the problem was there before I changed it. Never liked the plastic one that was usually loose. The Ballast resistor is new as well, $10 for the correct one from Mallory with the module. Like the last one it has same volts on each side when I first turn it on, once it warms up there is a difference in the 2 sides. Of course I've never measured one when it is working properly so I don't know if that is correct. The connection where the red green and purple wires split apart seems to give me various readings, i think it is the glue from the shrink wrap, is it possible that got into the crimp and is causing an issue? It looks like a female disconnect with no barrel, the wires are in the circular part on each side. OK I guess its time to get up under the dash and down in the bilge....ugh. |
Posted By: 63 Skier
Date Posted: July-21-2013 at 1:24pm
If the crimp is done well it won't matter if the shrink wrap gums it up a bit, but sounds to me like you question if it's a good connection either way. I'd suggest that you clean up connections that look bad to you, cut it out and connect newly stripped wire ends with proper connectors. I was chasing a power problem on my '98 a couple of weeks ago and found a bad connector. There wasn't much slack so was a bit tough to work on under the dash but I got it connected with a new crimp connector and problem fixed. ------------- '63 American Skier - '98 Sport Nautique |
TX Foilhead wrote:Posted By: TX Foilhead
Date Posted: July-21-2013 at 2:14pm
| The search continues, everything is good to the plug behind the dash. I did leave the ignition on for about 10 min and noticed that the posts heated up to 190, I know it gets warm, but could that be my issue? Coil was cool and the wires on both ends were cool as well. |
Posted By: Bri892001
Date Posted: July-21-2013 at 3:09pm
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You mean the ignition key switch heats up? It shouldn't to that degree. It's not shorting to ground somewhere is it? |
Posted By: 8122pbrainard
Date Posted: July-21-2013 at 3:18pm
Don, Whenever I troubleshoot wiring on the ignition side and know I'll have the ignition switch turned on for any time, I pop the distributor cap and slip a business card between the point set. Keep in mind the point set is the ground to the coil. The only problem with this is you can't diagnose coil and point problems. It works for primary wiring issues only. Without a load on the primary bad connections may not show up so, in that case you close the point set (or shunt with a jumper) and continue on with the VOM. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: TX Foilhead
Date Posted: July-21-2013 at 3:36pm
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It was the ballast resistor that heated up, I wouldn't have noticed it if I didn't see a tiny bit of smoke. I've burnt my finger on it once before so I grabbed the IR thermometer before I touched it and turned the key off when I saw how hot. It certainly wouldn't surprise me if it's a ground issue, the painted motor looks fantastic but it's caused a lot of headaches trying to get things grounded. |
Posted By: TX Foilhead
Date Posted: July-21-2013 at 5:08pm
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OK the problem seems to be somewhere between the reistor and the distributor and the new module is no good. If I block off the sensor in the dizzy I end up with low voltage on the red wire 10.4 and 4.2 on the other side. If I take the distributor out I get battery voltage 12.5 at both ends of the resistor and no heat. I don't have a good explanation at to why, but I do know where and there are no more connections I can fix. Will be ordering a DUI in the morning, should have done that last week so I could be on the water now. Thanks for the help. |
Posted By: Bri892001
Date Posted: July-21-2013 at 7:06pm
| I'm interested to here what the DUI does for you for running/performance. |
Posted By: TX Foilhead
Date Posted: July-21-2013 at 8:15pm
| I would really like to know what difference it makes alone, but I haven't run with the new heads and cam enough. I was thinking I could do that when I got the last module, but apparently I was wrong. I guess all isn't wasted, I learned a lot about why they use things and why it wired that way from the old guys in the hood. Now if I could find someone who could show me that much about fuel injection I would truely be set. |