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| Coil questions https://slantsix.org/forum/viewtopic.php?t=39392 |
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| Author: | 70valiant [ Sat Mar 13, 2010 5:29 am ] |
| Post subject: | Coil questions |
My Volare has a situation where is seems to have a miss that worsens as the car warms up. I have increased the idle speed in an attempt to keep it running when I come to a stop, but it still stalls on occasion. I am starting to believe the coil (probably original) is on its way out. I would like to test it but I have no clue what the resistance numbers should be, could I get a little help with that? I have about 8 coils laying around (I have no clue where they all came from) and am hoping at least one of them is good. |
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| Author: | terrylittlejohn [ Sat Mar 13, 2010 5:41 am ] |
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if the car hasn`t had a tuned -up in a while it might need it , but first start with a compression check to see if a cylinder is low and if you have adjustable rockers set them 0.010 intake and 0.020 exhaust to get a good reading. |
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| Author: | Dart270 [ Sat Mar 13, 2010 5:47 am ] |
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I second Terry's motions, then try another coil. Tightening valves give exactly the behavior you describe. Lou |
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| Author: | 70valiant [ Sat Mar 13, 2010 7:54 am ] |
| Post subject: | |
I did the valves when I first got it runnning, they were all very loose. A compression check was already on my "to do list" for today. I still want to test the coil, what numbers should I be looking for? This problem started suddenly, up untill two weeks ago (when we finally started getting above freezing) it was fine. |
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| Author: | SlantSixDan [ Sat Mar 13, 2010 8:59 am ] |
| Post subject: | |
With the car cold, start the engine and play a hot hairdryer on suspected components (coil, ignition control box...). If you heat up a component and cause the miss, you've found the faulty part. What has you thinking the coil is faulty, in particular? |
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| Author: | 70valiant [ Sat Mar 13, 2010 3:15 pm ] |
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It has a new cap, rotor, plugs, wires, I rebuilt the carb. It ran great for a month then all of the sudden it has a miss that comes and goes but only after it has warmed a bit. Pocess of elimination says check for a weak coil. |
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| Author: | SlantSixDan [ Sat Mar 13, 2010 3:23 pm ] |
| Post subject: | |
Quote: It has a new cap, rotor, plugs, wires, I rebuilt the carb. It ran great for a month then all of the sudden it has a miss that comes and goes but only after it has warmed a bit. Pocess of elimination says check for a weak coil.
By all means check the coil, but keep an open mind. Still running points, or is this an electronic setup? |
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| Author: | 70valiant [ Sat Mar 13, 2010 4:27 pm ] |
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It's electronic. It's in my 77 Volare. I have to get a pic of it in my sig line. I haven't gotten the compression check done yet, I got called into work. I'm not aboslutly positive its the coil but I need to know what numbers to look for when I get to test it. How many ohms should I get going from the + to the - and from the + to the center? |
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| Author: | SlantSixDan [ Sat Mar 13, 2010 5:42 pm ] |
| Post subject: | |
Quote: It's electronic.
Then I'd suspect the ignition module before I'd suspect the coil. Heat it with a hairdryer with the engine running and see if you can induce the miss. Also don't forget the pickup coil inside the distributor could be faulty when hot.Quote: How many ohms should I get going from the + to the - and from the + to the center?
My FSMs are still boxed up from the office move!
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| Author: | 70valiant [ Sat Mar 13, 2010 5:43 pm ] |
| Post subject: | |
Ok, I found the numbers I was looking for in my haynes manual. The coil checked out good. I pulled the plugs and did a compression test. 1. 145psi 2. 150psi 3. 150psi 4. 155psi 5. 160psi 6. 150psi looks good to me. I was expecting them to be more like 120psi but I'll take it I did find a plug gapped to over .050. I gapped them all to .040. It seems to idle a little better. I richend the idle mixture a little more and I guess I'll have to settle for an idle speed of 850rpm. |
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| Author: | SlantSixDan [ Sat Mar 13, 2010 5:53 pm ] |
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850 is a little high. What type of carb are you running, and what cam? (And what spark plugs)? |
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| Author: | 70valiant [ Sat Mar 13, 2010 6:56 pm ] |
| Post subject: | |
it is a BBD and as far as I know it is a stock cam. The plugs are autolites. I used to be able to get the Valiant to idle as low as 450rpm when I was adjusting rockers and it was smooth as silk at 700rpm |
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| Author: | SlantSixDan [ Sat Mar 13, 2010 9:29 pm ] |
| Post subject: | |
If you can't get a good idle below 850 rpm, something's definitely the matter. Vacuum leak or carburetor flaw, most likely. Autolite plugs are now rather poorly made in China -- go for the NGKs next time. |
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| Author: | walpolla [ Sat Mar 13, 2010 11:53 pm ] |
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Quote: Autolite plugs are now rather poorly made in China -- go for the NGKs next time.
hello,Dan,if you recall,I sent this series of pix to you via email a while back. this will give y'all an insight into WHY those Oriental spark plugs (and other stuff) is suspect in quality. click here ( open the link to the Powerpoint pix once the forum opens.) regards,Rod 
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| Author: | 63Valiant [ Sun Mar 14, 2010 6:19 am ] |
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LOL, you should warn people when you post a link to the demon underground, my computer almost crashed when the collective vacuum of empty minds there screaming in ignorant agony assaulted the processing ability of said computer. 
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