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Re: Electrical Gurus Needed - UPDATE
[Re: cjskotni]
#1326030
11/12/12 01:39 PM
11/12/12 01:39 PM
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Joined: Oct 2007
Posts: 3,903
Oregon
hooziewhatsit
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Oregon
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Unplug the coil wire at the distributor, and wedge it somewhere that holds it 1/4" from a ground point. Crank the engine and see what the spark look likes. Do this again after it dies and make sure the spark looks the same. I wouldn't necessarily trust just a timing light on the coil wire as an indicator of good spark. You can also disconnect the two pin plug from the ECU to the distributor, then tap the male terminal on the ECU side to ground (morse-code style), and you should get a shower of sparks from the coil wire. Have you check the reluctor gap recently? I had a new disty I gapped, then over the next week I went from good start to hard start to no start. The gap had opened itself up to ~0.040"+  
If you ever find yourself in a fair fight, your tactics suck.
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Re: Electrical Gurus Needed - UPDATE
[Re: hooziewhatsit]
#1326031
11/12/12 02:13 PM
11/12/12 02:13 PM
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Joined: Jul 2007
Posts: 1,526
North Carolina
cjskotni
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Quote:
Unplug the coil wire at the distributor, and wedge it somewhere that holds it 1/4" from a ground point. Crank the engine and see what the spark look likes.
Do this again after it dies and make sure the spark looks the same. I wouldn't necessarily trust just a timing light on the coil wire as an indicator of good spark.
You can also disconnect the two pin plug from the ECU to the distributor, then tap the male terminal on the ECU side to ground (morse-code style), and you should get a shower of sparks from the coil wire.
Have you check the reluctor gap recently? I had a new disty I gapped, then over the next week I went from good start to hard start to no start. The gap had opened itself up to ~0.040"+
When you tap the 2 pin pickup connector to ground, should this be without the coil to distributor wire disconnected? I am guessing you are trying to simulate the pickup signal and "trick" the ECU into firing the coil...
I will also check the reluctor gap as you suggested.
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Re: Electrical Gurus Needed - UPDATE
[Re: cjskotni]
#1326032
11/12/12 04:03 PM
11/12/12 04:03 PM
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Joined: Jul 2007
Posts: 1,526
North Carolina
cjskotni
OP
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I went ahead, took some old parts back, and bit the bullet and purchased a brand new MSD Blaster II coil....the exact same model I had. Fired the car up and died after about 15 minutes again BUT I could restart it with some degree of effort. Once restarted, I hooked up a spark tester to the #7 wire and this is what I see: - 10K volts: consistant spark - 20K volts: seems to lose maybe 20% of the sparks? - 30K volts: maybe get 20% of the sparks losing 80+% very inconsistant This is a advertised 45K volt coil. I would think I should be getting more energy than that at the plug. I guess I will have to repeat with a cold motor. BTW when I crank it with the tester on, you can definitley see a MUCH brighter spark as would be expected. If I am getting a large secondary voltage drop between coil and plugs, I guess I am down to dizzy and wires now...would ECU weaken spark? I have a new one of those I can swap back -- maybe I can try later... At least maybe some change in the right direction... 
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Re: Electrical Gurus Needed - UPDATE
[Re: cjskotni]
#1326033
11/12/12 04:30 PM
11/12/12 04:30 PM
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Joined: Dec 2010
Posts: 208
Norrland, Sweden
Swedcharger67
enthusiast
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enthusiast
Joined: Dec 2010
Posts: 208
Norrland, Sweden
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I think it goes back to the previous step, if you don't have all "juice" in on the primary winding in the coil...you don't get all juice out from the secondary winding to the spark plugs.
I would still look for the reason why you have that low 11.something volts in to ballast resistor and corresponding low voltage (= low current = low energy = weak spark) to the coil.
Martin, 67 Charger, 512 cui, E85, MegaSquirt MS3X sequential ignition & injection
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Re: Electrical Gurus Needed - UPDATE
[Re: Swedcharger67]
#1326035
11/12/12 05:36 PM
11/12/12 05:36 PM
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Joined: Jul 2007
Posts: 1,526
North Carolina
cjskotni
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Quote:
I think it goes back to the previous step, if you don't have all "juice" in on the primary winding in the coil...you don't get all juice out from the secondary winding to the spark plugs.
I would still look for the reason why you have that low 11.something volts in to ballast resistor and corresponding low voltage (= low current = low energy = weak spark) to the coil.
The 11.something reading was with the engine OFF. With the motor running, the reading on the blue wire of the ballast is 14+V.
Quote:
Don't think you use a ballast resisitor with a MSD coil. Check the instrutions.
I will read the instructions but I have run this exact coil for a LONG time with ballast and no issues like this. Maybe I could ditch it but I don't think it is necessary to run without one. If this had been the case from day one, I'd agree with you but this problem began with a perfectly running car. I even had it dynoed with this exact same setup before this began...
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Re: Electrical Gurus Needed - UPDATE
[Re: Swedcharger67]
#1326038
11/12/12 07:12 PM
11/12/12 07:12 PM
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Joined: Jul 2007
Posts: 1,526
North Carolina
cjskotni
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Quote:
Quote:
The 11.something reading was with the engine OFF. With the motor running, the reading on the blue wire of the ballast is 14+V.
A normal, fully charged battery should hold 12.8 volts.
Your ignition system will draw 3.6 amps (only!) and your voltage feed to the ballast & coil drops to 11.something...there is something that doesn't add up...
Voltage at battery is ~12.7V (not fully charged from cranking), voltage @ black pin on ign switch harness is ~12.25V, voltage at blue pin of ign switch harness is ~12.05V.
Looks like I am losing about .4 volt on each bulkhead connections (and wire run) and about 1/4 volt on the ignition switch itself. This would account for the difference. However running it's 14+V @ the ballast so I think that's OK.
I agree it seems high but those connections are CLEAN and packed with dialectric grease. I dn't see it getting much better...
Can anybody here tell me what a "healthy" spark voltage to have is at the plugs? The consistant 10KV I am getting seems low. Would this be low enough to cause my engine dying problem?
I would think even with OEM coil, I would be getting a solid 15-20KV at least...
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Re: Electrical Gurus Needed - UPDATE
[Re: cjskotni]
#1326039
11/13/12 01:19 AM
11/13/12 01:19 AM
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Joined: Jan 2003
Posts: 5,445
So Cal
Sinitro
master
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master
Joined: Jan 2003
Posts: 5,445
So Cal
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Quote:
Quote:
Quote:
The 11.something reading was with the engine OFF. With the motor running, the reading on the blue wire of the ballast is 14+V.
A normal, fully charged battery should hold 12.8 volts.
Your ignition system will draw 3.6 amps (only!) and your voltage feed to the ballast & coil drops to 11.something...there is something that doesn't add up...
Voltage at battery is ~12.7V (not fully charged from cranking), voltage @ black pin on ign switch harness is ~12.25V, voltage at blue pin of ign switch harness is ~12.05V.
Looks like I am losing about .4 volt on each bulkhead connections (and wire run) and about 1/4 volt on the ignition switch itself. This would account for the difference. However running it's 14+V @ the ballast so I think that's OK.
I agree it seems high but those connections are CLEAN and packed with dialectric grease. I dn't see it getting much better...
Having the bulkhead connections, kleen and packed with dia-lectric grease are (2) of the 3 requirements...
The other one is being tite..
The female tab 0.25" tab connector on the firewall side must grip the male side titely... 
After 45 years these connections can be marginal and it doesn't take much to lose the required voltage. What I normally do is to insert a small pair of needle nose pliers and crimp down slightly on the female side...
Just my $0.02... 
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Re: Electrical Gurus Needed - UPDATE
[Re: hooziewhatsit]
#1326042
11/13/12 10:44 AM
11/13/12 10:44 AM
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Joined: Jul 2007
Posts: 1,526
North Carolina
cjskotni
OP
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North Carolina
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Quote:
Quote:
When you tap the 2 pin pickup connector to ground, should this be without the coil to distributor wire disconnected? I am guessing you are trying to simulate the pickup signal and "trick" the ECU into firing the coil...
I will also check the reluctor gap as you suggested.
During this test you'll still have the coil wire off the distributor and 1/4" from a ground point. And yes, this tricks the ECU into firing the coil.
In my case, I had weak/no spark while cranking (gap too large), but had an avalanche of HUGE sparks when I tapped the plug to ground.
If it dies and you have good spark with this test, then it shows the ECU side is ok, and narrows the problem to the pickup side.
You might also jump battery voltage around the bulkhead/ignition switch to make sure you have good voltage to the ECU/BR.
I will try this test next time I have a block of time to crank her up again. Thanks for the information! Another thing I might try aftre the motor dies is jump (for a limited time) from the + terminal on battery to the + terminal on the coil to give it full voltage. Would this harm the coil if I had this on for a few minutes? I just don't want to cook my coil. :-(
I would assume if this worked, it points to weak spark which would indicate and ECU/wiring/coil issue. Sicne I am getting a consitant spark at the plug (after motor dies), I am guessing puckup is OK. The pickup indirectly controls when and IF the coil fires but not the magnitude of the spark itself or am I wrong?
It just seems odd I am only getting a consistant spark at 10kV or less. When I widen the tester gap to 20kV or higher the spark becomes very inconsistant. My memory could be failing me here but I seem to remember this motor (and other stock engines of various makes) having no trouble arching across the tester at 20-30kV.
Quote:
I don't think there's anything wrong with your wireing,it is the pickup coil in the dizzy. Pull the dist out and put in another one............problem solved.
I would agree with you but I installed a brand new pickup last month. No change.
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Re: Electrical Gurus Needed - UPDATE
[Re: Swedcharger67]
#1326046
11/13/12 11:02 PM
11/13/12 11:02 PM
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Joined: Jul 2007
Posts: 1,526
North Carolina
cjskotni
OP
pro stock
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OP
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Joined: Jul 2007
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North Carolina
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Thanks for all the ideas guys, I appreciate the suggestions so far. I managed to get out in the garage again today and with the new coil in, I got it to run for about 45 minutes straight while I tested various voltages, etc. It seems the motor is fine (doesn't drop idle speed) if the voltage on the high side of the coil stays above ~4V. I noticed that with the fans on @ in-gear idle, the voltage on the coil starts dropping to 3.8-3.9V which makes the engine idle lower (weaker) which spins the alternator less which lowers the voltage and so on until it dies. I went ahead and fiddled with the engine harness bulkhead connector and the ignition switch harness to dash harness connection and managed to get an extra .2V or so on the ignition side of the ballast which gave a lil more "oomph" to the coil. With that little bit extra the engine stayed running MUCH longer and didn't die on me. I measured all the volatges and I am seeing a net loss of only .8V from + battery terminal to ballast now. I am guessing the issue may be the Blaster II coil I have "wants" more voltage (and current) than the stock coil would. My ballast resistor is sitting at near 2 ohms across it which is dropping the voltage from 14+ to 4 volts on coil or so which is marginal from what I see. I ordered an Accel ballast which is supposed to .65 ohms and a Mopar ballast which is supposed to be 1.4 ohms. I am going to try both of these to see if I can't get some more voltage and current on that coil. BTW, the ballast they recommend for this coil (and, yes it SHOULD have one) is .85 ohms. I am hoping by getting rid of some of the voltage drop on the ballast I can better "feed" this coil even if the alternator drops to 700 RPM in gear and falls behind. I also found that the brown pin on the brand new M&H dash harness I have was pushed back out of the Molex connector probably causing a weak connector on the start circuit. I fixed this and packed that connector with dielectric grease as well. This helped with some of the voltage drop I was seeing. Hopefully I will get the new ballasts in by this weekend and I can fill everyone in on if this helps my issue. Does anybody else here run a Blaster II coil with the MP Elec Ign? If so, can you tell me what your MSD coil "likes" as far as voltage goes and/or what ballast you run? Quote:
During this test you'll still have the coil wire off the distributor and 1/4" from a ground point. And yes, this tricks the ECU into firing the coil.
In my case, I had weak/no spark while cranking (gap too large), but had an avalanche of HUGE sparks when I tapped the plug to ground.
If it dies and you have good spark with this test, then it shows the ECU side is ok, and narrows the problem to the pickup side.
You might also jump battery voltage around the bulkhead/ignition switch to make sure you have good voltage to the ECU/BR.
I did this test with engine hot and cold. Both times getting good spark! I used a spark plug tester to connect the coil wire to ground and a remote starter to jump the pickup connector to ground. Worked like a charm and I could see the strength of the spark! With the engine not running, I was getting 20-25 kV of juice! So I guess this means coil and ECU are good?
Thanks again to all you guys for you help and suggestions!! 
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Re: Electrical Gurus Needed - UPDATE
[Re: cjskotni]
#1326047
11/13/12 11:33 PM
11/13/12 11:33 PM
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Joined: Jan 2003
Posts: 5,445
So Cal
Sinitro
master
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master
Joined: Jan 2003
Posts: 5,445
So Cal
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Quote:
Thanks for all the ideas guys, I appreciate the suggestions so far.
I managed to get out in the garage again today and with the new coil in, I got it to run for about 45 minutes straight while I tested various voltages, etc.
It seems the motor is fine (doesn't drop idle speed) if the voltage on the high side of the coil stays above ~4V. I noticed that with the fans on @ in-gear idle, the voltage on the coil starts dropping to 3.8-3.9V which makes the engine idle lower (weaker) which spins the alternator less which lowers the voltage and so on until it dies.
I went ahead and fiddled with the engine harness bulkhead connector and the ignition switch harness to dash harness connection and managed to get an extra .2V or so on the ignition side of the ballast which gave a lil more "oomph" to the coil. With that little bit extra the engine stayed running MUCH longer and didn't die on me. I measured all the volatges and I am seeing a net loss of only .8V from + battery terminal to ballast now.
I am guessing the issue may be the Blaster II coil I have "wants" more voltage (and current) than the stock coil would. My ballast resistor is sitting at near 2 ohms across it which is dropping the voltage from 14+ to 4 volts on coil or so which is marginal from what I see. I ordered an Accel ballast which is supposed to .65 ohms and a Mopar ballast which is supposed to be 1.4 ohms. I am going to try both of these to see if I can't get some more voltage and current on that coil. BTW, the ballast they recommend for this coil (and, yes it SHOULD have one) is .85 ohms. I am hoping by getting rid of some of the voltage drop on the ballast I can better "feed" this coil even if the alternator drops to 700 RPM in gear and falls behind.
I also found that the brown pin on the brand new M&H dash harness I have was pushed back out of the Molex connector probably causing a weak connector on the start circuit. I fixed this and packed that connector with dielectric grease as well. This helped with some of the voltage drop I was seeing.
Hopefully I will get the new ballasts in by this weekend and I can fill everyone in on if this helps my issue.
Does anybody else here run a Blaster II coil with the MP Elec Ign? If so, can you tell me what your MSD coil "likes" as far as voltage goes and/or what ballast you run?
Quote:
During this test you'll still have the coil wire off the distributor and 1/4" from a ground point. And yes, this tricks the ECU into firing the coil.
In my case, I had weak/no spark while cranking (gap too large), but had an avalanche of HUGE sparks when I tapped the plug to ground.
If it dies and you have good spark with this test, then it shows the ECU side is ok, and narrows the problem to the pickup side.
You might also jump battery voltage around the bulkhead/ignition switch to make sure you have good voltage to the ECU/BR.
I did this test with engine hot and cold. Both times getting good spark! I used a spark plug tester to connect the coil wire to ground and a remote starter to jump the pickup connector to ground. Worked like a charm and I could see the strength of the spark! With the engine not running, I was getting 20-25 kV of juice! So I guess this means coil and ECU are good?
Thanks again to all you guys for you help and suggestions!!
According to the Mopar Performance catalog..
When using a Blaster coil, the correct ballast resistor value is 0.25 Ohms which is Mopar #P2444641. A higher value ballast resistor will greatly decrease the primary voltage to the coil and its respective HV output...
Just my $0.02..
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