Yes the bs goes on.
I have an accel coil on my Durango 5.9. I removed it for testing with an Ohm meter for primary and secondary resistance and need to know what the values should be on a properly operating accel coil of this type. I have the haynes manual and the values listed are for the oem coil. Would they be expected to be the same as the accel?
Also the reason why I removed it was because when a calibrated ignition tester was attatched to the coil lead while in the vehicle the coil produced no spark while turning over. I then tested the coil wiring pigtail for voltage while the ignition was on and got only @9volts. This was enough to flash a test probe but is it enough to fire up the coil?

So questions are:

What should the ignition pigtail(or supply) voltage be while cranking?

Does a 9v reading at the pigtail (fully charged battery @13.2V) mean somethings wrong with the voltage supply?

What might cause such a low voltage supply if that is indeed a problem? Relays, stupid computers etc?

What are the primary and secondary resistance ideals for the accel coil? (this is the small yellow coil that directly replaces the oem coil way up front on the 5.9l Magnum)

And finally, does anyone know the web address of accel (or phone number) so I can bug their asses just in case?

Thanks,

I'm screwed big time untill I can get this rig started.


Lee

 

Accel is actually part of MrGasket products. You can find tech support info here: http://go.mrgasket.com/AskTechHome.aspx?BrandID=3

 

I would ask the techs.

 

Thanks for the link guys.
I have sent off an email and hope for a response soon. I'll likely have the coil replaced before I hear from them though. I'll go for an OEM for now as no accel coils are in stock in my city right now. From looking at the specs the OEM coil on these Magnums seems to be right in line with the accel anyway. The accel is just yellow. I could be wrong, but in any event if it is the coil that is preventing me from starting the OEM should allow me to get going for now anyway.

I found the resistance specs for the accel coil here
http://store.summitracing.com/defaul...5&autoview=sku

and mine checks out with a primary within range but a secondary of only 7400 Ohm (should be 12700 ohm). Looks like a bad coil to me but for $40 I can't sit around and wonder.

I'll keep you posted.

Lee

 

Well got her back on the road anyway. Needed a new coil and OEM seems to work ok.
Still has the misfire on Cyl 5 though so as soon as I get a chance I'll do a compression test and calibrated spark test on all cylinders. For now I'm glad I just have her running.
There has been a sound coming from the drivers side "header" that goes away once warm. My fear is that the previous owner over torqued a plug into cyl5 at one time and that is where the sound is coming from. Sound plausable? Plug 5 has a bit of a funny feeling to it as it's being torqued down, and I imagine the sound produced by a leak there would be similar to a header leak and go away as she warmed up and the head expanded. A compression test should tell me a lot more.

 

Forgot to ask.....is there anything that can be done easily without a tear down to help seal the threads of a leaking plug? They aren't stripped by any means but just feel a little funny when torquing down .....like if you torqued even the slightest further it would just spin out.
Just a "feeling" thing. Doesn't feel the same as the others.
anything like a sealant etc?

 

How about some teflon tape around the threads? Not sure if that would help or not, but it's worth a shot.

 

I was thinking loctite.

 

Over the past ten years I have read many many posts about Accel coils that failed in service. The stock coil on my 1995 has lasted over 12 years and 190,000 miles. I haven't read of many MSD coil failures.

Here's an old post that may be of use:
===
Here's what the Accel catalog says about their Magnum Truck coil:

begin quote:

"DODGE "MAGNUM"
TRUCK / JEEP 1997-90 SUPER COIL

Engineered with optimized low resistance, high turns ratio windings around an
M36 high silicone magnetic steel C-core for higher energy and voltage outputs.
Results in quicker starts, improved idle quality, crisper throttle response
and more high RPM power. Compatible with late model MOPAR J-TEC computer
controlled ignition system and MOPAR high performance ignition computers.
Direct bolt-in, plug-in replacement. Can also work with an ACCEL, Mallory,
Crane, Holley or MSD capacitive discharge ignition systems. Special high
temperature epoxy resists shock and vibration, while increasing thermal
conductivity. Brass coil wire contact increases energy transfer efficiency and
resists corrosion better than aluminum. High dielectric strength "ACCEL
Yellow" over molded housing.

SPECIFICATIONS
Primary Resistance 1.0 Ohms
Secondary Resistance 12.7 k Ohms
Turns Ratio 76 : 1
Maximum Voltage 42,000 volts
Peak Increase in Energy vs. OE 34%
Peak Increase in Current vs. OE 17%
Peak Increase in Arc Duration vs. OE 23%
Peak Increase in Dwell vs. OE 36%

Dodge "Magnum" Truck / Jeep 1997-90 Super Coil . .140021"

end quote
-----------------

For Info,
Here is what I measured on my 1995 model year stock Ram ignition coil this
afternoon:

Number on side of coil: 56027966

Primary Resistance 0.99 ohms
Primary Inductance 6.25 milliHenrys
Secondary Resistance 12,250 ohms
Secondary Inductance 41.9 Henrys

I put 6.3 volts of 60 cycle AC on the primary of the stock coil and got 453
volts AC on the secondary. The turns ratio of the stock coil might be about
453/6.3 = 72

A lower turns ratio can be good in that it prolongs the 'burn time' of the
spark
especially at high rpms.

A higher turns ratio can provide a higher voltage to get the spark to jump
but most of the time a higher voltage is not needed. Exceptions are
when the plug is fouled with oil or gasoline, the tip edges have become dull,
or when the tips are cold when the engine is first started.

Above measured with a seventeen year old BK Precision LCR Meter model number
875A and a Fluke 87.

The 1995 FSManual says the coils are made either by Diamond or ToyoDenso.

For the Diamond the primary resistance is supposed to be between .97 and 1.18
ohms and the secondary 11,300 to 15,300 ohms.

For the Toyodenso the pri resis is supposed to be between 0.95 and 1.20 ohms
and the sec 11,300 to 13,300 ohms.
===================

measurements on MSD exact Magnum Engine replacement coil

primary 1.2 ohms
secondary 13,700 ohms
-------------------------
Here's what MSD says about the Blaster SS:

begin quote

Blaster SS Coil, PN 8207
The MSD line of Blaster Coils is known for great performance from the street
to the circle tracks. Following in that performance line, the new Blaster SS
Coil is ready to leave its mark.
The Blaster SS is an E-core style coil, which is a very efficient design when
it comes to producing high voltage and spark energy. The windings produce
300mA and can handle up to 48,000 volts when used with an MSD 6 Series
Ignition Control. The windings are held secure in a DupontĀ® RyniteT injection
molded shell and are then encased in an epoxy compound for protection against
vibration and water. The primary terminals are located at opposite ends of the
tall spark tower so there is no chance of arcing especially with the high
dielectric characteristics of the Rynite housing.
The Coil is compact enough to fit in tight areas and is supplied with
vibrations mounts.
------------------------
Blaster SS Coil - PN 8207 CARB Approval Pending

BLASTER SS COIL SPECIFICATIONS
Primary Resistance: .355 ohms
Peak Current: 300mA
Secondary Resistance: 6,200 ohms
Spark Duration: 180uS
Maximum Voltage: 48,000 volts
Primary Inductance: 6milliHenrys
Turns Ratio: 70:1 Tested with an MSD 6AL
measured at plug gap.
==================

Bowling Ignition Circuit Simulator
Stock Ram Ign Coil part number 56027966

Input Parameters Are the Following:
Starting RPM = 500
Ending RPM = 5000
RPM Step = 250
Ignition Coil Primary Resistance (Ohms)= 1.0
Ignition Coil Primary Inductance (Millihenries) = 6.2
Dwell Angle (Crankshaft Degrees)= 30.0
Battery Voltage = 12.0
Ignition Coil Secondary Capacitance (Picofarads) = 100.0
Computation Results:
Engine Charge Time Primary Current Secondary Voltage Energy
RPM (millisec) (Amps) (Volts) (Joules)
---------------------------------------------------------------
500 10.0000 9.58 75714.7 0.287
750 6.6667 7.87 62219.0 0.194
1000 5.0000 6.61 52241.2 0.136
1250 4.0000 5.67 44845.0 0.101
1500 3.3333 4.96 39214.2 0.077
1750 2.8571 4.40 34808.1 0.061
2000 2.5000 3.96 31276.2 0.049
2250 2.2222 3.59 28386.1 0.040
2500 2.0000 3.29 25979.8 0.034
2750 1.8182 3.03 23946.3 0.029
3000 1.6667 2.81 22206.0 0.025
3250 1.5385 2.62 20700.1 0.021
3500 1.4286 2.45 19384.5 0.019
3750 1.3333 2.31 18225.5 0.017
4000 1.2500 2.18 17196.7 0.015
4250 1.1765 2.06 16277.5 0.013
4500 1.1111 1.95 15451.4 0.012
4750 1.0526 1.86 14704.8 0.011
5000 1.0000 1.77 14026.9 0.010
********************************************

CraneCams LX91 Ign Coil


Stock Ram Coil Part number 56027966.................Crane LX91
Pri Resistance 0.99 ohms....................................0.41ohms
Pri Imped 6.25 mh...............................................5 .3mh
Sec Resis 12,010 ohms......................................3,170 ohms
Sec imp 41.9 Henrys...........................................1 7.1 Henrys

Simulation using Bowlings program:
Input Parameters Are the Following:
Starting RPM = 500
Ending RPM = 5000
RPM Step = 250
Ignition Coil Primary Resistance (Ohms)= 0.4
Ignition Coil Primary Inductance (Millihenries) = 5.3
Dwell Angle (Crankshaft Degrees)= 30.0
Battery Voltage = 12.0
Ignition Coil Secondary Capacitance (Picofarads) = 100.0
Computation Results:
Engine Charge Time Primary Current Secondary Voltage Energy
RPM (millisec) (Amps) (Volts) (Joules)
---------------------------------------------------------------
500 10.0000 15.64 113833.3 0.648
750 6.6667 11.73 85363.4 0.364
1000 5.0000 9.35 68047.3 0.232
1250 4.0000 7.76 56505.2 0.160
1500 3.3333 6.63 48286.3 0.117
1750 2.8571 5.79 42144.1 0.089
2000 2.5000 5.13 37383.0 0.070
2250 2.2222 4.61 33585.5 0.056
2500 2.0000 4.19 30486.8 0.046
2750 1.8182 3.83 27910.6 0.039
3000 1.6667 3.54 25735.2 0.033
3250 1.5385 3.28 23874.0 0.028
3500 1.4286 3.06 22263.6 0.025
3750 1.3333 2.86 20856.4 0.022
4000 1.2500 2.69 19616.5 0.019
4250 1.1765 2.54 18515.6 0.017
4500 1.1111 2.41 17531.6 0.015
4750 1.0526 2.29 16646.8 0.014
5000 1.0000 2.18 15847.1 0.013