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Anonymous
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just installed petronix ignition in my 70 250 and i was wondering where should i set my timing at / having trouble starting could the gap on ignition be a problem?
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Anonymous
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Ford sets the stock timing at 6* BTDC. Try setting it to 10*-12* BTDC. Did you remove the ballast resistor? The instructions say to remove it. The ballast resistor is located under the dash in the red line between the switch and the firewall. It will take the form of a small rectangular box (usually white) or a resistor wire in the line. It is easy to spot. If you are running a PII you simply cut it out of the line. If you are reading between 8 - 9 volts at the coil wire, you have either a ballast resistor or a resistor wire.
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Hi phxstangs,
Don is correct. The Pertronix won't operate propertly without 12 volts. Also, you need to gap the module at .030. With the extra kick of the Pertronix if your distributor cap and / or rotor are old / weak they will cause trouble for you. I would recommend a full electrical tune. Cap, rotor, plug wires and plugs. You will like the system once sorted out.
Enjoy the process - Steve
Don is correct. The Pertronix won't operate propertly without 12 volts. Also, you need to gap the module at .030. With the extra kick of the Pertronix if your distributor cap and / or rotor are old / weak they will cause trouble for you. I would recommend a full electrical tune. Cap, rotor, plug wires and plugs. You will like the system once sorted out.
Enjoy the process - Steve
Get a multimeter. my 65 didn't have a ballast resistor. I was getting 12Vs at the coil. YOu can either remove it or find another 12V switched source.
Also, pertronix (according to the website) will operate down to 8-9Vs, and some people report no problems with 6Vs. I'd find a 12V source though if you don't have one.
Also, 6*BTDC is for manual trannies, 10-12*BTDC for automatics.
Slade
Also, pertronix (according to the website) will operate down to 8-9Vs, and some people report no problems with 6Vs. I'd find a 12V source though if you don't have one.
Also, 6*BTDC is for manual trannies, 10-12*BTDC for automatics.
Slade
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so i should only have the two wires from the petronix ignition hooked up to the coil (i have a red wire going into the firewall hook up)
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CobraSix":3ajzi2bz said:
What causes a difference here? What makes the automatic need more advance?
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Generally speaking, the auto tranny loads the engine less at low RPM than does a stick. Also generally speaking, the auto loses lots of power at low RPM, so the extra advance helps pep it up a bit.
There's often a caveat here, though - the distributors associated with auto trannys also have less centrifugal advance by the 4-6 degrees static difference, so the total advance comes out about the same. That's one reason why, when you look inside the dizzy at the weights, you'll see two different slots, typically 11 and 13 degrees (or so, depending on year). This becomes 22 or 26 degrees at the crank. If you add the 12 degree static timing for the auto to the 22 degrees centrifugal, that's 34 total. If you add the 6 degrees static to the 26 degrees centrifugal for the manual, that's 32 total. These are comfortable numbers for a Ford engineer who has to worry about warranty costs and the like, but may not be best for MPG or HP optimizations.
Often, I have seen auto trannys using manifold vacuum for the distributor (pre-emissions) where there was port vacuum for the manuals, but the springing was lighter in the port vacuum diaphragms for quicker advance when port vacuum was available. The auto version often has stiffer vacuum advance springing for less advance action with the stronger manifold vacuum.
A quick-and-easy MPG boost in heavy traffic can come from switching from port vacuum to manifold vacuum. This will require that you turn down the idle speed stop screw, which in turn uses less gas at idle. I do this with my dual-inline-fours all the time, as the traffic seldoms breaches 40 MPH, so the advance stays high. However, when you stomp on it the manifold vacuum can drop away a little faster than port vacuum might (depending on WHERE in the manifold you take the vacuum from), which might make it seem slightly less peppy until the mechanical advance picks up the slack. This is where extra static advance can help.
...in my opinion.
There's often a caveat here, though - the distributors associated with auto trannys also have less centrifugal advance by the 4-6 degrees static difference, so the total advance comes out about the same. That's one reason why, when you look inside the dizzy at the weights, you'll see two different slots, typically 11 and 13 degrees (or so, depending on year). This becomes 22 or 26 degrees at the crank. If you add the 12 degree static timing for the auto to the 22 degrees centrifugal, that's 34 total. If you add the 6 degrees static to the 26 degrees centrifugal for the manual, that's 32 total. These are comfortable numbers for a Ford engineer who has to worry about warranty costs and the like, but may not be best for MPG or HP optimizations.
Often, I have seen auto trannys using manifold vacuum for the distributor (pre-emissions) where there was port vacuum for the manuals, but the springing was lighter in the port vacuum diaphragms for quicker advance when port vacuum was available. The auto version often has stiffer vacuum advance springing for less advance action with the stronger manifold vacuum.
A quick-and-easy MPG boost in heavy traffic can come from switching from port vacuum to manifold vacuum. This will require that you turn down the idle speed stop screw, which in turn uses less gas at idle. I do this with my dual-inline-fours all the time, as the traffic seldoms breaches 40 MPH, so the advance stays high. However, when you stomp on it the manifold vacuum can drop away a little faster than port vacuum might (depending on WHERE in the manifold you take the vacuum from), which might make it seem slightly less peppy until the mechanical advance picks up the slack. This is where extra static advance can help.
...in my opinion.
phx,
the way it should go is the ignition wire from the fire wall should be hooked up the the + side of the coil. The black wire from the pertronix should be hooked up to the - side of the coil.
The red wire from the pertronix is just a power wire. It just needs a switched 12V source. if you are getting 12 V from the ignition wire from the firewall, just hook up the red pertronix to it (either at the coil or spliced into the ignition wire).
If you are only getting like 8-9 Vs at the ignition wire, find another 12 V switched source or remove the ballast resistor. All though, some cars (I think mustangs are one of them, but not all mustangs) used a resistor wire instead of a ballast resistor. Concept is the same. You can also try wiring the red petronix just after the ignition switch under the dash. That will bypass any ballast resistor or resistor wire (the resistor wire voltage drop is based on the length of the wire, so splicing into it at the beginning will give almost no voltage drop to the pertronix).
Clear as mud?
You need a multimeter. Spring the $20 for a decent one at Autozone or the like.
Slade
the way it should go is the ignition wire from the fire wall should be hooked up the the + side of the coil. The black wire from the pertronix should be hooked up to the - side of the coil.
The red wire from the pertronix is just a power wire. It just needs a switched 12V source. if you are getting 12 V from the ignition wire from the firewall, just hook up the red pertronix to it (either at the coil or spliced into the ignition wire).
If you are only getting like 8-9 Vs at the ignition wire, find another 12 V switched source or remove the ballast resistor. All though, some cars (I think mustangs are one of them, but not all mustangs) used a resistor wire instead of a ballast resistor. Concept is the same. You can also try wiring the red petronix just after the ignition switch under the dash. That will bypass any ballast resistor or resistor wire (the resistor wire voltage drop is based on the length of the wire, so splicing into it at the beginning will give almost no voltage drop to the pertronix).
Clear as mud?
You need a multimeter. Spring the $20 for a decent one at Autozone or the like.
Slade
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Anonymous
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which ignition coil do you recomend flamethrower or accel one and what should i gap my plugs two
Honestly, they are probably both made is the same factory in China.
I went with flamethrower because I liked the chrome.
In other words, it doesn't matter. See what teh output coltage is. the flamethrouwer is 45k volts.
With that an Pertronix, I set my plug gap to .042-.045 with good results.
Slade
I went with flamethrower because I liked the chrome.
In other words, it doesn't matter. See what teh output coltage is. the flamethrouwer is 45k volts.
With that an Pertronix, I set my plug gap to .042-.045 with good results.
Slade
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Anonymous
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thxs for all the feedback im going to try to splice into it
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spliced it is getting 12+ volts on pos. side of coil. when i checked the voltage across whole coil (neg lead to neg post, pos lead to neg post reads 6+ volts is this correct)
:phxstangs":3m2g1g8k said:
That is simply measuring the voltage drop across the windings of the coil. It is meaningful only if you have a known good unit to compare it to or if you have a factory specification for this coil. Basic DC theory tells us that 100% of the applied voltage will be "dropped" across a completed circuit, so this tells me that 6 volts are being dropped in the remainder of the circuitry in the Pertronix module. This may be normal for that unit while being tested in static condition. It could change depending on the exact position of the rotor/module relationship. Try rotating the engine slowly by hand while taking the same reading (remove the coil wire for safety). I would expect to see a fluctuation as the engine is rotated, which really just tells us that the unit is working. The real question is "Does it run?"
Joe
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Anonymous
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So is there an actual difference between the maunal and auto dizzy or is it just a weight setting? from the sound of things there is a difference in the way the advance comes in? not just the total amounts.
All of this is pointing to my situation as well, running a DSII distributor and MSD ignition... having trouble with the idle and timing settings?
I am playing right now with the advance vs. timing, and using a ported or full manifold vacume source?
All of this is pointing to my situation as well, running a DSII distributor and MSD ignition... having trouble with the idle and timing settings?
I am playing right now with the advance vs. timing, and using a ported or full manifold vacume source?
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