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Is the 4.0 SOHC a wasted spark ignition system?

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Explorer75

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Can someone confirm or deny that the 2006-2010 4.0 SOHC has wasted spark ignition or not?

I thought this ignition with coil and 6 individual connectors wasn´t a wasted spark. Several threads point out that it is...
 



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Yes, it is a waste spark system and is why they came with two different types of platinum plugs from the factory until they switched to the nickel plugs (2008 I think).
 






Don´t mean to be rude but that doesn´t prove it´s a wasted spark ignition.
My explorer came with one kind of platinums from factory, as discussed in other threads factory replacement are nickle plugs. On the contrary, if you look at the plugs then you could assume it´s not a wasted spark. Why go from a platinum plug that lasts a long time to nickel plugs that lasts about one third of the platinums?
 






The nickle in the plug refers to the composition of the long ground tube, not the firing tip of the plug. The nickle is harder material and is not as prone to hanging on to the carbon that tries to build up between the head and the plug. The firing tips (Motorcraft SP514, for the 4.6) are still platinum.

As for 'wasted spark', I do not know. I do not the think the COP's of the 4.6 are wasted spark.

OOPS! I see this thread is for the 4.0 V6. Don't pretend to know anything about them.
 






Explorer75 said:
Can someone confirm or deny that the 2006-2010 4.0 SOHC has wasted spark ignition or not?

I thought this ignition with coil and 6 individual connectors wasn´t a wasted spark. Several threads point out that it is...
Click to expand...

The 2007 Service manual describes the 4.0 liter V6 engine as a wasted spark design because it fires 2 plugs at the same time: 1 & 5, 2 & 6, 3 & 4. The coil is a separate unit and connects to the spark plugs through conventional wires. The V8 uses Coil on Plug ignition (COP).

Good luck.
 






Both the OHV and SOHC motors are wasted spark systems.
 












If you look at the coil pack you will see 4wires on the primary side... 1 12 volt positive (common to all three coils in the "pack") and 3 negative wires. These 3 carry the "signal" from the computer (on OBDII engines, EECIV trucks used a separate ICM.) to the coil. The only way to send spark down 6 plug wires with only 3 inputs is to fire 2 at the same time.
The beauty of this style system is that it doesn't need to know whether its firing #1 or #5 ... It just fires both. That eliminates the need for a cam sensor for the ign system to work. But, I may just be rambling on after you already got your answer.
 






snoranger said:
If you look at the coil pack you will see 4wires on the primary side... 1 12 volt positive (common to all three coils in the "pack") and 3 negative wires. These 3 carry the "signal" from the computer (on OBDII engines, EECIV trucks used a separate ICM.) to the coil. The only way to send spark down 6 plug wires with only 3 inputs is to fire 2 at the same time.
The beauty of this style system is that it doesn't need to know whether its firing #1 or #5 ... It just fires both. That eliminates the need for a cam sensor for the ign system to work. But, I may just be rambling on after you already got your answer.
Click to expand...

No rambling, thanks for the details :thumbsup:
 






snoranger said:
... It just fires both.
Click to expand...

And is why I stated that the way the two types of plugs were designed proves that it is a waste spark system since when both plugs fire they fire in opposite polarity. A well written article on the waste spark DIS can be read here: http://www.motor.com/article.asp?article_ID=195 BTW this article talks about using oscilloscopes to troubleshoot these systems, but you cannot find many shops at all anymore (or technicians for that matter) that have a scope or know how to use one.
 






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