Just got a 97 ranger 5spd. i read in the owners manal about dual spark and sure enough i look under the hood and see 8 spark plugs. whats this all about??

 

It is called MCE, it is for enhancing the revenues of the aftermarket parts and service providers. MCE==Maintenance Cost Enhancement.

 

THey had an issue with the 4cyl not wanting to start efter they converted it to EFI. They went into the computer and did some work. It turned out to be a timing issue while cranking. The only way they were able to resolve it was to add the second set of spark plugs. When you crank it to start the one set fires either very retarded or advance (I forget which at this point), and once it's running the other set takes over to "run" the engine.

 

They should have just used an old Duraspark ignition. They retard the spark about 20° while cranking. It would seem that the engine computer could have handled a start retard function very easily.

 

Is there any paticular (sp) spark plug i should be using?? What do some of you guys use?

 

I believe I have Motorcraft double platinums in my truck right now. I think that, but I haven't gotten to even 50K miles since they've been in and my stealership friend who sold me the truck did the tuneup before I bought it.

 

That's very untrue. There are lots of EFI single plug engines out there. Any 4 Banger Mustang for example(including turboed units.) Dual plugs promote a more complete burn of the fuel in the combustion chamber with that chamber design, therefore cleaning up emissions, and increasing power output. Don't believe me? Unplug one of the coilpacks, doesn't matter which one, and the engine will still start and run without issue, it's been a looooong time since I fooled around with dad's 96, but, it would run seemingly fine on one set of plugs, but MPG and power would be down by a bit(If I drove it now, even with all 8 plugs, it'd probably still be totally gutless to me... LOL)

 

My single plug injected 2.3 has been starting fine for 20 years. Doan think it is a timing issue, as the ECM can fiddle with the timing all day long w/o needing another set of coils, wires, and plugs.

They are so penny pinching that they will not throw an extra nut or bolt on because one extra can be $millions... Why would they throw two ignition systems on unless they HAD to.
tom

 

I can't speak on this with any authority (not that I'm gonna let that stop me) but what I heard was that dual plug engines located the plugs in different positions in the combustion chamber and used slightly different timing for intake-side plugs vs. exhaust-side plugs to try to ignite the mixture better for a more complete burn, thus reducing emissions.