Another Ranger Question?

[Gremlin]

What does having two spark plugs per cylinder do? do they fire at the same time, one a few degrees after the other,or alternately . Also how often do you change plugs.

I know these questions have been asked before and are somewere in previous threads, but i don't know how to find them?


Thank You

 

[blacksnapon]

Ignition System

Item Part Number Description
1 12029 Ignition Coil
2 12259 Spark Plug Wire Set
3 12405 Spark Plug

During basic operation, the powertrain control module (PCM) (12A650)determines the ignition timing required by the engine (6007) and determines which ignition coil (12029) to use.

The camshaft position (CMP) sensor (6B288) is used only for fuel charging. This sensor allows the sequential fuel injection (SFI) system to inject fuel in cylinder firing order; refer to Section 303-04A.

Refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual for further information on ignition system components and their functions. Refer to the Wiring Diagrams for ignition system wiring diagrams.

Ignition Coils

Two ignition coil packs are used for the 2.5 twin-plug engine. The two ignition coil packs are triggered and timed by the powertrain control module. Each coil pack contains two separate ignition coils for a total of four ignition coils. Each ignition coil fires two spark plugs (12405) simultaneously, one spark plug on the compression stroke and one on the exhaust stroke. The spark plug fired on the exhaust stroke uses very little of the ignition coil's stored energy. The majority of the energy is used by the spark plug on the compression stroke. Since these two spark plugs are connected in series, the firing voltage of one spark plug will be negative with respect to ground, while the other will be positive with respect to ground. Refer to the Powertrain Control/Emissions Diagnosis (PC/ED) manual for additional information on spark plug polarity.

Spark Plugs

For production and service in 1998, all eight spark plugs are AWSTF32-F.

Dual Plug Inhibit

Dual Plug Inhibit (DPI) is a function of the powertrain control module that is used when the vehicle is being started. During engine cranking, the powertrain control module will only fire the spark plugs on the right-hand side of the engine. When the engine has started, the powertrain control module will start normal twin-plug operation.

 

[Gremlin]

This is to deep for me, I can see why you are a ase master tech -- fmc mastertech . you guys will be hearing from me if I run into trouble . This is certainly a great forum. Thanks again