99 ford ranger 4cyl do those spark plugs on the exhaust side fire on the exhaust stroke or does it fire two plugs on the powerstroke?

 

The extra set of 4 just burns the exaust gas's.

 

My truck has dual plug head and right now it is only running on one side, the exhaust side. If those plugs fire on the exhaust stroke then my truck shouldn't run at all. I'm still checking it out but I would think the plugs should fire together or even better yet should fire one directly behind the other. Firing only on the exhaust side it does seem to be running a few degrees behind timing.

 

interesting

 

Got the intake side to work again, checking with a timing light they fire one right behind the other afew degrees. Reading in a few Ford books where they describe the operation of the distributor-less ignition , they describe how the coils will fire every time around firing two plugs for two different cylinders 180 degrees apart from each other. On one rotation it fires on the power stroke where it ignites the fuel, on the other rotation it fires on the end of the exhaust stroke where it does nothing - like the ignition on an old Harley. A six cylinder has three coils ( three sets of two plugs) an eight cylinder has four coils ( four sets of two plugs) a four cylinder with dual plug system has two coils ( two sets of two plugs) for each side that run a few degrees apart from each other.
The coils on an eight are timed so that it sparks as one line of eight whereas the dual plug four banger fires as two lines of four a few degrees apart to make for a longer spark. At least that is the way it should be, and that is the way it looks like it is.

The way it is worded in some of the books I had it is easily mistaken for the plugs on one side fire only on the exhaust stroke.

 

I have the 91 Ranger with the 2.3L 4cylidanr with 8 plugs. As Iunderstand it, the two plugs fire on the power stroke from opposite sides of the combustion chamber. The goal was to ignite a more powerful wave front and "bang" to get a stronger power stroke.

 

Yes, as I check into it even more , and study it closer with a timing light I see it looks as though both sides fire at exactly the same time after all.