HELP, no spark on 1 and 5 cylinder 1997 ranger 4.0

[Trowe7]

Hey everyone, i am new to this thread. I just bought a 1997 ranger 4.0. Its running rough and i get no spark on 1 and 5 cylinder. I have changed plugs, wires, coil pack, crankshaft positioning sensor and checked voltage to coil pack. I sprayed carb cleaner everywhere and cannot find a vacuum leak. I am at a loss at this point. I cant figure out why i cannot get spark. Truck pulls P0351 code. Any help would be great thank you

 

[rangerenthiusiast]

Are you sure you’re not getting spark, or do you just know that you have a dead miss in those two cylinders? I only ask because I had a dead miss in cylinder 5 on my ’92 and it turned out to be the injector. I found a great deal on a set of rebuilt ones, so I pulled all my old ones and it cured the issue (they were disgusting). Just a thought.

 

[RonD]

#1 and #5 share one coil in the coil pack
{3 4}
{2 6}
{1 5}
Front

Thats why the spark plug wiring is the way it is, 1 2 3 and then 5 6 4

There are 4 wires hooked to the coil pack, 1 is 12volts, red one, when key is on.
The other 3 go to the computer and are the GROUNDS for each coil in the pack.

These coils work like every other ignition coil
They are Grounded to power up the Primary coil
Then Ground is lifted/cut, and Primary Field Collapses sending out high voltage spark on Secondary coil.

The 4 wires should be in order
12v
coil 3{3 4}
coil 2{2 6}
coil 1{1 5}

Or

coil 3
coil 2
coil 1
12v
You can test coil 1 wire, with a test light
Hook test light to 12volts and to coil 1 wire, test light should flash when you crank engine over, as computer Grounds that wire and ungrounds it.

If there is no flashing then wire is bad, or computer is
Test coil 2 or 3 to confirm they do flash test light

In 1997 coil 1 wire should be Yellow/black stripe, it goes to pin 26 on the computer