Ignition Coil Problem

[jfin2017]

1998 5.0..truck completely lost power and stalled. Would crank but not fire. I got towed home and assumed a fuel issue. Replaced the fuel pump and no luck. Then I looked at the camshaft sensor. Sensor was broke and bent the flag on the synchronizer. Replaced both of those still no luck. I stabbed the synchronizer like 6 times and pretty sure I had it right the first time. #1 cylinder was at TDC and synchronizer dropped in and pointed exactly how I removed it. Still cranking no fire. Then I replaced the crankshaft sensor. Again cranking and not firing. Then I realized the mounting bracket for the coils had to be attached for them to ground properly. Started it and it ran but like crap. Looked under the hood and realized I didn’t plug in the passenger side coil pack. Plugged it in and crank no fire again. Thought maybe the passenger coil was fried so I swapped them. Still having the same issue. The vehicle will not start with the passenger side coil plugged in. I checked it with a multimeter and it’s getting 12V to the connector. I’ve read everywhere and can’t find someone with the same problem. Someone plz help me lol

 

[amj441]

the vehicle wont "start" with the passenger coil connected at all, even after the coil pack was moved to the driverside connector? Does it still "fire" with just the driveside coil plugged into the passenger side? sounds like you a did a good job diagnosing it and it is most likely the coil pack is internally shorted.

You might just need a new coil pack lol

 

[410Fortune]

Did you use alignment tool when you installed the cam synchronizer?
Cylinder one must be at tdc on compression stroke the synchronizer is stabbed to the camshaft with alignment tool

The crank sensor is the one that really controls the spark, the cam sensor only used for timing

Should have tested for fuel pressure before replacing the pump

So Let’s start with the basics
Does the check engine light come on with the key and go off when cranking the starter?

Does the theft light flash normally and then go off when cranking the starter?

 

[jfin2017]

the vehicle wont "start" with the passenger coil connected at all, even after the coil pack was moved to the driverside connector? Does it still "fire" with just the driveside coil plugged into the passenger side? sounds like you a did a good job diagnosing it and it is most likely the coil pack is internally shorted.

You might just need a new coil pack lol

Yeah I’m still having the same issue after swapping them. Truck won’t fire (start) after swapping them. Makes me think it’s something else and not the coil packs

 

[jfin2017]

Did you use alignment tool when you installed the cam synchronizer?
Cylinder one must be at tdc on compression stroke the synchronizer is stabbed to the camshaft with alignment tool

The crank sensor is the one that really controls the spark, the cam sensor only used for timing

Should have tested for fuel pressure before replacing the pump

So Let’s start with the basics
Does the check engine light come on with the key and go off when cranking the starter?

Does the theft light flash normally and then go off when cranking the starter?

Yup used the alignment tool and the #1 piston was at TDC on the compression stroke. I even unplugged the camshaft sensor and it still ran. Don’t think it has anything to do with that. Check engine light comes on with the key on and goes off when cranking. Also it’s not a pats issue. Theft light goes off when cranking. Plus it will run as long as the passenger side coil isnt connected.

 

[410Fortune]

Have you tried a new coil pack?

@amj411 was probably Right

Sounds Like that one has a short in it

The theft light going off means the pats system is happy with the key
The check engine light going off means the pcm is powered and it is seeing a signal from the crank sensor when engine rotates

Quite possibly you lost a coil pack when the old cam synchro went south

 

[jfin2017]

I just don’t understand why it does the same thing when I swap them. They’ll both operate 4 cylinders as long as they’re on the driver side. I went ahead and ordered coils so fingers crossed.

 

[410Fortune]

They are actually only 2 coils in each one these engines are batch fire / waste spark ignition so two cyl fire at same time

You could check the wires between the pcm and coil pack make sure there is continuity

 

[jfin2017]

They are actually only 2 coils in each one these engines are batch fire / waste spark ignition so two cyl fire at same time

You could check the wires between the pcm and coil pack make sure there is continuity

Just replaced the coils. Still doing the same thing. It acts like it wants to kinda start now for a sec then just keeps cranking again. I wonder if it’s possible that the plugs and wires need to be replaced now too with the way the spark fires? I feel like I’m getting closer lol

 

[amj441]

I just don’t understand why it does the same thing when I swap them. They’ll both operate 4 cylinders as long as they’re on the driver side. I went ahead and ordered coils so fingers crossed.

THIS is key information. BOTH will operate 4 cylinders as long as they are both on the drivers side but NOT when on the passenger side. This would indicate either a problem with the wiring or the pcm rather than a coil.

Spoiler: Coil Wiring Diagram

I would check power at the passenger coil. and trace the radio noise capacitor and make sure its where its supposed to be.
I would then check the continuity of all of the signal wires to make sure one isnt permanently grounded.

red/light blue
dark blue/lt green
pink/wht
red/yellow

These are all ground trigger wires that are grounded by the pcm to "fire" the coil

Red/light green should be your 12v feed to charge the coil.

EDIT:
Also an afterthought, Check the big pcm connector for looseness or signs of corrosion as it will be easier than probing the wires first