Would a bad fuel injector cause plug not to fire? Weird voltages at harness for cylinder 3 compared to other cylinders. No spark at plug. Coil and plug new and tested on other cylinders. I am leaning toward computer. Any ideas?
As they are 'pencil coils' on your vehicle, you can transfer the supect coil on to a differant plug. If the coil now works correctly whilst the one it was swopped with starts to 'misfire' on number three plug then you know you are dealing with a fault with No.3 cylinder. Secondly try replacing No3 spark plug with one you have removed and know to be working previously. Thirdly, unplug the No 3 injector-just the electrical connection- and measure its resistence with an Ohm meter. Now compare the resistence of any other injector. Your injector is a simple solonoid and can be tested with an Ohm meter. Open circuit on number 3 injector, or a very much lower reading will pinpoint a faulty injector. If every thing runs to expectations then you very well may have a fault on your wiring harness, or blown power diode(s) in your ECU. In this case, and before deciding on any expensive expenditure, have the vehicle scanned with an OEM/compatable scanner. If you have an analogue volt-amp set, do not use it on any modern vehicle. Its low internal resistence will allow it burn out modern electronics. In passing, an Ohm meter must never be used on any vehicle circuit that includes a Hall generator (three wire sensors for example), as the Ohm meters testing voltage will destroy the Hall generator.
On Chryslers it's the other way around. When the PCM detects concurrent misfires on a cylinder it'll shutdown injector pulse.
Check pin 1 on the coil harness tan/orange for signal from the PCM and pin 7 on PCM connector 2. If you're seeing voltage drop on the power side of the coil you're gonna have to unwrap some tape and check your splice and wiring.
If the coil keeps burning through check for cracks inside the threads of spark hole. Sometimes it so small it cant be seen an even the Dodge dealer couldn't find it. Need to inspect with bore cams.