hnaskoct

iTrader: (31)

ive been trying for the past wee, the car runs like crap. it sputter real bad and the engine light blinks and it throws code p0300 rando missfire.. i pulled a plug wire and cranked the car up to see it it sparks... it does nothing im wondering if it might be somewhere in the harness....

7camaro7

iTrader: (15)

might be a dead coil. since it is po300 it is multiple random misfires which means more than one. You will need at least one coil but it will probably be best to put 8 new coils, wires, and plugs. I had this situation before and it was all from a simple exhaust leak.

hnaskoct

iTrader: (31)

i have changed the plugs and wires 3 times ive changed the coils its like that coil pack plug isnt getting any fire

shoemike

iTrader: (25)

Check the harness, you may have popped a fusible link for that coil.

hnaskoct

iTrader: (31)

where on the harness should i start checking first

69LT1Bird

iTrader: (1)

No such thing.

Follow the coil wire back the connector that is attached to a bracket on the intake (one on each bank). Use a DMM to check the resistance of the wire going to the coil. You could have a loose terminal or broken wire. I don't have the schematic in front of me but it is a very simple circuit.

7camaro7

iTrader: (15)

did you change all 8 coils? When I had my issue I first did the evens 2.4.6.8 because that's where my fouled plugs were. My problem only got not as bad. Later I did my other 4 coils and the problem disappeared.

RPOWU8

iTrader: (13)

Did you clean the wires going to the coil packs? There is a gray 7 pin connector where the coil pack harness meets the main harness and the connectors can get oxidized. Usually just moving the connector around will tell you if you have a problem there. You will need to clean or replace the pins.

Make sure you check the fuse block under the hood first as there is a seperate fuse for each side.

Don't drive it around as you will wash the cylinders dry with raw fuel.

Good luck

Dee Jay

shoemike

iTrader: (25)

There are fusible links all thru the coils wiring.

69LT1Bird

iTrader: (1)

Show me where. We are talking about the harness, not the physical coil.

Each bank shares a common ground using a splice.
Each bank shares a common ignition circuit feed using a splice.
Each bank shares a common Low Reference signal using a splice.
Each coil has a separate input signal from the PCM.

So the 7 pin connector has the 4 individual coil signal wires from the PCM, common ignition voltage, low ref signal and ground.

shoemike

iTrader: (25)

Is this enough proof for you?

If there is an open in the coil harness most likely one of these gave out.
As I said in post #4
check the harness I never said the coil itself,
fusible links do exist.

69LT1Bird

iTrader: (1)

That is called a splice pack. Not trying to get into a pissing match with you but I don't want someone looking for a fusible link when one does not exist.

shoemike

iTrader: (25)

I seemed to have confused the two.
They are not the same thing?
Do these give any circuit protection?

69LT1Bird

iTrader: (1)

A splice is designed to join several circuits into one. Like the coils on the LS1 engines so they can share ignition voltage from a common source, cheaper than running separate power feeds to each coil. They provide no circuit protection.

Fusible links are designed to melt a certain temperature based on a predetermined circuit overload.