Running Rough and a P0306 code

SGaynor

Well-known member
Dec 6, 2006
7,148
162
52
Bristol, TN
UPDATE: New wires are in and truck is running smooth again. Turns out it was a bad connection on the #6 plug. Where the wire attaches to the connector in the boot, it pulled loose and was corroded.

The job wasn't that bad, actually. I didn't have to pull the intake, but the secondary air injection (SAI) tubes had to come out. That involved disconnecting the rubber hosing attached to the tubes, and one coolant line (to the heater core). Total job time was about 3.5 hours, but about an hour of that was spent figuring out how to remove the SAI tube, after that removal and installation of the plug wires was straightforward. I did however, mix up plugs 3/4 on the coil pack which required me to take everything back apart, swap the wires and reassemble - that took an hour. If I were to do it again, it would probably only take an hour to hour and a half.

Below is a write up on how I did it, and what "tricks" I found to be helpful. This procedure should apply to '03/'04 DIIs with SAI. As suggested above, putting a comforter down and laying across the engine, is the only way to go.


Remember, this is how I did it; use your own common sense when working on cars.

Removal and Replacement of Spark Plug Wires

Recommended Tools: Pliers, flat head screwdriver, spark plug boot puller tool (this is very helpful to remove the wires at both the plug and coil ends), 1/4 socket wrench, extensions, flex adapter, sockets (you'll need both SAE and metric), and a 10mm box wrench. A magnetic wand is also useful to pick up the bolts/nuts that drop down behind the engine.

1) Disconnect negative battery terminal

2) Remove rubber hose connections on the SAI pipe. There are three: two on the passenger side and one on the driver's side. The top hose connection on the passenger side is connected to a corrigated plastic tube, which is quite brittle. I cracked mine at the rubber hose connection, but it's got enough give to still be usable, just remove the piece inside the rubber tubing and reinsert the tube. You may also want to replace the quick clamp with a screw type hose clamp. The other two connections are to the SAI valves on each side of the engine.

3) At the back of the engine, pull the wire loom out of the three clips holding it to the body. Above the coil pack, disconnect the SAI pipe from the mounting bracket by undoing the two nuts using a 10mm box wrench. Then remove the bolts that hold the mounting plate to the engine, using the 1/4" drive with the flex connector (I don't think you can get it without the flex connection). Remove the mounting plate.

4) Disconnect the heater hose closest to the engine (there are two in parrellel) at the end closest to the radiator. Undo the quick clamp with a pair of pliers and move it to the metal pipe. NOTE: I had to cut the heater hose lengthwise along the metal tube to separate the hose and tube, but there is enough slack in the hose that with trimming that end off (~1") I could still use the hose. Besure to have a bucket underneath to collect the small amount of coolant that comes out.

5) Remove the SAI pipe. Yes, it does come out. Just be patient. Start by pushing it toward the driver's side and free the double pipe end by working it around the heater hoses, vacuum line and wire loom. With a twisting motion and some effort, pull the double pipe end out toward the front, then slide the single end out from behind the motor. It will come, just keep trying, but don't bend the pipe.

6) Now for the wires. I bought 8mm wires from Kingsborne. These were great - the wires were numbered at the coil end which made things much easier. I just pulled all the wires at once, then connected them at the coil pack two at a time, starting at the center-bottom (3/4), then outer-bottom, center-top, and center-outer. If your wires aren't numbered, you'll have to do them one at a time. I'd disconnect all the wires at the coil, then replace one at a time, removing from the spark plug to determine which wire goes where.

When removing the wires on the driver's side, it is helpful to disconnect the air intake hose at the throttle body (loosen the hose clamp and pull loose), and at the MAF/filter connection (two pull clamps). Moving this air intake up gives one a lot more room to get at the plugs/wires.

Here is where the spark plug boot puller tool was invaluble. It made disconnecting the wires at the coil a breeze. Just use it as a lever to pop off the wire. It would be difficult to do using your hands - there's not alot of space, especially for the bottom connections.

Installation of the wires at the coil can be tricky, but be paitent. It is also helpful to have the figure from the Rave CD/Workshop manual which shows the coil pack with the appropriate cylinder lead numbers. Just remember you are looking at a mirror image.

7) Once the wires are all connected, it time to put things back together. Start by putting the SAI pipe back in place. Again, some wiggling and patience will get the job done. Do not connect the rubber hoses yet, you'll need to move the pipe to connect the mounting plate. Connect the mounting plate to the engine, followed by connecting the mounting plate to the SAI pipe.

8) Reconnect the rubber hose connections to the SAI pipe. Reconnect the heater hose. Reconnect the air intake/MAF. Reconnect the negative battery terminal.

9) Start it up and see how she runs; check for codes. If you crossed wires, like I did:banghead:, you've got to do everything over again. But now you are a pro, and it won't take nearly as long.;)
 

crown14

Well-known member
May 11, 2006
6,288
4
Clayton, NC
I havent tried a 2dary truck like this, but I did sucessfully do a regular emissions truck like this:


Remove fan shroud cover and fan, remove engine mount nuts, jack up engine a little, pull the engine mounts out and lower the engine... acess to the coilpack is greatly increased. Be sure not to fuck up any of your other wires/hoses under the hood by stretching them or pinching them during the engine moving process.

Also, when working alongside the truck on something like this, deflate the front tires to gain easier access to the engine. Valve core removal tool makes this easy to do in less than 30 seconds, air compressor will have you back up shortly. Its worth it- just dont forget to air up the tires before driving off.
 

SGaynor

Well-known member
Dec 6, 2006
7,148
162
52
Bristol, TN
UPDATE:

After 6 1/2 years and 50000mi (4 yrs in MI, 1 in TX, 2 in NC) my Kingsborne plug wires gave up the ghost when the first cold snap hit a few weeks ago.

I bought new 8mm wires from Kingsborne for about the same price I paid 6 years ago. Still a very good value.