Detonation in the Rain

[herculesrider1]

I almost dread when it rains due to what seems like detonation, misfiring, missing that takes place when it rains. I saw a post from '08 from JoshieDoom but one thing that was not addressed was this: my issue makes the "service engine soon" light come on. It will do it for days after it stops raining, but when I floor it, it will not detonate or miss. Any help would be greatly appreciated, thanks.

[jodmari]

i almost dread when it rains due to what seems like detonation, misfiring, missing that takes place when it rains. I saw a post from '08 from joshiedoom but one thing that was not addressed was this: My issue makes the "service engine soon" light come on. It will do it for days after it stops raining, but when i floor it, it will not detonate or miss. Any help would be greatly appreciated, thanks.

i would start by changing ignition wires

[35th-ANV-SS]

Sounds like a bad wire to me that's getting wet. I would inspect the wires first before replacing them. One of them might be scorched. When you lift the hood, do you see any water sitting on anything?

[herculesrider1]

I'll check 35th. Thanks.

[tatertot91]

Running Longtubes? Sounds like your O2s are getting wet. Flooring it puts the car into open loop so that would change the running condition of the motor. I would have the codes scanned to be sure but i'm putting my money on an oxygen sensor

[cammed goat]

Running Longtubes? Sounds like your O2s are getting wet. Flooring it puts the car into open loop so that would change the running condition of the motor. I would have the codes scanned to be sure but i'm putting my money on an oxygen sensor

^^this

[herculesrider1]

Thanks Cammed and Tater, the next time it throws codes I will run to Advance Auto and have them put it on the analyzer.

[pajeff02]

I agree -- ignition wires and/or O2 harnesses. Not a bad idea to use a little dielectric grease on the plug boots and connections if you tear into it.

[theorangeguy]

I had an o2 sensor get wet and it caused the exact same issues, only mine was not an off and on problem...once it got wet, it had to be replaced. I disconnected the passenger side o2 sensor and water came out of the plug. I would make sure the actual connections for the o2's are tucked away so they are not overly exposed in the event that you do drive through sitting water. My o2 sensor itself was not the problem, it was where the connection was mounted that was causing my issue.

[pajeff02]

Dab some dielectric grease into the connectors before plugging it back together. Stops corrosion and prevents moisture from causing issues like that.

[herculesrider1]

Awesome information guys. I found a hole in the vacuum line of the PCV valve the size of a #2 pencil and thought that might be the source of my miss, but unfortunately it was not. Any recommendations on the ignition wires??? Thanks.

[pajeff02]

Lots of people use MSD wires. If you have headers, the boots can be bent for additional clearance. I always recommend the use of dielectric grease in the plug boots. Upon installation, you should hear/feel one "click" on the plugs and two "clicks" on the coil packs.

[herculesrider1]

Thanks Jeff. I have seen on Ebay some wires that are 8mm, 8.5mm, 10mm, with varying prices as well. Does it matter the size?

[herculesrider1]

Wow, could they have engineered it any harder to get to the #8 plug wire, I can only imagine trying to get the #8 plug out and back in.... I checked my plug wires and they looked good...the ones I could see that is. Well, it threw a code with the Service Engine Soon light, if it is still on, tmrw I will take it in and read the code... Nothing worse than having a car that is suppose to run like a scalded dog....run like a woulded one.

[pajeff02]

That measurement generally refers to how heavy the insulation is, not the conductor. Lots of advertising hype with ignition wires -- same for spark plugs. The wires on our cars are all short as they run from individual coils - if you have a specific wire set you are looking at post it up and you may get some feedback from other members. Again, the MSD wires are a solid choice.

As far as the plugs go, a few simple tips: Pop up the plastic pins that secure the cowl seal as they will shred your hands. Remove the coils packs from the valve covers. The last bolt on the passenger side is a bugger, but not too bad if you have patience. A 1-1/2" extension in your 3/8" ratchet seems to work best on the plugs. Go at number 8 from underneath the car - it was actually very easy from there, depending upon what exhaust you have.

[herculesrider1]

These are the wires I found on Ebay. Has anyone used these? I was looking for a wire that was prefabbed so that I would not have to cut and crimp.
And thanks Jeff, I will remember those tips.

[pajeff02]

Exactly what I installed on our car, only in black instead of red.

[GoldenFlame]

Yep! I run MSD's on both LS1's.

[herculesrider1]

Sweet. Thanks Jeff and Bear. Seems like the wires of choice. Looks like I'll be havin 'em on mine too!!