Originally Posted by JoeTaylor

I have worked with high voltage (electrostatic separators) and when I read your post, the first thing that came to mind was - moisture.

All plastics absorb moisture from the humidity in the air to some extent or another. Some plastics are more hydroscopic than others

In my former business, we were very familiar with the phenomena here in humid Florida. The mantra is "tempurature cures all".

Once the ignition wire(s) heat up, the surface moisture on the insulation starts to dry off. So when the engine is hot, the heat of the engine drives off and keeps away the surface moisture.

Next day, after the engine cools overnight, the moisture from the air absorbs again into the insulation.

The way to check this is to use a hair dryer and dry off all the wires while the engine is cold first thing in the morning. The wire insulation should get hot enough you can feel it with you fingers... but not too hot. Then try cranking up your engine.

If the problem goes away... haha, blame it on the dew and humidity.

Joe

Originally Posted by AO

Have you pulled your spark plugs and looked at them?

When it's running like crap, shut off the engine, and pull the plugs. You should be able to tell which cylinders are the culprit and narrow it down. If it's all 4, it's either the cap, rotor, coil, or final stage (the thing that's at the very front of the engine on the driver side).

If it's just one or two plugs, then it's further back (although the cap and rotor could still be suspect).

Originally Posted by WallyP

The Temp II Sensor may be faulty. On the top of the engine, near the front just off of center, there is a sensor screwed into the engine, with two wires in the harness. There are two identical temperature sensors, one for the ignition and one for the injection. Check the resistance of each pin to ground not from pin-to-pin. The resistance at specified engine temps should be:
32 deg F - 4.4 to 6.8 kOhms
60 to 85 deg F - 1.4 to 3.6 kOhms
104 deg F - 0.9 to 1.3 kOhms
140 deg F - 480 to 720 Ohms
176 deg F - 250 to 390 Ohms

Originally Posted by the flyin' scotsman

Read Dwaynes intake R&R.....he came up with a tool thats used to pressurise the intake system to detect leaks.....have fun.

Originally Posted by fraggle

How new are the plug wires? Based on the moisture/high voltage experience input, maybe a set on the way out is more susceptible. You just moved the problem from the coil wire up to the sparkplug wires.

Originally Posted by cpayne

After arriving home from training. It was very nice all day here.
I thought this would be a great time to test the moisture theory. Started it up. Let the temp gauge start moving as normal. Car didn't exhibit any symptoms of rough running at all. mornings where it was colder raining produce the rough running condition. I don't know if this is conclusive or not. I'm going to try again tomorrow. I don't now if this is related but when I let my foot off the gas in any gear as the car slows it jerks almost feels like its cutting out rapidly, almost like a down shift or when your going slow in a parking lot in a 1st gear ((Manual) and reach a point when you have to press the clutch or the car bucks. At least mine does.

Thanks

Originally Posted by Jadz928

Charles,
What is the moisture theory? In particular, what does it point to?

Originally Posted by cpayne

See post #16

Originally Posted by Jadz928

Charles, I have the intake pressure test tool you can use.

Originally Posted by cpayne

Yep I have all those marked. looks like a trip to HD plumbing section

Originally Posted by Jadz928

Oh I see. So how was your test conclusive?
I'm not a scientist, but wouldn't it be more conclusive to perform the test when the problem occurs?