Power loss w/new plugs

[fkirk1]

Just got my '94 ATX SHO about 2 months ago. Has 90K miles, 1 owner, in very good condition. I washed the back side of the engine with cleaner & then sprayed it off w/water recently & developed a low RPM skip. Yep, a little water got in plug well #4. I cleaned the plug wells out, pulled the Autolite xxxx32PP plugs & found them to be worn a good bit so I installed new Autolite single platinums of the same value (xxxx32P). The old plugs were worn to about .056" but clean. I gapped the new ones to spec (.042") & installed. Skip is gone, runs smoothe, but I've lost 10-15% of my low end power. I have a theory of why the power loss but I'd like you wisdom & experience here. I'll say up front that I haven't seen any documented evidence that double platinums ignite with a hotter spark so I don't believe that is the difference. Why the power loss & how do I fix it?

 

[SHOkid13]

I'm not a real big expert in this area, but it sounds to me like it is due to the smaller gap. The reason for running a bigger gap is to assist in burning more fuel. The reason to run a smaller gap is to keep the coils from going out early. (More gap, more resistance, more heat, more electrical damage)

I just replaced my plugs and wires with the stock ford plats and taylor spiros. I noticed quite a bit better idle and a better low end launch. I think my old wires were pretty crappy.

Matt

 

[MOSHO92]

Well, I guess you learned your lesson about spraying these motors with water... Not the best way to clean it. Just grab some simple green and a bunch of towels.

About the power loss... If you really feel that 10-15% of your power is gone I'd be inclined to say that there is a problem. You could have damaged one of the plug wires by getting them wet. How old are the wires anyways?....

 

[olympic]

As quote4d from www.shotimes.com

Do not use any plugs other than the stock Motorcraft platinum plugs (Motorcraft AGSP32PP, sometimes designated AGSP32P+). Available aftermarket "alternatives" do not have the correct geometry to allow the plug wires to seal the plug well off from water and other contaminants. If you do use non-Motorcraft plugs, expect to be replacing at least your plugs and wires again in short order.
Replacement Motorcraft plugs are not identical to the originally installed plugs. The replacement plugs have platinum plating on both the tip and the ground electrode of plugs. The original plugs only have plating on one surface: three plugs have plating on the tip and three plugs have plating on the ground electrode. This is a cost saving measure for Ford.

The DIS module uses three coils to fire the six plugs. Each coil fires 2 plugs at the same time. The current leaves the coil, goes through one spark plug tip, sparks to the ground electrode, goes through the block, comes up the ground electrode of the return plug, sparks to the tip, and flows back to the coil. This causes most of the wear to be on the tip of one plug and the ground elctrode of the other plug.

The ramifications of all this are if you are removing the original plugs and are not replacing them then make sure you replace the same plug in the same location or the DIS module will not see a balanced impedance and improper ignition will result.

So those Autolite single platinums will work OK for a while but they won't last long.

Your spark plug wires may have been damaged due to the arcing that occurred when the water was in the plug well.

 

[twr]

Further more And speaking from experience - do try to use the Champions (crapions) double platinums. They will foul out under 1K miles. I tried them in a pinch and replaced them within a month with the motorcrafts.

 

[autobahnsho]

I would check the wires. If the car is running ok but then you move something around (IE unplugging the wires, then plugging them back on) maybe the connection isn't good, or something broke inside.

If they are cracked at all, they will definitely cause you problems.