Sparkplug design - sputtering

1999 - 70,000 mi
I'll try and keep this short....after many moons of dealing with hesitation, most noticeably when car was cruising then just give a little gas and the sputtering would be very noticable. Did the usual - replace plugs/wires and problem would go away for a week then return. Had cylinders tested and could see that one or two was misfiring on the read-out. Coil checked - all of the usual.

After inspecting one of the plugs I noticed heavy tracking - a black burn streak going from top of plug where wire attaches right down across the ceramic. Basically the spark was jumping around the ceramic. These are the platinum Delco's recommended for the car and the correct wires.

These plugs have a smooth ceramic surface; they don't have the "ribbed" surface like Champion. So I thought, what the hell, maybe if I try the Champions the spark may have a harder time jumping down the outside of the ceramic.

Well I must say - the cheap Champions have been running perfectly for 7 months. Maybe this is just coincidental but I went through 3 sets of the platinum’s with the tracking problem and now the problem has not returned.

do you ever hear a whistling type noise from your engine?? especially when its cold? You could possibly have an air lead from the side of your intake where the backfire flap is which causes lean/hot mix and burns up plugs too early. Had it happen to me....many others have also.

Interesting...I doubt the problem is with the cercamic though, most likly your plugs are getting fouled. The champions might run a little hotter though which keeps them cleaner and is solving your problem. I assume you are running just a copper plug, those in general less likly to get fouled up, as compared to platinum's The question though is why the plugs are getting fouled...

I actually run the bosch +2's and wires just because they were a little cheaper, haven't had any problems for 40,000 miles..

thanks for the replies.....

Actually I did notice a slight hissing sound when the engine was cold. Is there a particular place on the intake that is common for these air leaks? What is the backfire flap?

Yes, these are the coppers plugs. I'll bet that my performace has dropped slightly in the last 7 months since puuting these in, but at least there is no hesitation, spuddering...

J

I doubt your performace would drop, platinum plugs are in there for logevity, you know the 5 year 100,000 mile tuneup, coppers only last about 35k

You have to remove the gray plastic engine cover. On the passenger side of the intake(black plastic thing on top of engine with curved tubes) beside/behind the power steering pump there is a depression in the side of the intake. Inside that depression is a spring loaded flap. It basically protects the intake from breaking apart in the event of a backfire...gives it a place to let the pressure go. Anyways, the seal on these can go bad and cause the symptoms you are having. It took $25 for the part and an hour or two of work to fix. There are other things too though...like fuel pressure regulator, coils, wires....but if you hear a noise on cold mornings then it goes away after the car warms up a bit..I'll bet its the intake.