Alright im gonna make this short and sweet. My car is vibrating heavily at idle and under load. I figured it was a coil pack that had gone bad so I changed those out since i had a spare set. Didn't solve the problem. So today i did spark plug and found a couple of bad ones and one really wet one. You will be able to see it in the pictures below. Let me know what else you think it could be since its really annoying and its my daily driver. My next reasoning will think its wires but they didnt look bad to me. Also i thought it might be a leaky injector but i know nothing about what to look for on that. It was just a guess.

You can't tell a bad wire by looking at it.

99% of all stumbling problems are ignition-related. Rarely do we see injector issues.

If you don't know how old the wires are, or you know they're over 50k or so, change them. In the future, it'* best to lay your plugs out like that in order. If you do that, please state WHAT order they are in. That way we can isolate known problems based on the firing pattern, location, other factors.

Yes. I vote for wires. My experience is that the wires will fail before the plugs get so bad it misses. And... just the process of replacing plugs is likely to cause "human induced" wire failure. If you run it long it will get all fouled looking, just like that nasty one.

If you want more assurance, you can pull the wires off the coils one at a time, with motor running and IAC unplugged. The miss will either get worse or stay the same. Of course, when the miss does NOT get worse with a wire off, that is one of your bad plugs, wires or coils. I'm a chicken, so I like to use rubber handled pliers and rubber gloves. It will still give you a little tickle when the wire is put back on.
Call me "Sparky."

that really bad one came from the number 4 cylinder if that helps. I think my next step was gonna be wires since the last time i changed them it was about 40k ago. I also forgot to mention the exhaust smells really funny since this has happened. The only thing is though is it seems like its firing all 6 cylinders.

also where is the IAC located? I have never taken it off before.

on the throttle body. im sure someone could dig up a picture... bit its on the front of the TB.

you mentioned bad exhaust smell, could possibly be the cat? rotten egg smell?

no i dont think its rotten egg smelling. i will have to check. if i remember right it just smelled hot. It could be wires, i think i still will try them unless anyones got any other ideas. The exhaust when the car runs is making a thump noise (I dont know how to explain it) so it could be not firing in one of the cylinders, i would think it would throw a code though and it hasnt. I wish it would :(

It doesn't smell like coolant, does it? With the car cold, check the coolant level in the radiator and the expansion tank. Radiator should be up to the cap. Are those levels okay?

I think you are right - the thump sound in the exhaust is just the sound of one cylinder misfiring.

no its not coolant. i havent been missing any i checked that already. Its also not blowing white smoke. I already had the plenum failure and that was a bummer since it hydrolocked my engine but amazingly still runs so i was lucky on that. Im gonna try wires since they are not really that expensive and get back to you. Its also been about 40,000 since they were changed last since i changed them when i bought the car. Im gonna try and get them today and get them done.

Here is where it is on my 93


It has a hex thing, where it screws in like this one

Is that for the S1 or S2? I have the S2