95 shuddering while idle

As of recently (1 or 2 days) my van has begun to shudder while idling, and at initial acceleration. Any ideas of what the problem may be?

maybe spark plugs? coils?

Thanks

maybe spark plugs? coils?
Certainly spark plugs and wires are "normal" prime suspects...depending of your knowledge of previous maintenance. If wires are original, new are a must.

we've replaced the wires previously, and 1 coil pack. The only thing I've noticed with one of the coils is that it doesn't fit "snug" to one of the coil packs, but if I remove that wire the engine will start having a hard time...

However as of now, the car isn't shuddering?!?! The day it started I filled up gas at this one place. Filled it right to the top (over fill), then I added some gas line anti-freeze..?!?! but since the gas has gone down to about half now, the car isn't shuddering...

weird..

...must be fuel from the tar sands...:evillol:

bump...

this time i just washed the engine?!

covered just the alternator though..

LMP.. this one is for you lol