93 buick lesabre, stutter and vibration

OK. I have a 93 lesabre, 6 cyl. For a while it's been stuttering when accelerating. The check engine light comes on and goes off. When I accelerated slowly it would stutter bad but accelerating hard it was smoother.
This morning it began vibrating badly at 55 to 60 mph at first, I turned it around to get home and take my wifes car to work. Now just idling it vibrates as if it's missing terribly.

I can't afford a garage, I'm in the process of bankruptcy and need to fix it as cheap as possible.
One other thing. I did notice a coil pack arcing a week ago. Not sure if this is related to all the problems or if I have multiple problems.
Reasearching on the internet says it's possibly the throttle position sensor. Would that also cause the bad vibration in idle?
Would the coil pack going bad cause the same problems?
I thought the vibration was a bad tire but it does it while parked and idling so it's not that.

Ideas?

thanks a ton for any help
jim

 

Well for starters, the arcing would not be a good thing, but before you go any further it would really be a good idea to read the codes. It's DIY-able on your OBD-I Buick. The procedure is here:

http://www.troublecodes.net/GM/

Bad coil pack(s) or bad/clogged injector(s) would be on the list of possible causes in addition to more basic items like plugs & plug wires.

 

Better check out that arcing, in the dark. You may be able to cure that simply by repositioning a wire. Arc could be jumping to some kind of dirt/carbon, also, - so you may have to clean the area where it is arcing. You don't want arcing.

Then if you are cheap, you could ohms test all your wires to at least see if they are all pretty uniform. They have quite a high resistance just so you are aware of that. On a digital voltmeter you have to set the scale into the thousands to get a reading. You want consistency amongst all of them. Then I'd pull the plugs, if I was you.

 

I pulled the plug wires off the suspect coil pack.It didn't run any worse, still vibrated.When I put plug wires back on it ran no different. Also one of the coil pack posts that the plug wire plugs onto was rusty. I cleaned it off and no difference.

The arcing was mainly when it was wet out. I noticed it when I checked fluids before going to work and it was dark out. It was arcing right on top of the plug wires from one wire to the next.

Are coil packs a common prlblem with this engine? I've had some replaced twice before, one each time, not sure if it was same one or not.

Jim

 

Does it SPARK though, out of that coil packs plug wire? If not, then coil pack or wire. If yes, dead cylinder or bad plug allowing current to flow to ground without sparking, such as if insulator is cracked, carboned, etc. down inside the combustion chamber, or sometimes if insulator is real dirty or cracked on the outside, also.

 

My suspicion is that your plug wires are toast.

 

Took to garage as I couldn't get some of the plug wires off due to tight space. All wires were replaced, then plugs. Still missed some when they took it out for road test.
Coil pack was also bad and replaced. Same one I suspected. replaced it with used one to save money. Still cost me $200 total. Ouch. That might be reasonable considering the wires and plugs and labor also but the timing couldn't have been worse.
thanks for the help everyone. I appreciate it.

jimco