Car still vibrates at stop (FIXED: EGR)

So my 96 sc, I replaced the spark plugs and wires recently but before all this it vibrated like crazy at low rpm, then I changed the spark plugs and wires and it's soon much better now but still vibrates unusually, could it be the supercharger coupler? Or anything else?

check the harmonic balancer for tears in the rubber.

Does it idle okay in Neutral but not Drive? Or is it rough all the time at idle?

In neutral it idles at 1800 just fine, but in drive it's rough, it's always rough when it's in final drive going about 50mph bc the rpm is at 1500 if that makes sense. And I cleaned the things the spark plug wires connect to. I'm still learning about cars so sorry about my knowledge

Harmonic balancers?

It idles at 1800 in neutral?

Does it shift hard? Does it pull strong while at a stop sign?

how bads the vibration
my car did that at idle and it turns outmy rear engine mount was shot so my stock downpipe was sitting on the sway bar

It pulls hard, I love it, and it idles at 1800 in neutral bc my erg tube is broken, I ordered a new one to fix the vacuum leak. And it does shift pretty hard, transmission slipped pretty bad if I take a corner fast and floor it.

The vibration feels like it still misfires but nearly as bad

A vacuum leak will cause the car to run rough at low RPMs. My 2003 Pontiac Vibe idled rough with just a minor vacuum leak. The leak caused a multiple cylinder misfires code.

Yesss I was hoping that's the reason, I get my egr tube Wednesday I'll let you guys know if that fixes everything! Thanks for all your help!

So you know you have a huge vacuum leak and broken EGR tube and you are still asking us to help you diagnose a rough idle? You should probably have added that info to your first post... it's kind of a big factor. The problem could be your broken EGR tube and big vacuum leak.

Yah sorry guys, it's a small whole but I didn't think vacuum leaks could cause rough idles, I just thought it would idle high because of it. Sorry

When I fix it in a couple days I'll let you guys know if that fixes everything

You should enable your signature and include the year of your car (even though you have it as your name), list any and all mods there, supercharged or not. Then anytime you ask for help on something, make sure you tell us about everything going on, not just part of it. Critical parts if you want good advice.

Oh ok good idea now I see why you guys have that ok thanks!

so everything is together, perfectly, car is running smooth as butter, thanks guys!

bmcd9179 wrote:

so everything is together, perfectly, car is running smooth as butter, thanks guys!

Just to clarify - after replacing the EGR tube?

Yes sir! My egr tube had a big crack in it, the car idles perfect now, and is keeping a better temp on my gauge, it used to raise pretty fast for some reason, then cool back down but, now it stays at 180 to 185. I'm also getting better mileage. Just so you guys know

Glad to hear you got it figured out

i'm glad too brother....

bmcd9179 wrote:

Yes sir! My egr tube had a big crack in it, the car idles perfect now, and is keeping a better temp on my gauge, it used to raise pretty fast for some reason, then cool back down but, now it stays at 180 to 185. I'm also getting better mileage. Just so you guys know

Good news. Thanks for filling in the details!