Car shaking ??

I got 97 rs no mod auto , it happent before after my mechanic change the timing belt and water pump, the reason is timing is off , so he fix that and my car run smooth , until now it been about 6 month , today i take the car so the freeway and run at 80 mph , after 20 min i stop the car at the red light , then i felt my car is shaking , and my muffler is sound different , like boom , boom , boom , and the car loss power, I pull over and turn off the car , pop the hood , let it cool down 20min , then I start the car my rpm is very low ,it usually go to #2 then drop down , now it go #1 then drop down. Any one know what happent here , it is bad to ride the car like this, thanks

check your ignition, especially the spark plugs, they might be corroded or fouled out. also try replacing the fuel filter.

just a thought, could it be motor mounts mabe.
I know my friends car was shaking bad then he got know ones and it was smooth

where is ignition locate , im new to engine stuff .

the ignition is like you're spark plugs, spark plug wires, ignition coil.

I just go to my car and take out the spark plug , and put it back on , tight it , and i turn on the car , well it stop shaking little bit now , it still shake little, i did change the the spark plug wire and fulse filter 2 weak ago, im happy with it , but my mom was mad cause i go turn on the car in the middle of the night , my muffler loud as hell :naughty: by the way do I need to change the ignition coil , when i bought the car it was 103k and now it was 115k it been about 2 year. What good If I change the ignition coil ( is this the black box that 4 spark plug wire connect too ? ) .

wow.. just off topic... what was the last year of english you have ever taken? It is kind of confusing to read your posts, killer7.

Perhaps his timing belt has slipped?!?

Sorry about my english , it suck . Today I take the car to the mechanic shop ( the one I alway been to ), He check my timing mark , change my spark plug to platium , put in a bottle of fuse inject clean , clean out the throat ( $40 total , each spark plug cost $6 ), but my car still shaking , he told me go fill up the tank ,and run like sh*t , well I listen to him , I went to the shell gas station and fill up the tank , then I take it to the road , saw a mustang gt, I stop at the red light ( my car shake like sh*T ), he stop at the red light too , at the green light , we both floor the gas , I beat him , then I come back to the shop, I stop the car , then I fell my car dont shake any more , the engine was quite , the muffler sound normal, the car run normal now, I wonder why ?.

i'm guessing it was your spark plugs then. you probably just needed new ones. you don't need to change the ignition coil unless it goes bad and yes, it's the black box connected to the 4 plug wires.

he did change the spark plug , to bosh platium , my car run great now, By the way , those platium spark plug , how to u check the gap , cause all 4 metal is close together ( I read the box , it say I never need to change the gap ) is this arite ?.

there's a certain tool for checking gap clearances on shit like that. if your mechanic is a good one, he should have done that anyways. i wouldn't worry about it if it runs good now.

On platinum, and Iridium plugs you dont touch the gapping because they are such a hard metal that moving it can cause damage.