vibration at Idling

[97GreenGTP]

Hello Everyone,
I have a 97 GTP. Just last weekend, I crossed the 200,000 mark. When I got Pirelli's on it at 95,000 miles, I never expected the car to last long enough to get new tires. But couple of months ago, I got new set of Pirelli's on. The guy at the counter said that the car wont last to wear this set. I am keeping my fingers crossed and hoping to wear that set and I am confident. She runs good so far.
Lately, the idling has been rough though. It doesn't try to die but I feel some vibration in the engine ( I am too picky too.. ). I had spark plugs and wires changed at about 100 K and injectors cleaner added to fuel about 50 K ago.

Any suggestions on what might cause that would be appreciated.

[tblake]

Vacuum Leak - Do you have access to any OBD scanners that display fuel trim readings.

Could also rent a fuel pressure guage and do a pressure check and make sure its within spec.

Possable might want to take it to the dealership and have GM do a top engine cleaning on it. It usually does a really good job.

[wlkjr]

Originally Posted by 97GreenGTP

Hello Everyone,
I have a 97 GTP. Just last weekend, I crossed the 200,000 mark. When I got Pirelli's on it at 95,000 miles, I never expected the car to last long enough to get new tires. But couple of months ago, I got new set of Pirelli's on. The guy at the counter said that the car wont last to wear this set. I am keeping my fingers crossed and hoping to wear that set and I am confident. She runs good so far.
Lately, the idling has been rough though. It doesn't try to die but I feel some vibration in the engine ( I am too picky too.. ). I had spark plugs and wires changed at about 100 K and injectors cleaner added to fuel about 50 K ago.

Any suggestions on what might cause that would be appreciated.

With care there is no reason to believe it won't last another 150,00 miles. That's another couple sets of tires or more.

[grandprixgtx00]

you havent changed the plugs and wires in 100K. i would do another tune up, maybe put some injector cleaner in the tank. also...change the fuel filter, its also due.

[tblake]

Clean up the throttle plates, IAC, and MAF with the appropriate cleaners.