justin1889

I purchased a stock 99 FRC (with 47k miles) a couple months ago and lately have noticed when it gets warm it has a very noticable shake at idle. I put in new TR 55's, MSD wires, cleaned the TB and MAF, 2 tanks of lucas, and sea foamed. This past weekend I had a tuner hook it up to his laptop and everything look good. Does anyone have any idea what could be causing this?

blkbird

iTrader: (28)

My car had a little bit of a rough idle when I boutght it brand new. I dont think its anything to worry about. Does it surge or anything like that???

justin1889

It doesn't surge or anything abnormal when at any RPM other than idle. When I pull up to a stop light the car the car just has a very noticable idle to it that even the wife asks what it causing it to shake. I have only put about 1500 miles on it, but I am pretty sure it wasn't doing it when I purchased it.

Ragtop 99

iTrader: (7)

Is your car an automatic? They have really low idle speeds. bumping it 50 rpm helps.

I've also seen a 1/2 turn of the idle set screw help. Did you mess with it when you cleaned the TB?

rickyracer25

iTrader: (11)

I was thinking the same thing check the screw, also make so that all the vac. line that go to the TB is one as well as the PVC lines at the front and the back of the valve cover on the passenger side are plugged in. happened to my roommates Slowmaro SS when he changed the plugs it got disconnected when he took the coils off

DRSITES

iTrader: (3)

Just as a side note, I'm pretty sure that with vette's, being drive by wire and all, there is no idle screw; you'll have to tune the idle up.

justin1889

The car is a 6 speed and I am pretty sure there isn't an idle set screw. When I had it at the tuner he also checked everywhere for vacuum leaks and found none.

Street Lethal

The stumbling is occuring during Closed Loop, this is usually the beginning stages of a failing O2 sensor (regardless if the SES light is prevalent, or not). Have someone run another thorough check, preferrably your local GM dealer...

Ragtop 99

iTrader: (7)

I couldn't remember what year drive by wire started. I thought it was later than '99.