Questions About My Idle
Thread Starter
Intermediate
Joined: Sep 2003
Posts: 35
Likes: 2
From: Nashville TN
Questions About My Idle
I bought a 2000 Corvette about 3 months ago and as best I can tell, it is completely stock. It only had 23K miles and the car is in pristine condition inside and out, so I know it was taken care of. Here is my dilemma... it has what I call a "miss" when it's idling and when you are shifting gears on the acceleration, it has a sputtering "blowback" when you push the clutch to upshift, a very loud noticeable one I believe. I have asked other Corvette owners and even the local Chevrolet garage about this and they say that the H Pipe is too small and that ALL C5 Corvettes do this. I find that hard to believe, it just seems too loud and not nearly as smooth as a Corvette should be on the acceleration. Does anyone have any ideas on this? Any help or input would be greatly appreciated. I can't believe with that few miles that it would need new plugs or wires, but I guess it is possible. I now have 28K miles and it is getting more pronounced as time goes by. Could it be the ignition module? Help....
Le Mans Master
Joined: Oct 1999
Posts: 8,205
Likes: 40
From: Tucson AZ
Re: Questions About My Idle (chasintn)
I can't believe with that few miles that it would need new plugs or wires, but I guess it is possible. I now have 28K miles and it is getting more pronounced as time goes by. Could it be the ignition module? Help....
Burning Brakes
Joined: Feb 1999
Posts: 1,165
Likes: 1
From: San Jose CA
Re: Questions About My Idle (chasintn)
All LS1 Vette engines run a little rough at idle. It's normal.
If you get a misfire during driving, the Check Engine light will flash. Does it do this?
Another possibility might be the plugs. If you have stock plugs ( AC Delco platinum) check for missing pucks. These stock plugs are notorious for loosing the pucks , leaving you with a too wide sparkplug gap. Change em all with NGK TR55IX
The previous owner might have used an aftermarket airfilter such as K&N but put the stock airbox back on when he sold the car. In this case you may want to clean the heated wire in the MAF. Some of the filter oil deposited itself on the wire, so the PCM can't correctly measure the amount of air to get the optimal A/F ratio.
As stated by others, check the sparkplug boots. You might think they are correctly put on but in reality, they aren't. Specially the #7 and 8 plugs are kinda hard to get to, so I'd check these 2 first.
Hope this helps
Roger
If you get a misfire during driving, the Check Engine light will flash. Does it do this?
Another possibility might be the plugs. If you have stock plugs ( AC Delco platinum) check for missing pucks. These stock plugs are notorious for loosing the pucks , leaving you with a too wide sparkplug gap. Change em all with NGK TR55IX
The previous owner might have used an aftermarket airfilter such as K&N but put the stock airbox back on when he sold the car. In this case you may want to clean the heated wire in the MAF. Some of the filter oil deposited itself on the wire, so the PCM can't correctly measure the amount of air to get the optimal A/F ratio.
As stated by others, check the sparkplug boots. You might think they are correctly put on but in reality, they aren't. Specially the #7 and 8 plugs are kinda hard to get to, so I'd check these 2 first.
Hope this helps
Roger
Race Director
Joined: Sep 2001
Posts: 11,907
Likes: 1
From: Between a rock and a hard place, S.E. PA
Re: Questions About My Idle (chasintn)
In the last month, my 98 developed a rough idle and a pulsing sound on accelleration. It's been to 4 shops, had the cats replaced under warranty (finally, which resolved a different problem), Corsa exhaust removed, dyno tuned, injectors temporarily swapped, new plugs & wires, compression test, checked for bent rods, and the fuel filter replaced.
Almost $2000 later... the car still has the same symptoms. My advice is to check or replace the things you can do yourself or have all regular maintenance jobs performed like... plugs, wires, and filters. Other than that, turn up the stereo to drown out the noises and drive it until something explodes. OK, so that's the point I'm up to, your mileage may vary.
Almost $2000 later... the car still has the same symptoms. My advice is to check or replace the things you can do yourself or have all regular maintenance jobs performed like... plugs, wires, and filters. Other than that, turn up the stereo to drown out the noises and drive it until something explodes. OK, so that's the point I'm up to, your mileage may vary.
