LS3 Engine Concerns!
Thread Starter
Racer
Joined: Feb 2007
Posts: 315
Likes: 9
From: Cocoa Beach Florida
LS3 Engine Concerns!
Anyone have/had concerns like me??
50 to 100 RPM range varies while stopped in gear (A6), (500 MPH to 600 MPH),
MPG lower than what it should be (22 MPG vs 26 MPG),
When going down a steep hill, the vehicle reduces speed without using the brakes
Thanks!
50 to 100 RPM range varies while stopped in gear (A6), (500 MPH to 600 MPH),
MPG lower than what it should be (22 MPG vs 26 MPG),
When going down a steep hill, the vehicle reduces speed without using the brakes
Thanks!
Safety Car
Joined: Apr 2006
Posts: 4,254
Likes: 5
From: Anaheim Hills, Ca
Sorry....I couldn't resist!!
Going down a hill or decelerating with no pressure on the gas pedal, the fuel will actually shut off after a short period if you keep your foot off it. That's when you see your instant fuel mileage spike up to 99 MPG. So that is normal.
Your idling RPM variance might need to be checked although if your a/c is cycling, that will vary it for an instant until the ECM brings in throttle to bring your RPM back up.
26 MPG is under ideal conditions; depending on how you drive, the mileage will vary considerably. How many miles on the car?
Thread Starter
Racer
Joined: Feb 2007
Posts: 315
Likes: 9
From: Cocoa Beach Florida
I think you have a real problem. Mine runs smooth as silk at over 500 MPH!!
Sorry....I couldn't resist!!
Going down a hill or decelerating with no pressure on the gas pedal, the fuel will actually shut off after a short period if you keep your foot off it. That's when you see your instant fuel mileage spike up to 99 MPG. So that is normal.
Your idling RPM variance might need to be checked although if your a/c is cycling, that will vary it for an instant until the ECM brings in throttle to bring your RPM back up.
26 MPG is under ideal conditions; depending on how you drive, the mileage will vary considerably. How many miles on the car?
Sorry....I couldn't resist!!
Going down a hill or decelerating with no pressure on the gas pedal, the fuel will actually shut off after a short period if you keep your foot off it. That's when you see your instant fuel mileage spike up to 99 MPG. So that is normal.
Your idling RPM variance might need to be checked although if your a/c is cycling, that will vary it for an instant until the ECM brings in throttle to bring your RPM back up.
26 MPG is under ideal conditions; depending on how you drive, the mileage will vary considerably. How many miles on the car?
2. My '98 coupe and my '03 ragtop would INCREASE the speed going down steep Monteagle Mountain (on I-24). They would increase the speed to about 92 MPH with 99 MPG. My '10 ragtop DECREASES downhill for about three miles!
3. The idle RPM (and everything else) was checked and while the test, the RPM was 500 (A/C on and off)...just like yours! The history did not show anything!
4. I drive to save the MPG...cruise control on almost every road (except heavy traffic).
5. She now has 14,000 miles.
Thanks for you thoughts and if you have more, please let me know!
Thread Starter
Racer
Joined: Feb 2007
Posts: 315
Likes: 9
From: Cocoa Beach Florida
1. My '98 coupe and my '03 ragtop had 28.2 and 27.5 mpg respectively on highway speed. My '10 ragtop gets about 22 mpg on highway and local street speed!
2. My '98 coupe and my '03 ragtop would increase the speed going down steep monteagle mountain (on i-24). They would increase the speed to about 92 mph with 99 mpg. My '10 ragtop decreases downhill for about three miles!
3. The idle rpm (and everything else) was checked and while the test, the rpm was 500 (a/c on and off)...just like yours! The history did not show anything!
4. I drive to save the mpg...cruise control on almost every road (except heavy traffic).
5. She now has 14,000 miles.
Thanks for you thoughts and if you have more, please let me know!
2. My '98 coupe and my '03 ragtop would increase the speed going down steep monteagle mountain (on i-24). They would increase the speed to about 92 mph with 99 mpg. My '10 ragtop decreases downhill for about three miles!
3. The idle rpm (and everything else) was checked and while the test, the rpm was 500 (a/c on and off)...just like yours! The history did not show anything!
4. I drive to save the mpg...cruise control on almost every road (except heavy traffic).
5. She now has 14,000 miles.
Thanks for you thoughts and if you have more, please let me know!
Any ideas? And ways to make improvement?
Thanks!
