change in idle speed

My 95 SL-2, 5speed has 140000 miles on it and when coasting foward or backward when I reach a certain speed about 10mph the idle goes up to about 2000rpm and stays that way until about a second after the vehicle stops again. What is casuing this and how do I fix it?

i have seen this "coasting idle" before, when i saw it happen on my saturn it was always right after my ex drove, she did many of the things you should not do to manual transmission - ride the clutch(you should keep your foot off the clutch when not shifting) , decel with clutch pressed in(downshift or shift to neutral), and hold the clutch in at a stop(keep it in neutral until you are ready to move). my theory is the computer can detect these abuses of the clutch, and increases the idle to prevent damage to the driveline, by whatever cause, i could be wrong, but after everytime she drove, i could reset the PCM and the engine idled properly. so in short, if you do any of the above, please adjust your habits(many people don't even know the above is abuse)

some cars, maybe more, do respond differently to the persons driving habits. i could tell in my car that one day i drive it easy, the next i drive it hard and it feels like it lost power. the next day i drive it hard again and it feels great. next day i drive it easy and seems to have more power. once again drive it easy and power seems to have kicked down.

i figured i had a problem, but it happened at such intervals there was no way it could be so random. i was very in touch with my car and knew every little thing about it that others could not detect. cant get that feeling with my daily driver.


but anyways to your problem, you could have a hanging throttle, bad iac, or bad tps. first thing to try, when this problem happens, hit the throttle and see the response afterwards. next clean the throttle body. i think a bad map sensor can even cause this issue. but also take sierrap615 advice if you happen to do things he said not to. your engine and clutch will thank you too

I never ride the clutch. A person couldn't get 141000 miles out of the original clutch by riding it.

I decel with the brakes until the engine reaches normal idle speed and then depress the clutch pedal.

How does sitting at a stop with the clutch pedal depressed abuse the clutch?


Would the VSS cause the idle surge?