RPMs drop too slow, what causes that?

mymaxi41691 · 11-02-2008, 10:06 AM

After getting my crank positioning sensor replaced a few months ago, i noticed that when reving in neutral my rpms drop too slow. Car is a 2000 5 speed with 65k miles on it. If you guys don't get what im saying i can post a video later.

*Scottwax* · 11-02-2008, 08:26 PM

No idea but stop reving your engine in neutral. It isn't good to rev an unloaded engine.

mymaxi41691 · 11-02-2008, 10:39 PM

wait, what? its not good to rev in neutral? since when

*Scottwax* · 11-03-2008, 05:10 PM

Quote:

Originally Posted by mymaxi41691

wait, what? its not good to rev in neutral? since when

The engine isn't under load and and basically revs up too quickly. Most newer engines actually have a lower rev limiter when the car is in neutral because of this. If you rev it to 2000-2500 or so, no biggie but if you are nailing the throttle and revving past 4000-5000 rpm isn't good for the engine if it is unloaded (not in gear and driving the wheels). A quick rev and dumping the clutch is okay at the strip. I see people start their cars, and rev the crap out of them right away in neutral and that puts a lot of unecessary stress on the engine.

http://wiki.answers.com/Q/Is_revving...ine_bad_for_it

Anyway, what are you revving the engine to and what is the rpm dropping to? A video might help.

mymaxi41691 · 11-03-2008, 08:38 PM

oh i see. Well i dont ever rev my car high for two reasons, one, gas aint cheap, two.. well i just dont need too. But im reving to like 3 and the rpms drop slow. Ill post a vid tomorrow.

maxgen5 · 11-18-2008, 12:38 PM

The stealership can reset your fuel mapping and your idle to the normal 685RPM or so. I did mine. It was erratic from 400 up to 900 RPM and all he did was reset the fuel mappings to default and the idle to default. Idles smooth and consistent now. It would have been 15 min. worth of labor, but it's good to be childhood friends with a Nissan certified mechanic.