Idle RPM's ? - Honda Prelude Forum

Dozer · 10-15-2002, 08:38 AM

When I cut my car on and it has been sitting for awhile the engine will rev at about 1300 RPMs and then a couple of minutes later it will drop back down to about 400-500 rpms. When I'm sitting at stop lights some times I will notice that my rpms are at 200- 300 but it doesnt feel like it is going to stall. The engine feels fine. My question is 200 rpms way too low to idle at. Again it doesnt feel like it going to stall, 200 just seems low. I want to get pulleys soon but I heard they lower your idle rpms alittle and I want to cause problems. I have a 97 base with I/E and 60,000 miles.

fmshaw1971 · 10-15-2002, 09:09 AM

Damn, 200 rpms? That is abnormal. Do you have an intake? If so, check to make sure all the vacuum hoses are tight. You may also want to change your plugs if you haven't done it yet.

okieraver · 10-15-2002, 09:13 AM

helms manual says its supposed to be at 700 +-50
your supposed to get your idle adjusted periodically, thats normal maintenance work. i doubt its idling at 200 tho, i would assume your engine would stall at that speed (i think your guages could be off)

Niffum · 10-15-2002, 11:49 AM

Make sure you didn't read the tach wrong...
The tach goes from 0 -> 500 -> 600.. and increments of 100 thereafter...

allaw · 10-15-2002, 01:57 PM

i guess dozer must have misread the tach. I did it to until i read niffum's post. While at 700 it is halfway from 0-1000.

geerboy69 · 10-15-2002, 07:10 PM

yea dude at 200 you should stall, listen to niffum

mine actually rattles the car when it drops to idle speed, anyone think i should get my adjusted?
i mean nomally you can't feel engine vibrations but when mine idles after warm up i can feel mine, nothing to bad but i can feel it

Randy0002 · 10-15-2002, 08:04 PM

At 200 rpm's you'd hear the car gasping for life...thats really low. My stock idle was around 700 - 750. When I got my pulleys it dropped it to 500 and has been there since. If you don't have any mods you may want to have your idle reset.

crashandburn · 10-15-2002, 09:34 PM

Pulleys won't lower the RPM of your engine, they'll lower the RPM of the accessories they're attached to (PS pump, alternator) and at idle, that can make your alternator turn too slow to generate its normal power. That's what people are talking about with the pulleys.

I wouldn't worry about the 200-300 RPM. Stock tach is not that accurate, particularly at the extremes (low and high end). If you maintain your car correctly (changing filters, fluids, etc) and the idle feels smooth, then you probably don't have any problems and its just your tach not reading exactly right.

RJs99TypeSH · 10-16-2002, 12:46 AM

First off, the 1500 rpm start is normal. The motor will induce different idling characteristics to ensure quick warmups and rapid oil dispersion.

As far as the 200/300 rpm idle; everyone here has said good points, but one thing that is really important is to feel it out. If, as you said, it feels like it's idling fine; there is no hesitation when leaving the line; it doesn't die easily or stutter or gasp; then you are probably fine. You should also watch fuel consumption, as well as any output from the tailpipe. If anything seems abnormal, you should look into it. Just be observant.

Optimally it should be at 650-750, and, if you were reading the tach as being statically incremented (to come to your 2-300 rpm conclusion) your car probably is idling around 700 rpms.

I hope this helps, good luck!

R
J

Dozer · 10-16-2002, 10:14 AM

Thanks for the help guys. I think I was just reading it wrong. I didnt have my car to go out and look at when I made the first post. I think everything is normal.