RPM goes up down up

[city_bug]

Hello everyone, I need your advise. I'm driving a '97 Honda City, the problem is with the rpm. When I start my engine, the rpm revs to about 1500, then after running for about 20-30 seconds it goes down to 800 when I'm not accelerating, which I think is pretty much normal (or is it?).

Then after driving for about 10 mins. or so, the rpm again revs up to 1500 when on standby. But the weird thing is, when I turn the engine off then on again, the rpm will flicker up and down for about 5 seconds, and then rests at 800.

This happens every time I take my car out. The "check engine light" is off, no warning/alarm lights is on. What could be the cause of this problem? Any help would be very much appreciated. Thanks.

[weisshorn]

Baka kailangan ng engine tune up yang ride mo. Kumusta naman ang condition ng MAF sensor? (kung meron, sorry di ko familiar ano ang makina nitong car).

[skyglider]

maybe your iacv is dirty. palinis mo lang sir...

[dongsky07]

Hi city_bug, ok na ba car mo? I think I'm getting the same issue with the corolla GLi. Anong pinaayos mo? I already got some tips to clean out the sensors. Hope you can help me out.

[isa1023]

Baka kailangan ng engine tune up yang ride mo. Kumusta naman ang condition ng MAF sensor? (kung meron, sorry di ko familiar ano ang makina nitong car).

AFAIK, wala pong MAF sensor ang makina na ito.

maybe your iacv is dirty. palinis mo lang sir...

+10

Hi city_bug, ok na ba car mo? I think I'm getting the same issue with the corolla GLi. Anong pinaayos mo? I already got some tips to clean out the sensors. Hope you can help me out.

Honda ECUs are really programmed to rev 1500 rpm from cold starts. Some Nissans on 1100 rpm. Not sure on Toyotas. But cleaning dirty MAF sensors and throttle body/iacv could be a sure thing.

[dongsky07]

Thanks isa1023,

Any recommended shop for the cleaning? My mechanic suggested na dalhin ko na lang daw sa evangelista so readily available ang parts just in case. How much kaya ang charge for the regular cleaning?