RotaryPWR

When I start the car, the rpm go to 2000, then down to about 1100, then up to 1500, then down to 1000, then up to 1200 ish rpm (exact rpm numbers vary depending on outside temperature). It then holds this rpm til it warms up, then drops to a steady 750 rpm idle.

I was just wondering if this sorta thing is normal (some sort of check sequence) or if it is something i should look into (my guess is it is a problem haha).

I have looked at threads about idle issues, so I know what to look for. I just don't know if it's a huge problem or not. So please don't flame me

Other symptoms that I wonder about are that the rpm go up 100-200 rpm from idle when i release the brake pedal, and the rpm go down 200-300 from idle when i turn the steering wheel by at least 45 degrees or so. Is this normal or should i be trying to get rid of this?

I cleaned out my IACV which helped reduce the severity and occurance of an idle bounce every couple of minutes, but i think it's still present.

Finally, do manual d16y8's have an FITV? Hayne's says they don't, and from what i've noticed they don't, but i haven't checked thoroughly yet..

Thanks in advance!!

92ehatch

your y8 does not have an FITV.

usually this would be caused by the IACV or a possible vacuum leak.

since you cleaned your IACV i would look for a vacuum leak, or faulty pcv valve (or possibly a collapsed pcv valve hose)

RotaryPWR

what is the recommended way to check for vacuum leaks? i've heard of both visual/feel checks, and also spraying lines, seals, and gaskets with carb cleaner and monitoring for a change in rpm.

rick_rabies

i spray starter fluid on the hoses to find a leak.
but if you cleaned your iacv..and it helped..but the problem is still there...try a new iacv annnnnd bleed the coolant...try that..but iacv are expensive

andoxviii

iTrader: (1)

It is normal for your engine to idle around 1500-2000 rpm when it is cold. This is so it warms up quicker to regular operating temperatures. If it is going down and then up again, there is probably an issue.

Do you have a CEL?

92ehatch

it is normal for it to idle higher when cold, it is not normal for it to bounce around when cold

rick_rabies

its called cold start. i think obd2b d16s had it. its in the intake manifold.

RotaryPWR

haha oh gosh!! no, i know that the car idles at 1500-2000 when cold and then drops. it's more the 3 bounces that occur at startup that i wonder about. and nope, no CEL.

well i think the iacv is fine. i may just believe that cleaning it helped just so that i can feel like what i did was helpful it looked like it was in pretty good shape when i pulled it, it just had a slim layer of dirt on the filter, the bolts looked brand new, and all that i could see of the insides of the valve looked good. the only iffy thing was that the plate and screws holding the coolant tubes on the iacv were rusty and i couldnt unscrew them.

i also bled the coolant not long ago (removed rad cap and ran engine for 15 mins or so) and the coolant didnt boil at all. i didnt mess around with the bleed screw at all..so i hope that was enough?

so what seems to be left is a vacuum leak check, pcv check, and a tb check/clean. 1998 d16y8's don't have EGR valves, correct?

RotaryPWR

whats called cold start, the bouncing?

rick_rabies

no. the higher rpm idle when its cold until it warms up.
the bouncing is something wrong.
if i was you id get a new iacv and put it on and bleed the coolant.

RotaryPWR

please see my post above..i dont believe its my iacv, and i bled (hopefully properly) not long ago. if my other checks dont give me any leads, then i will replace the iacv like u suggest.