Martinez8o5

whats up guys, new here, i have an idle problem with my 97 civic dx. it starts up just fine, and idles a little high and after a few seconds it starts to idle up and down not sure at about how many rpm's but it seems to be at around 1500-2000, i had this same problem on my 93 hatchback and resolved it by cleaning the FITV, replacing the IACV and TPS,it resolved that issue, i tried the same thing on the 97 except the FITV because it doesnt have one, i cleaned the throttle body thoroughly replaced the PCV valve changed out the coolant (i read somewhere that it could be air in the coolant system causing that) but nothing has worked, before it would just rev high and a check engine light came on apparently the tps i bought from autozone was bad so i changed it and then it started surging. i dont know what to do anymore, i dont think i have a vacuum leak. any help will be greatly appreciated, thanks in advance

ezone

Adjust the TPS so its output voltage is 0.49v with the throttle closed.

See if that makes any difference.

Also check for vacuum leaks from replacing the part, pulling the throttle body off, etc.

Martinez8o5

is that just turning it? if so ive tried that and all it does is go back to a high idle
TBH id rather have it surging rather than staying high
i did have two vacuum leaks but discovered them in the process of cleaning the TB

mikey1

i think you do........

ezone

No, that's randomly twisting it without knowing what you are doing.

The computer relies on an accurate input from that sensor.
Some random starting point is in no way accurate.


No. Surging is what the engine is supposed to do when you have a problem causing it to idle far too high.

Figure out why it idles too high, fix it, and your surging will magically be gone.

I think you still have leaks.
Internal or external, you still have leaks.
IAC stuck open?

Martinez8o5

ok so i take it that its something that i cant fix myself with basic tools? should i take it to a shop or do you have any suggestions on what else i can do to find leaks, internal and external?
I dont think the IAC is stuck open i recently replaced it with a new one

mikey1

i can not tell what your skills are, or if u are capable of fixing it,

if you dont think the IAC is the problem then it sounds like you have an intake air leak,

are you are capable of finding that leak and repairing it? who am i to say?

Martinez8o5

would a video help more? to see exactly what it sounds like?

ezone

What mikey said.

Tools are but a small part of solving a problem.




The engine needs a lot of unregulated air to run faster than it should at idle.
How is it getting that air?


I'd say first remove the breather tube and locate the small ports in the side of the throttle body opening,
Similar to these



plug the ports with your fingers and see if the RPM comes down to normal.
If it comes down to normal or stalls the engine, then see why the passage is open too much.
If it does not come down, then look elsewhere for vacuum leaks.



We know what surging sounds like, but go for it.

You need to listen for the sucking sound of vacuum leaks though.

mikey1

pcv hose leaking, or disconnected?

Wankenstein

Smoke up Johnny and do a cigar leak test by disconnecting the vacuum hose from the brake master cylinder and doing this (engine not running):