[CRX_tuner]

heres the scenario. when i first start up it idles around 1700 rpm, which i know is way too high. after about ten min of driving it dropes to about 750 and oscillates about 300 rpm. whats the deal? iac valve? :nuts

btw:

88 dx
d15b2

 

[hobie237]

it idles high at first then comes down, like any other car...

if its going up and down check: vaccum, then iacv

if its staying high: pcv valve

 

[Roro]

My Si does all of those. the idle will go from 900RPMs to 1900RPMs constantly droppping then rising then dropping the rising it is SOOOOO annoying I have no idea how to fix it. And sometimes when I am coming to a stop when I put it in neutral sometimes the RPMs will rise to 3kRPMs and stay there then if I blip the throttle it goes back to fluxuating again. Also I noticed sometimes if I am in gear and I let off the throttle, sometimes it is as if the throttle is stuck open and will be going on its own. It will not decelerate. Sometimes it does this sometimes it does not. I think it is time for a new motor. My A6 has 199xxx miles on it now. No smoke, no trans grinds, nothing. The motor is actually in good shape.....

 

[hobie237]

then its not time for a new motor, look at the throttle system... if its sticking its probly the spring that closes it... or something with the cable... dont try a thousand dollar fix to a five dollar problem

as for the idle, do what i said before

 

[Roro]

its proabably the TPS sensor thats what it is on my Si at least thats what it was on my friends FC RX7 and my friends Lude

 

[Kami-CRX]

I have the same basic problem. It's not the TPS, it's not the throttle sytem, it's not a vacuum leak, it's not air in the coolant, and I'm pretty sure it's not the IACV as I replaced it, but I replaced it with an IACV I got off of eBay so who knows if the thing was actually working properly...

 

[90rexzc]

Mine (D15w/mpfi) did the same exact thing. it would idle at about 2500 until it was warm then would bounce from 1000 to 2000. It wasnt the IACV, it wasnt air in the coolant, it wasnt a vaccum leak so heres what i did... this isnt the perfect fix but it worked for me. Leave the car running and take your intake tube off and look inside the throttle body. there should be a hole on the inner wall of the throttle body, towards the firewall. plug it with your finger. If it idles normally go buy a rubber plug at the hardware store and plug that hole. I know, I know your not really "fixing" the problem, but mine has been idling just fine for the past 2 months. Actually it would bounce a little once in a while until i got a new alternator. I have no idea why. But im not embarrassed anymore when pretty girls pull up next to me at stoplights.

 

[Pearly00bseries]

if you car is OBD1 you have a Fitv. tighten that up. for the 00si, no idea having the same problems.. im seeing if its my iacv

 

[Roro]

its TPS - I replaced it w one I found on Ebay for $9.00 and it worked like a charm. Trust me, its TPS - I did it and it worked. O and btw, I swapped the motor anyways after that I went w a VTEC motor.