the car: rsx base 5 speed

the problem: after about a 45 min drive. i come to a stop and notice my my rpm's are around 1500. it stays there and drops to idle and then rises up again and drops to idle. it does this for about 10 or 15 minutes when ever i come to a stop, and then for the rest of the drive is normal(5 or 10 min). i took it easier than normal but it drove fine otherwise.

what could be the problem?

 

possible faulty iacv.

 

agreed.

So only when the cars warmed up? It won't do it cold? Cause a vacuum leak should be constant

 

^^ agree.

 

tb sensor is gone need to replace tb happened to my GF rsx

 

can also be a vacuum leak

do you by any chance have a light weight flywheel??? They often cause fluctuating idle because the flywheel mass is too light for it to idle well at low RPM's (which is why most people with Kpro bump their idle up a bit)

 

Maybe you're really low on coolant? I know that most cars will have idle flux when the need to be topped off on coolant.

 

vacume leak or me map sensor needs to be cleaned.

 

Could just be the tps sensor

 

Basically, it could be a number of things. So start with the cheapest checks and go from there. You're bound to figure out what it is eventually.

 

It could be your MAP sensor (manifold absolute pressure) I had the same thing with my ep3 change the sensor hasnt happened sense. Sensor is only like 50$.

 

Remove the intake while its bouncing and plug the port to the IACV with your finger. If it stops bouncing, its something with the IACV. My K20 swap was doing the same thing a few weeks ago. Pulling the IACV apart and cleaning it solved the issue for me.

If that does not do anything, keep going down the list.

 

even cleaning a faulty iacv can still let the problem persist. sometimes the eletronics in them just go out.. just fyi

 

Mine did the same thing. You have to remove the IACV and give it a good cleaning. There is a how to on clubrsx.com