Ok well my car is having a weird idle issue. It starts and idles fine. Once it gets to operating temp it will start to rev on it's own. It bounces from 200-1000 rpm. It also feels kinda sluggish. Like if I am driving in lets say 3rd hear at a constant speed with the rpm's at like 2500 it feels sluggish, then will feel like it pulls (has more power), then feels sluggish. It just keeps doing this.

What could this be? I'm not getting any CEL. I figured it might be some sort of sensor since it only happens when the car is up to operating temp. Could it be a bad coil? Would that make the idle bounce?

 

Well, did this just happen or did it happen after a modification? Sounds possibly like a vacuum leak at a gasket. The vehicle may be warming up, components are expanding and your getting an unmetered air leak somewhere causing an erratic idle. The sluggishness may be a result of the vehicle running lean. The only other thing that I can think of that may be causing a problem when it's fully warmed up is it's going into closed loop and trying to compensate while reading the O2 sensor(s). I'm not that familiar with honda particularly but you may check a factory service manual for a description of operation to see which sensors are coming online once the computer goes into closed loop as opposed to only the ones at cold start and checking those.

 

No no modifications. I did star/drive the car for like a month. Well after I started it up it started doing this. Wasn't doing it before, but after it sat it started.

I mean it has to be some sensor or something causing it. The ECU runs off of preset settings till warmed up, so when it gets warm and switches over that's when it is happening. I just can't figure out what would be doing it. A bad TPS?

Oh yeah for got this is on a D16Y8

 

Well, it's just one of those things that unless I was there to see what was going on it's pretty hard to say. You'd have to run tests on all suspect component until you stumble onto the problem. I've been working at dealerships for a few years now after graduating UTI and I always come across new and interesting problems. Keeps me on my toes. If possible, carry out tests for vacuum leaks, fuel pressure, check plugs-cap-rotor, engine timing, clean IAC valve, check for plugged PVC valve, air filter, plugged fuel filter and fuel flow. This should cover the basics and shouldn't take long. All this before you start condemning other components.

 

Plug your iacv and fitv holes in the inside of the tb when it's idling and warmed up. This should kill the car. If so you prolly don't have a vacuum leak. Then go ahead and plug only one and see if either hole alone fixes the situation, in which case it might be that sensor.

 

a good and easy way to check the sensor is with a dvom and find the output signal wire, test the voltage withe key on, engine off and do a slow sweep of the tps from full closed to full open. If there is any drop in voltage as you are opening it up, TPS is ****. Should range from roughly 0.8v to 4.8v. you will have to backprobe the connector instead of pulling it off the sensor. paper clip or needle should work..