Hey All,

So I have been having issues with the idle on my car and I thought I would clean my IACV our, per the instructions that can be found on this site. I cleaned it out and during the process, I kind of broke the part on the IACV that connects to the harness connector. I did not break it completely off, but I think I might have broke one of the two wire connects on the connector.

So, after getting everything put back together, I started the car and it barely idles, fluctuates like crazy and I am getting a TON of smoke coming out of the tailpipe now. I also noticed I am getting a check engine light now. I have not pulled the code, yet. I will in a few.

My question is, will a faulty IACV cause the engine to run like this? Not able to idle, stalling and a ton of smoke coming out the tailpipe? I am thinking this is the only possability because the only things I did were clean the IACV and do a compression test. My compression came out 200/195/195/192 so I know the rings are good.

Anyways, please let me know ASAP. If it is a bad IACV, any recommendations on where to source a used one to replace it? The engine is a SOHC ZC. I am assuming its the same IACV as the D16a6?

Thanks!
-Jason

 

Okay, so I found a couple problems that I somehow missed. First off, the TPS sensor was unplugged... oops. Second, one of the thin, black hoses leading to the MAP sensor was disconnected. I plugged these back in and now the car fires right up, idles and there is no more smoke from the exhaust pipe. I checked the ECU and found the following codes before and after these two fixes. I am seeing:

Code:

1 - Oxygen Content
5 - Manifold Absolute Pressure
7 - Throttle Angle

The weird thing to me is the check engine light is now off, but I am throwing the same codes after the fixes as before. I did pull the 15a fuse for the ECU in the engine bay, but is there something else that I need to do to reset or make the codes go away?

The car is running rich and sometimes the idle will sit at about 800rpms and then all of a sudden it will drop down to about 200rpms and come close to stalling out. I have been assuming this is a result of how rich it is running.

Can anyone tell me what would cause the number 1 and 7 ECU codes? The MAP I can figure out, but the others I have dealt with before.

Back to the compression test...

I ran this last night just because I had the gauge and had a few minutes to test it out. The test was ran with a cold motor, with the 15a fuse unplugged and with the injectors disconnected. We installed the gauge, floored the gas and cranked it over 5 times for each reading.

The longblock is totally stock internally, there has been no increase in compression via a thinner headgasket or shaved head. From what I have read over the years, 195-200psi seems like a good reading for a lower compression engine (9.0:1 ratio) with a decent amount of mileage on it.

I do have the basic bolt on's, plus a high boost JRSC setup, so I mainly ran the compression test to ensure the rings were still on the healthy side. I have a DPR prepped head that I plan on swapping on soon, so this should give me a bit more compression and power.

Thanks again for the help so far and please let me know about the code 1 and code 7. I need to figure out how to diagnose and repair these.

-J

 

Code 1 is an O2 sensor code, probably triggered by the fact you started the car without the MAP sensor connected.

Code 7 is the TPS sensor (throttle angle/position sensor). Once again probably triggered when you started the car without the TPS plugged in.

Are you sure you are resetting the ECU correctly?
You say you reset the battery by removing a 15amp fuse? In my crx to reset the battery properly, I remove the 10amp fuse under the hood labeled: "Hazard" or you could just remove the neg battery cable.

 

It sounds like I am trying to reset the ECU the wrong way. I'll try your way and see what happens.

 

To first post: IACV will cause jumpy idle and most if not all of the other symptoms.
To reset ECU, always pull neg on battery, its easiest and most sure-fire way I know of.