| I've posted twice now in regards to idle issues with my Z. The engine runs like it has a slight vacuum leak. I boost leak tested and fixed 2 leaks. But since then it still idles a bit weird. Here are the first 2 posts:
First: La-Z-Link
Second: La-Z-Link I'll sum up the whole story right here though. I just swapped my engine out for a low mileage JDM engine. I just got it started up about 2 weeks or so ago. Everything seems good except for the idle. My idle is right around 700-800 which is about right. It doesn't jump or dip very much at all. The problem is I can hear the engine stumble here and there like it's pulling in air from somewhere. Like I mentioned above I boost leak tested it, first at 5 psi. Fixed 2 leaks, then it was recommended to try 7psi to see if I could yield any other leaks. No other leaks have been heard or found when boost testing. When I start the car I could hear what sounded like a leak at or around the IACV/IAA/Air Regulator. These being the suspect, and some members pointing me there as well, I tore it a part and everything looked good. I reassembled it, and have yet to reinstall it. I will do that tomorrow in the day light. I am doubting it will have any impact on the idle though. When I put a vacuum gauge on it, I believe it was around 17 with a little needle movement. I know it should be between 17-21 and the steadier the better. Although it is within the limits, I thought it seemed a bit low. Plus with the fluctuations and being on the low side, I am still thinking vacuum leak, and the fluctuations cause by cold valves and lifters still settling in. I power balance tested the engine, everything was fine there. I am thinking once I reinstall the IAA/IACV assembly I will compression test the engine, do another vacuum test on it when it's warm. I am thinking I will change out the spark plugs with another set that I have. I forgot to order new plugs when I did the 60k, and was hoping to get a few more miles out of the ones that I had. Probably a mistake, and could be the cause of a misfire here and there. A question I've had and have yet to find the answer to is, is there a place I could have a vacuum leak that would not show when pressurized during the boost leak test? It's looking like I've got a few more places to look. I've gotta pull codes as well. If I have a vacuum leak I should also be running lean, right? Any further insight will be greatly appreciated.
|
