Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - rev limiter at 2000rpm (leans out), leans out under boost and rough idle

Keith_Bergen · 07-03-2010, 11:57 AM

First of all, the car has a s15 sr20det in it, hks bov, fmic, hks poncams, and splitfire coilpacks, plugs were replaced last year, and i'm running fresh premium fuel.

The problem i'm having is the car has a rough, stumbling idle, it completely leans out at 2000rpm and is difficult to get past. once past that, under boost it leans out to about 17-18, stutters and only boosts about 5psi. Driving down highway at consistant speed the engine runs perfect.

I have disconnected the o2 sensor to run open loop which changed nothing.

I checked maf signal - blue wire has 1.2V at idle, and 1.8V at 3000rpm under no load which is where it should be, pink (ground has ~0v), and black/white wire has 12V.

I can't find any vacuum leaks anywhere.

Cam's are timed

ignition timing is dead on 15 degrees btdc

Any help or idea's would be much appreciated as i've been trying to figure this out for weeks. Also, please no "Search" comments, as i've searched for days and can't find anything quite like this.

Thanks in advance for any advice.

07-03-2010, 11:57 AM	#1
Keith_Bergen Join Date: May 2008 Location: Manitoba Age: 31 Posts: 45 Trader Rating: (1)	rev limiter at 2000rpm (leans out), leans out under boost and rough idle First of all, the car has a s15 sr20det in it, hks bov, fmic, hks poncams, and splitfire coilpacks, plugs were replaced last year, and i'm running fresh premium fuel. The problem i'm having is the car has a rough, stumbling idle, it completely leans out at 2000rpm and is difficult to get past. once past that, under boost it leans out to about 17-18, stutters and only boosts about 5psi. Driving down highway at consistant speed the engine runs perfect. I have disconnected the o2 sensor to run open loop which changed nothing. I checked maf signal - blue wire has 1.2V at idle, and 1.8V at 3000rpm under no load which is where it should be, pink (ground has ~0v), and black/white wire has 12V. I can't find any vacuum leaks anywhere. Cam's are timed ignition timing is dead on 15 degrees btdc Any help or idea's would be much appreciated as i've been trying to figure this out for weeks. Also, please no "Search" comments, as i've searched for days and can't find anything quite like this. Thanks in advance for any advice.