RB20 Idle hunting - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

kungfujoe · 04-16-2013, 07:33 PM

Ok, here we go.

I've been chasing this damned idle problem since I bought my car. I've tried to describe it on several forums as well, which never seems to go very well, so, instead, I made a video of my car idling instead. It's only about a minute long, so if you think you can help, by all means:
Note: My Tach is still a 4Cyl, so math might be involved. Just know I'm shooting for a reading of 1.3K, which means my engine is damn near 900 RPM. Also, this is just after starting my car. Unless otherwise noted, I do not touch any of the pedals.
My YouTube Video
(inb4 "ghetto boost gauge mount"...I know...)

Anyway, I think the video very accurately displays what happens. I've annotated it to show what I'm doing, but basically, I start the car at a dead stop and it does it's Idle hunting thing.

Things I've tried:
Hunted for vacuum leaks, and fixed them when found.
Hunted for boost leaks
Power balance tested the engine
Changed my spark plugs
Cleaned my MAF
Disassembled, cleaned, and set my TPS

Things I think could still be wrong:
Needs a 255 FP
O2 sensor plug is slightly melted...so replace the whole thing I guess
New MAF
Check for more vacuum leaks
(doubtful) I could stand to upgrade to a 3" exhaust

Any other guidance is appreciated.

GalmTeam · 04-17-2013, 10:16 AM

have you tried cleaning the iacv;
Some people have success with that when their car would start hunting at idle

http://i172.photobucket.com/albums/w.../IMG_19051.jpg

aga · 05-01-2013, 01:15 PM

how do you clean it? carb cleaner?

04-16-2013, 07:33 PM	#1
kungfujoe Join Date: Aug 2012 Location: Tacoma, WA Age: 32 Posts: 2 Trader Rating: (0) Feedback Score: 0 reviews	RB20 Idle hunting Ok, here we go. I've been chasing this damned idle problem since I bought my car. I've tried to describe it on several forums as well, which never seems to go very well, so, instead, I made a video of my car idling instead. It's only about a minute long, so if you think you can help, by all means: Note: My Tach is still a 4Cyl, so math might be involved. Just know I'm shooting for a reading of 1.3K, which means my engine is damn near 900 RPM. Also, this is just after starting my car. Unless otherwise noted, I do not touch any of the pedals. My YouTube Video (inb4 "ghetto boost gauge mount"...I know...) Anyway, I think the video very accurately displays what happens. I've annotated it to show what I'm doing, but basically, I start the car at a dead stop and it does it's Idle hunting thing. Things I've tried: Hunted for vacuum leaks, and fixed them when found. Hunted for boost leaks Power balance tested the engine Changed my spark plugs Cleaned my MAF Disassembled, cleaned, and set my TPS Things I think could still be wrong: Needs a 255 FP O2 sensor plug is slightly melted...so replace the whole thing I guess New MAF Check for more vacuum leaks (doubtful) I could stand to upgrade to a 3" exhaust Any other guidance is appreciated.

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04-17-2013, 10:16 AM	#2
GalmTeam Join Date: Apr 2013 Location: Canada Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	have you tried cleaning the iacv; Some people have success with that when their car would start hunting at idle http://i172.photobucket.com/albums/w.../IMG_19051.jpg

05-01-2013, 01:15 PM	#3
aga Zilvia Junkie Join Date: Mar 2013 Location: Athens, Greece Age: 43 Posts: 580 Trader Rating: (0) Feedback Score: 0 reviews	how do you clean it? carb cleaner?