Dirty aac valve? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Josho · 08-29-2011, 08:02 AM

My sr is doing the strangest thing. Last night I started her up and it was idleing up and down, trying to cut off until i gave it a little gas. When it warmed up a little it would stay running by itself but would jump to 1200 rpms and fall to abt 4-500 and jump back up. When I would rev it to about 4000 and let the rpms fall back down, it always would cut off. I noticed that, while revving it up, it wouldnt bog or anything, it revved as far as i wanted it to freely. My temporary fix was turning up the idle to about 1100rpms. I also Noticed that when the fuel pump was priming(255 fp) it didnt have a constant hmmmmmmmmmmm.. It is more like hmm hm hmmm m m hmmm m..
But now that I have the idle turned up everything seems to be fine, I can drive it around without it hesitating or trying to cut off.
I need to fix the problem regaurdless though. Just needed some opinions I guess. Does it sound more like the aac valve needs to be cleaned or a fuel pump replaced.. Or both? I just ordered a new 255 because mine sounds weak anyway.

FYI: I checked for boost leaks, cleaned and re-gapped plugs, and cleaned out my maf. This was all before I turned up the idle.

08-29-2011, 08:02 AM	#1
Josho Zilvia Junkie Join Date: Mar 2010 Location: AL Posts: 310 Trader Rating: (7) Feedback Score: 7 reviews	Dirty aac valve? My sr is doing the strangest thing. Last night I started her up and it was idleing up and down, trying to cut off until i gave it a little gas. When it warmed up a little it would stay running by itself but would jump to 1200 rpms and fall to abt 4-500 and jump back up. When I would rev it to about 4000 and let the rpms fall back down, it always would cut off. I noticed that, while revving it up, it wouldnt bog or anything, it revved as far as i wanted it to freely. My temporary fix was turning up the idle to about 1100rpms. I also Noticed that when the fuel pump was priming(255 fp) it didnt have a constant hmmmmmmmmmmm.. It is more like hmm hm hmmm m m hmmm m.. But now that I have the idle turned up everything seems to be fine, I can drive it around without it hesitating or trying to cut off. I need to fix the problem regaurdless though. Just needed some opinions I guess. Does it sound more like the aac valve needs to be cleaned or a fuel pump replaced.. Or both? I just ordered a new 255 because mine sounds weak anyway. FYI: I checked for boost leaks, cleaned and re-gapped plugs, and cleaned out my maf. This was all before I turned up the idle.