Weird SR Starting Issues... Please HELP!!!!! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

speedfiend · 01-14-2008, 09:40 PM

Alright guys I have searched but this is a very weird problem that I cant figure out. So lets start. When my is cold started (after sitting all night) it starts fine and runs fine. When I turn the car off and recrank it, it idles fine for about 10-15 secs then starts to spit and sputter for about another 10-15 secs then regains perfect idle and runs fine from there out. This problem only occurs when the car is turned off and turned back on within about an 1hr or 2. When it is cranked and spits and sputters I can unplug the mafs and it runs fine, then plug the mafs back in and it will run fine. I know it is not the mafs because I just replaced it tonight with a brand new one and it still does the same thing. It is not the coolant temp sensor because I have an hks fan controller and it is getting signal from the temp sensor and it is reading perfectly fine. I have a feeling it is my o2 sensor but it is fairly new as well. I dont think it is a wiring issue because it is not speratic at all. It spits and sputters everytime when the car has been ran and shut off and restarted within an hour or 2, but if it sitts for say 3hrs or more and is allowed to become completely cold then it starts right up and runs fine. Once again if I sit and let it idle for about 10-15secs while it spits and sputters, the rpms drop and my vacuum raises from about -19 psi up to -10 psi for the 10-15 secs then rpms and vacuum return to normal and runs fine afterwards. Sorry for such a long post and if you have any questions feel free to ask. Any help will be much appreciated. Thanx, Cameron

KiLLeR2001 · 01-15-2008, 01:33 PM

Could possibly be a wiring problem... Seems like your ECU thinks your car is always cold when you start it, so when its not cold and you start it, it'll act weird. But when it actually is cold, and you start it everything is ok. Check your ECU for codes. (This would be my guess, don't take my word for it though.)

speedfiend · 01-15-2008, 02:16 PM

Alright that was something I was considering. I will have my dad bring consult home this evening and see if there are any codes being thrown. I know its not the mafs because I put a new one on and it is still doing it plus my s-afc is reading afl just fine. Also it cant be my o2 cause my apexi tt is detecting voltage from my o2. It cant be my temp sensor cause my hks fan controller is reading from that and it is doing just fine as well. So the only other thing I cant think of is the ecu. Thanx for the input and any other ideas from anyone would be greatly appreciated. Cameron

01-14-2008, 09:40 PM	#1
speedfiend Zilvia FREAK! Join Date: Feb 2002 Location: Destin, Fl./Houston, Tx. Age: 40 Posts: 1,206 Trader Rating: (68) Feedback Score: 68 reviews	Weird SR Starting Issues... Please HELP!!!!! Alright guys I have searched but this is a very weird problem that I cant figure out. So lets start. When my is cold started (after sitting all night) it starts fine and runs fine. When I turn the car off and recrank it, it idles fine for about 10-15 secs then starts to spit and sputter for about another 10-15 secs then regains perfect idle and runs fine from there out. This problem only occurs when the car is turned off and turned back on within about an 1hr or 2. When it is cranked and spits and sputters I can unplug the mafs and it runs fine, then plug the mafs back in and it will run fine. I know it is not the mafs because I just replaced it tonight with a brand new one and it still does the same thing. It is not the coolant temp sensor because I have an hks fan controller and it is getting signal from the temp sensor and it is reading perfectly fine. I have a feeling it is my o2 sensor but it is fairly new as well. I dont think it is a wiring issue because it is not speratic at all. It spits and sputters everytime when the car has been ran and shut off and restarted within an hour or 2, but if it sitts for say 3hrs or more and is allowed to become completely cold then it starts right up and runs fine. Once again if I sit and let it idle for about 10-15secs while it spits and sputters, the rpms drop and my vacuum raises from about -19 psi up to -10 psi for the 10-15 secs then rpms and vacuum return to normal and runs fine afterwards. Sorry for such a long post and if you have any questions feel free to ask. Any help will be much appreciated. Thanx, Cameron

01-15-2008, 01:33 PM	#2
KiLLeR2001 Post Whore! Join Date: Jun 2007 Location: オーランドフロリダ Posts: 7,955 Trader Rating: (46) Feedback Score: 46 reviews	Could possibly be a wiring problem... Seems like your ECU thinks your car is always cold when you start it, so when its not cold and you start it, it'll act weird. But when it actually is cold, and you start it everything is ok. Check your ECU for codes. (This would be my guess, don't take my word for it though.) __________________

01-15-2008, 02:16 PM	#3
speedfiend Zilvia FREAK! Join Date: Feb 2002 Location: Destin, Fl./Houston, Tx. Age: 40 Posts: 1,206 Trader Rating: (68) Feedback Score: 68 reviews	Alright that was something I was considering. I will have my dad bring consult home this evening and see if there are any codes being thrown. I know its not the mafs because I put a new one on and it is still doing it plus my s-afc is reading afl just fine. Also it cant be my o2 cause my apexi tt is detecting voltage from my o2. It cant be my temp sensor cause my hks fan controller is reading from that and it is doing just fine as well. So the only other thing I cant think of is the ecu. Thanx for the input and any other ideas from anyone would be greatly appreciated. Cameron