Car won't go in decel - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

di-devol · 05-05-2012, 05:40 PM

Goes runs rich when off the throttle. Car will not go into "decel" mode where the car should cut fuel completely, inseatd goes rich about 10-12 afr.

Vacuum is 19-20 at idle

s13 SR20det
Tomei 256's
9:1 cp
JWT Tune
GT2871r
Car idles at 14.7
Boost at 11.5
cruise at 14-15, no hesitation while driving, car runs perfect.
TPS is at .45, I've tried higher and lower, no change.
No codes
No boost leak, no vacuum leaks\
02 sensor is good
maf is good

Car was going into decel fine till a couple days ago.

Derp?

KiLLeR2001 · 05-05-2012, 08:34 PM

Check throttle plate and throttle cable make sure its not getting stuck.

di-devol · 05-05-2012, 08:37 PM

Lol, I'll look.

di-devol · 05-05-2012, 10:03 PM

Plate and linkage is fine.

KiLLeR2001 · 05-05-2012, 10:15 PM

Did you test the TPS thoroughly? What is the voltage at full open and full close?

di-devol · 05-05-2012, 10:25 PM

Closed .45, open is 4.10. I'be tried down to .40 in .1v increments. Also went up to .5 just to check. I've only found one thread on here where someone had the same problem, tps was their issue.

KiLLeR2001 · 05-05-2012, 11:33 PM

0.45V to 4.1V is normal. Post pictures of your engine bay. Do you remember doing anything before this happened? Maybe you hit a bump or messed around with a wire. Try to think.

cotbu · 05-06-2012, 08:17 AM

Your tps voltages are good, but you may not be getting the tps close signal. I would check with, consult, nistune or whatever tuning software you use to verify that you are getting the tps closed signal. Then adjust the tps, to that voltage. Or try pulling the pedal up with your foot instead of just letting off, it could be getting stuck befor tps close happens.

cotbu · 05-06-2012, 03:09 PM

Stop making excuses, not to dyno your car!

di-devol · 05-06-2012, 06:03 PM

Lol, I'm not making excuses. Traced the tps wire to the ecu, found a short. All better.

05-05-2012, 05:40 PM	#1
di-devol Zilvia FREAK! Join Date: Jun 2010 Location: Woodinville Age: 43 Posts: 1,412 Trader Rating: (5) Feedback Score: 5 reviews	Car won't go in decel Goes runs rich when off the throttle. Car will not go into "decel" mode where the car should cut fuel completely, inseatd goes rich about 10-12 afr. Vacuum is 19-20 at idle s13 SR20det Tomei 256's 9:1 cp JWT Tune GT2871r Car idles at 14.7 Boost at 11.5 cruise at 14-15, no hesitation while driving, car runs perfect. TPS is at .45, I've tried higher and lower, no change. No codes No boost leak, no vacuum leaks\ 02 sensor is good maf is good Car was going into decel fine till a couple days ago. Derp?

05-05-2012, 08:34 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	Check throttle plate and throttle cable make sure its not getting stuck. __________________

05-05-2012, 10:15 PM	#5
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	Did you test the TPS thoroughly? What is the voltage at full open and full close? __________________

05-05-2012, 11:33 PM	#7
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	0.45V to 4.1V is normal. Post pictures of your engine bay. Do you remember doing anything before this happened? Maybe you hit a bump or messed around with a wire. Try to think. __________________

05-06-2012, 08:17 AM	#8
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 50 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	Your tps voltages are good, but you may not be getting the tps close signal. I would check with, consult, nistune or whatever tuning software you use to verify that you are getting the tps closed signal. Then adjust the tps, to that voltage. Or try pulling the pedal up with your foot instead of just letting off, it could be getting stuck befor tps close happens. __________________ LoverTechnologies "Half Broken Things!"

05-05-2012, 08:37 PM	#3
di-devol Zilvia FREAK! Join Date: Jun 2010 Location: Woodinville Age: 43 Posts: 1,412 Trader Rating: (5) Feedback Score: 5 reviews	Lol, I'll look.

05-05-2012, 10:03 PM	#4
di-devol Zilvia FREAK! Join Date: Jun 2010 Location: Woodinville Age: 43 Posts: 1,412 Trader Rating: (5) Feedback Score: 5 reviews	Plate and linkage is fine.

05-05-2012, 10:25 PM	#6
di-devol Zilvia FREAK! Join Date: Jun 2010 Location: Woodinville Age: 43 Posts: 1,412 Trader Rating: (5) Feedback Score: 5 reviews	Closed .45, open is 4.10. I'be tried down to .40 in .1v increments. Also went up to .5 just to check. I've only found one thread on here where someone had the same problem, tps was their issue.

05-06-2012, 03:09 PM	#9
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 50 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	Stop making excuses, not to dyno your car! __________________ LoverTechnologies "Half Broken Things!"

05-06-2012, 06:03 PM	#10
di-devol Zilvia FREAK! Join Date: Jun 2010 Location: Woodinville Age: 43 Posts: 1,412 Trader Rating: (5) Feedback Score: 5 reviews	Lol, I'm not making excuses. Traced the tps wire to the ecu, found a short. All better.