Car runs better with no TPS!? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

nissantuner22 · 08-02-2004, 04:00 PM

My car is back to its old tricks. Extreme bucking under acceleration. Stomp the gas, RPM's stay locked at whatever RPM I'm at, than *maybe* all of a sudden rev up like crazy. I have no idea wtf is going on. So I disconnect the TPS, which is brand new, and the car runs and drives almost like normal. explain.

orion::S14 · 08-02-2004, 04:11 PM

Similar issue on my S13 (not nearly as severe, though), and it's a random thing. Happens every once and awhile, but never happens if the TPS is disconnected...

I've tried MAF cleaning, new plugs and wires, checked all the other likely culprits...to no avail.

I actually get better gas mileage with it unplugged, so I leave it that way.

Haven't tried a known-good MAF...and that's the next thing I'll do...as the MAF and TPS work together when the ECU is in closed loop.

- - - - -

Anyone know what the ECU defaults to with no TPS input...back to the "maps"...?

- Brian

sr240mike · 08-02-2004, 04:58 PM

With tps disconnected can you rev past 4500 rpms?

nissantuner22 · 08-02-2004, 05:03 PM

yep, took it to redline. was fine.

**mrmephistopheles** · 08-02-2004, 07:39 PM

perhaps it could be that you never properly set the 'NEW TPS'. They aren't just plug and play.

intrexin · 08-04-2004, 02:16 PM

Quote:

Originally Posted by mrmephistopheles

perhaps it could be that you never properly set the 'NEW TPS'. They aren't just plug and play.

whats the proper way to set them? Do you have any links or how to guides?

**mrmephistopheles** · 08-04-2004, 06:24 PM

Quote:

Originally Posted by intrexin

whats the proper way to set them? Do you have any links or how to guides?

Nissan Factory Service Manual for your model year.
Look around. There's online versions of FSMs all over. Or, you can do like alot of folks and buy one from Dyment.

No, I won't give you their number or anything more about them, nor will I give you any links to online FSMs. sorry.

-Kevin

twitchy · 08-03-2004, 12:00 AM

had the bucking problem

unplugged O2 sensor

runs great, awesome mileage too

nissantuner22 · 08-03-2004, 11:16 AM

interesting point on the, it not being set thing, but the car ran great for about a month. will try the O2 thing after I reconnect the TPS.

nightwalker · 08-04-2004, 05:41 PM

I bet you something (wire going to, or plug) on the TPS is fucked! Or you could have a bad ground. Dam nissans are notorious for those things.

andrave · 08-05-2004, 06:58 PM

very helpful.

08-02-2004, 04:00 PM	#1
nissantuner22 Zilvia FREAK! Join Date: Mar 2004 Location: Gainesville, Fl Age: 40 Posts: 1,056 Trader Rating: (-1) Feedback Score: -1 reviews	Car runs better with no TPS!? My car is back to its old tricks. Extreme bucking under acceleration. Stomp the gas, RPM's stay locked at whatever RPM I'm at, than maybe all of a sudden rev up like crazy. I have no idea wtf is going on. So I disconnect the TPS, which is brand new, and the car runs and drives almost like normal. explain. __________________ Current Project: Operation: N/A SR: 93 Silvia Q SR20DE Engine with go fast goodies. , "Common problems 240sx's suffer from are curbs, trees, ditches, and other immovable objects."thx247 "on the tounge... there is no guardrails."- citizen

08-02-2004, 04:58 PM	#3
sr240mike Zilvia FREAK! Join Date: Apr 2004 Location: California, Norcal biiaatch Posts: 1,185 Trader Rating: (0) Feedback Score: 0 reviews	With tps disconnected can you rev past 4500 rpms? __________________ TWO IN THE COOT, ONE IN THE POOT

08-02-2004, 05:03 PM	#4
nissantuner22 Zilvia FREAK! Join Date: Mar 2004 Location: Gainesville, Fl Age: 40 Posts: 1,056 Trader Rating: (-1) Feedback Score: -1 reviews	yep, took it to redline. was fine. __________________ Current Project: Operation: N/A SR: 93 Silvia Q SR20DE Engine with go fast goodies. , "Common problems 240sx's suffer from are curbs, trees, ditches, and other immovable objects."thx247 "on the tounge... there is no guardrails."- citizen

08-03-2004, 12:00 AM	#8
twitchy Zilvia FREAK! Join Date: Apr 2003 Location: Ontario Posts: 1,579 Trader Rating: (0) Feedback Score: 0 reviews	had the bucking problem unplugged O2 sensor runs great, awesome mileage too __________________ Who the hell needs a sig anyhow

08-03-2004, 11:16 AM	#9
nissantuner22 Zilvia FREAK! Join Date: Mar 2004 Location: Gainesville, Fl Age: 40 Posts: 1,056 Trader Rating: (-1) Feedback Score: -1 reviews	interesting point on the, it not being set thing, but the car ran great for about a month. will try the O2 thing after I reconnect the TPS. __________________ Current Project: Operation: N/A SR: 93 Silvia Q SR20DE Engine with go fast goodies. , "Common problems 240sx's suffer from are curbs, trees, ditches, and other immovable objects."thx247 "on the tounge... there is no guardrails."- citizen

08-02-2004, 04:11 PM	#2
orion::S14 Nissanaholic! Join Date: May 2003 Location: Orange Park, FL Posts: 1,666 Trader Rating: (0) Feedback Score: 0 reviews	Similar issue on my S13 (not nearly as severe, though), and it's a random thing. Happens every once and awhile, but never happens if the TPS is disconnected... I've tried MAF cleaning, new plugs and wires, checked all the other likely culprits...to no avail. I actually get better gas mileage with it unplugged, so I leave it that way. Haven't tried a known-good MAF...and that's the next thing I'll do...as the MAF and TPS work together when the ECU is in closed loop. - - - - - Anyone know what the ECU defaults to with no TPS input...back to the "maps"...? - Brian

08-02-2004, 07:39 PM	#5
mrmephistopheles Magnanimous Justice Distribution Service Join Date: Mar 2002 Location: BFE Age: 23 Posts: 14,372 Trader Rating: (9) Rides Gallery: mrmephistopheles Feedback Score: 9 reviews	perhaps it could be that you never properly set the 'NEW TPS'. They aren't just plug and play.

08-04-2004, 05:41 PM	#10
nightwalker Nissanaholic! Join Date: Mar 2003 Location: Bay area Age: 46 Posts: 2,146 Trader Rating: (0) Feedback Score: 0 reviews	I bet you something (wire going to, or plug) on the TPS is fucked! Or you could have a bad ground. Dam nissans are notorious for those things. __________________ In life, we often cast the line of hope fishing for the best possible opportunity. Sometimes with enough effort, the things we catch are nothing short of amazing.

08-05-2004, 06:58 PM	#11
andrave BANNED Join Date: Apr 2002 Location: Burton WV Posts: 2,350 Trader Rating: (0) Feedback Score: 0 reviews	very helpful.