help with s14 problem fast (tracking on sunday) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

psychedelicbeats · 12-01-2004, 10:42 PM

help i shitted my pants driving home (s14). i am breaking in my manual tranny (s13) from swap. before this problem, everything was ok. ran 100% good. nothing is wired up at the moment, but the ghetto rig to start up the car. now (as of dec 1, 2004), in any gear.... if the car is being pushed WOT from under 2000rpms, it will go jolting/lurching like crazy bouncing up and down on the revs. it feels like it's hitting the rev limiter and goes crazy if you know what i mean, and more violently like a stall. i tried driving it with a slow acceleration and it is good. after 2000rpms, with WOT it will run fine, but anything below it will cause the car to lurch/jolt/hesitate violently. i'm not sure if this will be tranny and/or electrical related(headed more to electrical related because the tranny feels good), but i am headed to the track on sunday and i need help fast. any help appreciated thanks. my aim sn is psychedelicbeats

psychedelicbeats · 12-02-2004, 12:32 AM

tps related?

orion::S14 · 12-02-2004, 08:46 AM

Sounds like you left the wrong TPS plug connected, or something (Or left the TPS disconnected all together).

Auto cars have 2 TPS plugs: One for the auto trans, the other for the ECU. The auto trans one is a kickdown switch...so it reads nothing or +4v (IIRC).

Check those.

- Brian

psychedelicbeats · 12-02-2004, 12:46 PM

i've double checked and it's connected correctly. haven't used the multimeter yet but will definitely soon. this is definitely an electrical problem. again, the car will not respond to WOT. ecu calculations are not going in right... could this involve speed sensor problem?

95Blue240sx · 12-02-2004, 01:18 PM

check you mafs???

psychedelicbeats · 12-02-2004, 03:38 PM

of course. maf is not an issue. i checked the independance of wot on the tps and it reads around 1.02ohm. is this correct? full closed is .5ohm, partially open is around 3.16ohm

96twofourty · 12-02-2004, 06:36 PM

Quote:

Originally Posted by psychedelicbeats

of course. maf is not an issue. i checked the independance of wot on the tps and it reads around 1.02ohm. is this correct? full closed is .5ohm, partially open is around 3.16ohm

check the voltage, not resistance

psychedelicbeats · 12-02-2004, 09:01 PM

during this diagnosis, i figured i would goto a shop (aerodyne) and get some more info. they told me that the ecu is throwing mixed codes each time... almost every code, and that it is a major electrical issue. would the tps actually have caused this problem to start off? i'm gonna use a 91' ecu and tps tomorrow and see what's going on. any help appreciated here.

to all: symtom: ecu going crazy problem: ?

bad ecu? would a bad ecu even start the car?

orion::S14 · 12-02-2004, 09:26 PM

'91 ECU has a different plug, and is NOT compatible at all with an S14.

You need to try another S14 ECU. Or just make sure the plug is tight on yours...I've heard of crazy problem when the connector isn't tight, or not on straight.

- Brian

psychedelicbeats · 12-03-2004, 12:33 AM

could this involve fuel pump issues? what are the symtoms of a bad fuel pump?

orion::S14 · 12-03-2004, 08:25 AM

Bad fuel pump would not run well at WOT...

??? - Brian

yellow_jacket · 12-03-2004, 09:06 AM

If this is throwing all sorts of codes, then that is usually indicative of a wiring problem. The most common being a bad ground. If you recently replaced the ecu or wiring harness, I would remove the plugs and look at the pins. If there is any dielectral grease, remove it. Look for any discoloration of the male and female pins. Look at the females and make sure they are not opened up. Basically, make sure you have great connections. Then start looking at your grounds.

psychedelicbeats · 12-03-2004, 04:15 PM

this is getting way closer to fuel pump issue but i donno yet. i haven't felt a bad fuel pump before. the problem that i have is like 3000-0-3000-0-3000-0-etc at WOT. it feels like an electrical issue(goes up and down fast), but again i've never rode on a car with a bad fuel pump. well back to getting it fixed. any help appreciated here.

edit: car STALLS now when trying to accelerate off on gear 1. the car goes bazerk and then it's basically shut off.

psychedelicbeats · 12-04-2004, 12:13 AM

thanks for the help so far, but bump bump bump it up for more help.

this is indeed an electrical problem. it lies at the intake manifold side where the egr valve is located. there's a couple of sensors inbetween the manifold there. whenever the key is turned from 1 to 2, it will make a buzzing, static-y sound. could someone elaborate with me and help me figure out what is going on.

psychedelicbeats · 12-04-2004, 10:35 PM

thanks for all of hte help everyone, but i dont think i'm gonna hit the track anymore due ot the fact that i had very little insight. i'm still working on it as of right now, but i'm juts letting you all know that the deadline to get the car running has passed. thx anyways...

12-01-2004, 10:42 PM	#1
psychedelicbeats Zilvia Addict Join Date: May 2003 Location: Southern CA Age: 40 Posts: 823 Trader Rating: (0) Feedback Score: 0 reviews	car jolting like a mother fuc.... under 2000rpms help i shitted my pants driving home (s14). i am breaking in my manual tranny (s13) from swap. before this problem, everything was ok. ran 100% good. nothing is wired up at the moment, but the ghetto rig to start up the car. now (as of dec 1, 2004), in any gear.... if the car is being pushed WOT from under 2000rpms, it will go jolting/lurching like crazy bouncing up and down on the revs. it feels like it's hitting the rev limiter and goes crazy if you know what i mean, and more violently like a stall. i tried driving it with a slow acceleration and it is good. after 2000rpms, with WOT it will run fine, but anything below it will cause the car to lurch/jolt/hesitate violently. i'm not sure if this will be tranny and/or electrical related(headed more to electrical related because the tranny feels good), but i am headed to the track on sunday and i need help fast. any help appreciated thanks. my aim sn is psychedelicbeats Last edited by psychedelicbeats; 12-02-2004 at 12:48 PM..

12-02-2004, 08:46 AM	#3
orion::S14 Nissanaholic! Join Date: May 2003 Location: Orange Park, FL Posts: 1,666 Trader Rating: (0) Feedback Score: 0 reviews	Sounds like you left the wrong TPS plug connected, or something (Or left the TPS disconnected all together). Auto cars have 2 TPS plugs: One for the auto trans, the other for the ECU. The auto trans one is a kickdown switch...so it reads nothing or +4v (IIRC). Check those. - Brian __________________ www.KA24DEvelopment.com

12-02-2004, 01:18 PM	#5
95Blue240sx Post Whore! Join Date: Jul 2002 Location: Girls pee-pee when they see me Age: 41 Posts: 4,084 Trader Rating: (0) Rides Gallery: 95Blue240sx Feedback Score: 0 reviews	check you mafs??? __________________ Please leave me feedback

12-02-2004, 09:26 PM	#9
orion::S14 Nissanaholic! Join Date: May 2003 Location: Orange Park, FL Posts: 1,666 Trader Rating: (0) Feedback Score: 0 reviews	'91 ECU has a different plug, and is NOT compatible at all with an S14. You need to try another S14 ECU. Or just make sure the plug is tight on yours...I've heard of crazy problem when the connector isn't tight, or not on straight. - Brian __________________ www.KA24DEvelopment.com

12-03-2004, 08:25 AM	#11
orion::S14 Nissanaholic! Join Date: May 2003 Location: Orange Park, FL Posts: 1,666 Trader Rating: (0) Feedback Score: 0 reviews	Bad fuel pump would not run well at WOT... ??? - Brian __________________ www.KA24DEvelopment.com

12-02-2004, 12:32 AM	#2
psychedelicbeats Zilvia Addict Join Date: May 2003 Location: Southern CA Age: 40 Posts: 823 Trader Rating: (0) Feedback Score: 0 reviews	tps related?

12-02-2004, 12:46 PM	#4
psychedelicbeats Zilvia Addict Join Date: May 2003 Location: Southern CA Age: 40 Posts: 823 Trader Rating: (0) Feedback Score: 0 reviews	i've double checked and it's connected correctly. haven't used the multimeter yet but will definitely soon. this is definitely an electrical problem. again, the car will not respond to WOT. ecu calculations are not going in right... could this involve speed sensor problem?

12-02-2004, 03:38 PM	#6
psychedelicbeats Zilvia Addict Join Date: May 2003 Location: Southern CA Age: 40 Posts: 823 Trader Rating: (0) Feedback Score: 0 reviews	of course. maf is not an issue. i checked the independance of wot on the tps and it reads around 1.02ohm. is this correct? full closed is .5ohm, partially open is around 3.16ohm

12-02-2004, 09:01 PM	#8
psychedelicbeats Zilvia Addict Join Date: May 2003 Location: Southern CA Age: 40 Posts: 823 Trader Rating: (0) Feedback Score: 0 reviews	during this diagnosis, i figured i would goto a shop (aerodyne) and get some more info. they told me that the ecu is throwing mixed codes each time... almost every code, and that it is a major electrical issue. would the tps actually have caused this problem to start off? i'm gonna use a 91' ecu and tps tomorrow and see what's going on. any help appreciated here. to all: symtom: ecu going crazy problem: ? bad ecu? would a bad ecu even start the car?

12-03-2004, 12:33 AM	#10
psychedelicbeats Zilvia Addict Join Date: May 2003 Location: Southern CA Age: 40 Posts: 823 Trader Rating: (0) Feedback Score: 0 reviews	could this involve fuel pump issues? what are the symtoms of a bad fuel pump?

12-03-2004, 09:06 AM	#12
yellow_jacket Leaky Injector Join Date: May 2003 Location: GA Age: 47 Posts: 52 Trader Rating: (0) Feedback Score: 0 reviews	If this is throwing all sorts of codes, then that is usually indicative of a wiring problem. The most common being a bad ground. If you recently replaced the ecu or wiring harness, I would remove the plugs and look at the pins. If there is any dielectral grease, remove it. Look for any discoloration of the male and female pins. Look at the females and make sure they are not opened up. Basically, make sure you have great connections. Then start looking at your grounds.

12-03-2004, 04:15 PM	#13
psychedelicbeats Zilvia Addict Join Date: May 2003 Location: Southern CA Age: 40 Posts: 823 Trader Rating: (0) Feedback Score: 0 reviews	this is getting way closer to fuel pump issue but i donno yet. i haven't felt a bad fuel pump before. the problem that i have is like 3000-0-3000-0-3000-0-etc at WOT. it feels like an electrical issue(goes up and down fast), but again i've never rode on a car with a bad fuel pump. well back to getting it fixed. any help appreciated here. edit: car STALLS now when trying to accelerate off on gear 1. the car goes bazerk and then it's basically shut off. Last edited by psychedelicbeats; 12-03-2004 at 11:09 PM..

12-04-2004, 12:13 AM	#14
psychedelicbeats Zilvia Addict Join Date: May 2003 Location: Southern CA Age: 40 Posts: 823 Trader Rating: (0) Feedback Score: 0 reviews	thanks for the help so far, but bump bump bump it up for more help. this is indeed an electrical problem. it lies at the intake manifold side where the egr valve is located. there's a couple of sensors inbetween the manifold there. whenever the key is turned from 1 to 2, it will make a buzzing, static-y sound. could someone elaborate with me and help me figure out what is going on. Last edited by psychedelicbeats; 12-04-2004 at 03:00 AM..

12-04-2004, 10:35 PM	#15
psychedelicbeats Zilvia Addict Join Date: May 2003 Location: Southern CA Age: 40 Posts: 823 Trader Rating: (0) Feedback Score: 0 reviews	thanks for all of hte help everyone, but i dont think i'm gonna hit the track anymore due ot the fact that i had very little insight. i'm still working on it as of right now, but i'm juts letting you all know that the deadline to get the car running has passed. thx anyways...