s14 rb25 help please - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

gsn0526 · 06-28-2010, 09:46 PM

s14 with rb25det, cars turning over, have all lights inside the car radio is working.....just no power to ecu. no light either. not getting fuel or spark. rb has s14 lower harness on it as far as starter alternator and tranny plugs. any help would be appreciated

greenzenki86 · 06-29-2010, 03:49 AM

do some research on google and make sure you matched up all the pins correctly on the upper harness, also make sure you youre researching for the right year, obd2/obd1.

gsn0526 · 06-29-2010, 09:50 PM

now getting fuel but no light on ecu. anyone run into this before? pins are correct.

greenzenki86 · 06-29-2010, 11:20 PM

could be a faulty ecu, try to use someone else if they let you and see if the problem persist.

Darius · 06-30-2010, 12:22 PM

Focus on the ECCS and IGN relays (blue) and make sure they have 12V where necessary and that they are switching power properly. I had mine wired up correctly and it still didn't work properly because the IGN relay was not switching closed. I had to add a manual toggle switch to ground to get the relay to close and power the ignition system.

Then one day, I modified the gray fuel injector harness power wire when I was tucking the wiring and it magically worked without the toggle switch. I say magically because I honestly don't know what I even changed that would change the gray wire connectivity.

gsn0526 · 06-30-2010, 08:35 PM

dont really know anyone else with rb25 will ask around......i know i was geting power to the relays but i will def. try your idea....will post asap. thanks.

anyone else with ideas please post im stumped at this point.

gsn0526 · 07-08-2010, 02:40 PM

from research i did it looks like the ecu is for an automatic transmission....is it possible that it would have a different pinout?

Sileighty_85 · 07-08-2010, 02:46 PM

Post up the P/N off the ECU and i can tell you what it goes to

gsn0526 · 07-08-2010, 03:01 PM

i wanna say its TJ coded ecu.....i havent been at the car since i started this thread to make 100% sure.

Sileighty_85 · 07-08-2010, 03:29 PM

Quote:

Originally Posted by gsn0526

i wanna say its TJ coded ecu.....i havent been at the car since i started this thread to make 100% sure.

Nah there should be a number like EX: 43685-93829

gsn0526 · 07-10-2010, 07:22 PM

TJ
23710 21v01
mec-r521 a1 4127

Sileighty_85 · 07-10-2010, 09:09 PM

Aight took me a minute cuz that "V" is actually a "U"

but your ECU is for a R33 93-94 RB25 Manual Transmission

gsn0526 · 07-10-2010, 11:49 PM

thanks for the help

gsn0526 · 07-12-2010, 11:36 AM

ok been at the car for couple hours now.....ign. and eccs relays are working. 12v to the pins on the ecu. still getting power interior dash and accessories. fuel pump still working. just no light on ecu.

low voltage going into power transistor. low voltage going out to the coils.

i have an open plug that ive been unsure about . it had plug for oil pressure, clip plug going to starter. also was held together with knock sensor harness. there is six wires on plug. blue/red, grey, yellow, green/orange, light blue, green/red.
is this a necessity to turn the ecu on?

Darius · 07-12-2010, 12:20 PM

What do you mean by "low voltage going out to the coils"? Does the white wire have a full 12V when the key is ON? It should. Are you measuring this at the coil packs or at the IGN relay?

The PTU shouldn't have voltage going into it because the ECU is grounding the signal wires not supplying them with voltage. The PTU shouldn't have any power except for the cyl. #1 pin on the coil harness side when the two-pin (thick white and black/red) connector is plugged in and the key is ON. If it has voltage elsewhere, there is something wrong.

gsn0526 · 07-12-2010, 12:53 PM

IGn Relay has 12V. All 7 lines into the Power Transistor have .9V on it. All 6 lines out have .9V with the ign on or cranking. Voltage does not change. Did not check the white wire going to coils directly but it is fed off position 3 of the ign. relay and that has 12V with the key on.

Darius · 07-12-2010, 02:27 PM

Double check that 12V is getting all the way up to coil #1's white wire. It probably is, but just to rule out that it might be grounding out in the coil harness (like mine did during a car show...left me stranded and pissed off).

There should be 0V voltage on the wires at the PTU. Since you are seeing 0.9V with the key ON, it sounds like there is a short somewhere in the PTU that is providing voltage to each. Do you have access to a known good PTU?

gsn0526 · 07-12-2010, 04:36 PM

The voltage into and out of the PTU is .9V. Since the voltage is prior to the PTU I would assume the short is prior to the PTU and not in the PTU. Should the PTU stop any current coming to the PTU or is it a switch point in the system?

gsn0526 · 07-14-2010, 10:42 AM

im getting 12 volt to the white wire and the test point for #1 cylinder. im leaning towards a bad ecu. am i supposed to have 12 volts to the grey wire on injectors at all times?

gsn0526 · 07-14-2010, 10:44 AM

ptu is at 0 like it should

gsn0526 · 07-17-2010, 02:45 PM

ok i tested the ecu on another rb and it started just fine.....but there isnt a light on it which i thought was weird. anyway i am back to being stumped any ideas would be helpful? timing or maybe something with injectors is my only guess at this point. but again any response will be appreciated.

Darius · 07-20-2010, 12:54 PM

Yes the gray wire to the injectors should have ON power. Where are you connecting the gray wire for power?

gsn0526 · 07-20-2010, 03:43 PM

Traced the grey wire plug in upper harness. I have no corresponding plug on the car. How does this get wired and where do I get the 12v from for the grey wire?

Darius · 07-21-2010, 06:44 AM

Quote:

Originally Posted by gsn0526

Traced the grey wire plug in upper harness. I have no corresponding plug on the car. How does this get wired and where do I get the 12v from for the grey wire?

You are correct, there is no corresponding plug for the gray wire plug on the S-chassis. You need to cut the grey wire at the plug and connect it to switched ON power. I say cut it at the plug because I initially tapped into the side of the grey wire and powered it off of the battery, but that interfered with closing the ECCS and IGN relays. It was totally weird, but once I pulled the grey wire out of the loom and rewired it to switched ON power, my car started without having to flip a manual ground switch that I installed on the ECCS relay.

In short, cut the grey wire at the plug and connect it to 12V power. It will almost certainly fire up after you do this.

gsn0526 · 07-21-2010, 07:57 PM

yea i got that im gonna put it on the relay....i hard wired just to see if she will start.. and it didnt. nothing different than before except for a strong gas smell so i know the injectors are kicking.....stumped again. just cant really think of anything else. timing? but im not even getting a misfire/backfire sound.

Darius · 07-22-2010, 07:04 AM

Have you pulled the coils and plugs and rested them on the valve cover to see if they are sparking? Please disconnect grey injector power wire before doing this if you haven't already

gsn0526 · 07-22-2010, 02:43 PM

i have not...gonna have the a couple hours to go to the car in the morning gotta do that grey wire. might have time to pull the coils. gonna have a guy named shane come and look at it supposedly he has done 11 rb swaps in thomasville/greensboro area. so hopefully he will get me pointed in right direction.

gsn0526 · 07-24-2010, 03:16 PM

shes running !!!!!!!!!!! thanks for the help. really appreciated

Darius · 07-26-2010, 07:09 AM

What was the issue? Please update

gsn0526 · 07-27-2010, 10:33 AM

the injector power wire and i had the fuel lines on wrong.(rookie mistake) thought the fpr was first. come to find out it on return. just put it on like that and havent paid attention to it.

got a problem with leaking coolant looks like it may be coming from heater core hoses.
my clutch line is leaking a just a little bit not bad at all though.

my alternator is not working ....i have the positve and ground on the correct spots but i do not have the plug in the top of it. i have the ka lower harness on the motor. where do i get this plug?

06-29-2010, 09:50 PM	#3
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	now getting fuel but no light on ecu. anyone run into this before? pins are correct. Last edited by gsn0526; 06-29-2010 at 09:51 PM.. Reason: forgot

06-29-2010, 11:20 PM	#4
greenzenki86 Zilvia Member Join Date: Jul 2009 Location: Where the palm trees grow Age: 37 Posts: 196 Trader Rating: (7) Feedback Score: 7 reviews	could be a faulty ecu, try to use someone else if they let you and see if the problem persist. __________________ Who cares if you have 800hp......

07-08-2010, 02:46 PM	#8
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Post up the P/N off the ECU and i can tell you what it goes to __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

07-10-2010, 09:09 PM	#12
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Aight took me a minute cuz that "V" is actually a "U" but your ECU is for a R33 93-94 RB25 Manual Transmission __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

06-28-2010, 09:46 PM	#1
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	s14 rb25 help please s14 with rb25det, cars turning over, have all lights inside the car radio is working.....just no power to ecu. no light either. not getting fuel or spark. rb has s14 lower harness on it as far as starter alternator and tranny plugs. any help would be appreciated

06-29-2010, 03:49 AM	#2
greenzenki86 Zilvia Member Join Date: Jul 2009 Location: Where the palm trees grow Age: 37 Posts: 196 Trader Rating: (7) Feedback Score: 7 reviews	do some research on google and make sure you matched up all the pins correctly on the upper harness, also make sure you youre researching for the right year, obd2/obd1.

06-30-2010, 12:22 PM	#5
Darius Zilvia Junkie Join Date: Mar 2005 Location: Chicago Posts: 346 Trader Rating: (5) Feedback Score: 5 reviews	Focus on the ECCS and IGN relays (blue) and make sure they have 12V where necessary and that they are switching power properly. I had mine wired up correctly and it still didn't work properly because the IGN relay was not switching closed. I had to add a manual toggle switch to ground to get the relay to close and power the ignition system. Then one day, I modified the gray fuel injector harness power wire when I was tucking the wiring and it magically worked without the toggle switch. I say magically because I honestly don't know what I even changed that would change the gray wire connectivity.

06-30-2010, 08:35 PM	#6
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	dont really know anyone else with rb25 will ask around......i know i was geting power to the relays but i will def. try your idea....will post asap. thanks. anyone else with ideas please post im stumped at this point.

07-08-2010, 02:40 PM	#7
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	from research i did it looks like the ecu is for an automatic transmission....is it possible that it would have a different pinout?

07-08-2010, 03:01 PM	#9
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	i wanna say its TJ coded ecu.....i havent been at the car since i started this thread to make 100% sure.

07-10-2010, 07:22 PM	#11
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	TJ 23710 21v01 mec-r521 a1 4127

07-10-2010, 11:49 PM	#13
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	thanks for the help

07-12-2010, 11:36 AM	#14
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	ok been at the car for couple hours now.....ign. and eccs relays are working. 12v to the pins on the ecu. still getting power interior dash and accessories. fuel pump still working. just no light on ecu. low voltage going into power transistor. low voltage going out to the coils. i have an open plug that ive been unsure about . it had plug for oil pressure, clip plug going to starter. also was held together with knock sensor harness. there is six wires on plug. blue/red, grey, yellow, green/orange, light blue, green/red. is this a necessity to turn the ecu on?

07-12-2010, 12:20 PM	#15
Darius Zilvia Junkie Join Date: Mar 2005 Location: Chicago Posts: 346 Trader Rating: (5) Feedback Score: 5 reviews	What do you mean by "low voltage going out to the coils"? Does the white wire have a full 12V when the key is ON? It should. Are you measuring this at the coil packs or at the IGN relay? The PTU shouldn't have voltage going into it because the ECU is grounding the signal wires not supplying them with voltage. The PTU shouldn't have any power except for the cyl. #1 pin on the coil harness side when the two-pin (thick white and black/red) connector is plugged in and the key is ON. If it has voltage elsewhere, there is something wrong.

07-12-2010, 12:53 PM	#16
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	IGn Relay has 12V. All 7 lines into the Power Transistor have .9V on it. All 6 lines out have .9V with the ign on or cranking. Voltage does not change. Did not check the white wire going to coils directly but it is fed off position 3 of the ign. relay and that has 12V with the key on.

07-12-2010, 02:27 PM	#17
Darius Zilvia Junkie Join Date: Mar 2005 Location: Chicago Posts: 346 Trader Rating: (5) Feedback Score: 5 reviews	Double check that 12V is getting all the way up to coil #1's white wire. It probably is, but just to rule out that it might be grounding out in the coil harness (like mine did during a car show...left me stranded and pissed off). There should be 0V voltage on the wires at the PTU. Since you are seeing 0.9V with the key ON, it sounds like there is a short somewhere in the PTU that is providing voltage to each. Do you have access to a known good PTU?

07-12-2010, 04:36 PM	#18
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	The voltage into and out of the PTU is .9V. Since the voltage is prior to the PTU I would assume the short is prior to the PTU and not in the PTU. Should the PTU stop any current coming to the PTU or is it a switch point in the system?

07-14-2010, 10:42 AM	#19
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	im getting 12 volt to the white wire and the test point for #1 cylinder. im leaning towards a bad ecu. am i supposed to have 12 volts to the grey wire on injectors at all times?

07-14-2010, 10:44 AM	#20
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	ptu is at 0 like it should

07-17-2010, 02:45 PM	#21
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	ok i tested the ecu on another rb and it started just fine.....but there isnt a light on it which i thought was weird. anyway i am back to being stumped any ideas would be helpful? timing or maybe something with injectors is my only guess at this point. but again any response will be appreciated.

07-20-2010, 12:54 PM	#22
Darius Zilvia Junkie Join Date: Mar 2005 Location: Chicago Posts: 346 Trader Rating: (5) Feedback Score: 5 reviews	Yes the gray wire to the injectors should have ON power. Where are you connecting the gray wire for power?

07-20-2010, 03:43 PM	#23
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	Traced the grey wire plug in upper harness. I have no corresponding plug on the car. How does this get wired and where do I get the 12v from for the grey wire?

07-21-2010, 07:57 PM	#25
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	yea i got that im gonna put it on the relay....i hard wired just to see if she will start.. and it didnt. nothing different than before except for a strong gas smell so i know the injectors are kicking.....stumped again. just cant really think of anything else. timing? but im not even getting a misfire/backfire sound.

07-22-2010, 07:04 AM	#26
Darius Zilvia Junkie Join Date: Mar 2005 Location: Chicago Posts: 346 Trader Rating: (5) Feedback Score: 5 reviews	Have you pulled the coils and plugs and rested them on the valve cover to see if they are sparking? Please disconnect grey injector power wire before doing this if you haven't already

07-22-2010, 02:43 PM	#27
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	i have not...gonna have the a couple hours to go to the car in the morning gotta do that grey wire. might have time to pull the coils. gonna have a guy named shane come and look at it supposedly he has done 11 rb swaps in thomasville/greensboro area. so hopefully he will get me pointed in right direction.

07-24-2010, 03:16 PM	#28
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	shes running !!!!!!!!!!! thanks for the help. really appreciated

07-26-2010, 07:09 AM	#29
Darius Zilvia Junkie Join Date: Mar 2005 Location: Chicago Posts: 346 Trader Rating: (5) Feedback Score: 5 reviews	What was the issue? Please update

07-27-2010, 10:33 AM	#30
gsn0526 Leaky Injector Join Date: Mar 2009 Location: greensboro north carolina Posts: 115 Trader Rating: (0) Feedback Score: 0 reviews	the injector power wire and i had the fuel lines on wrong.(rookie mistake) thought the fpr was first. come to find out it on return. just put it on like that and havent paid attention to it. got a problem with leaking coolant looks like it may be coming from heater core hoses. my clutch line is leaking a just a little bit not bad at all though. my alternator is not working ....i have the positve and ground on the correct spots but i do not have the plug in the top of it. i have the ka lower harness on the motor. where do i get this plug?