No ECU power, - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

SGTRanger175 · 03-29-2011, 07:52 AM

NOTE: This is a Blacktop S14 SR20DET w/VVT into a USDM 1997 S14.

I have everything installed. All the necessary plugs are plugged in (those required to at least get the car running, ECU, ignition, F4, etc.)

The car is a USDM 97 S14, Blacktop S14 SR, NB ECU and from what wiring specialties said the harness is the late model harness. It has the smaller plug with smaller ABS plug near the ECU.

I am not using the ABS plug as you would imagine. I repinned the F4 exactly as the KA plug was wired. Repinned it with what was available from the harness we are using.

I did leave out the following from the F4 plug. Each left out wire was heat-shrinked individually, bundled and heat-shrinked again.:
Fan relay wires (orange/blue),
Knock Sensor Ground (gray),
IACV (black/yellow),
Check Connector (Green/Red)

Also I noticed on the this diagram (http://img241.imageshack.us/img241/8...1052006wu0.png) that the KA plug has a ground wire at #39 so I added a black ground wire and attached to to where the ECU grounds at.

Here are some photos to put these words into context.

Hope you all can help me out. Been trying to wire this thing for over a week. The car will crank, but I have no power to the ECU. The dash lights up, but no CEL to show power to the ECU either. (No spark, fuel, etc.)

Thanks in advance!

The black/yellow wire, I verified goes to the IACV. Verified the continuity between the the F4 pin and IACV plug. .0003 Ohm.

Pictures of the ECU, can you help me decode exactly which ECU this is and is it compatible with what I am using?

SGTRanger175 · 03-29-2011, 10:51 AM

Update:!!!!!

Now have power to the ECU. There was a bad blue relay. Luckily we had another one. Replaced the relay, "LET THERE BE LIGHT"!

Also this gave us spark as well. However it appears we have no fuel, pump is running, we are about to check fuel pressure and whether the injectors are firing or not. Pulled a plug and didn't see/smell fuel.

Will update again a little later with results.

bb4_96 · 03-29-2011, 10:54 AM

Best troubleshoot post ever.

SGTRanger175 · 03-29-2011, 11:30 AM

Well we def have fuel pressure. At first I thought the fuel lines were reversed but they aren't.

Incoming fuel is going to the top left metal line, return is coming off the bottom right line that runs from the bottom of the fuel pressure regulator. The motor bumped for a fraction of a second making my heart about skip a beat or increase in rate. But still no running motor.

The battery is pretty weak so we are fast charging it to get some juice.

Sileighty_85 · 03-29-2011, 12:05 PM

Just a FYI That ECU is from a 96 Auto, If that helps at all

Id check plugs and make sure they are gaped correctly at .028

SGTRanger175 · 03-29-2011, 01:25 PM

The car will run off of starter fluid (spray). Has to be an issue with the injectors. I will finish diagnosing it when I get back to the shop in about 20 minutes.

SGTRanger175 · 03-29-2011, 03:12 PM

Ok I am getting the 5v to the injectors, we have ~40psi of fuel, we have spark.

Whats the chance that we have 4 bad injectors? Ugh.

SGTRanger175 · 03-29-2011, 04:39 PM

Ok so Im thinking this through:

We have spark, we have 40+psi of fuel, we have voltage to the injectors and we got air.

I crank it over a few times, pull the plugs to verify fuel again and it doesn't smell of fuel at all. The odds of having four bad injectors is pretty slim.
Now when I spray starter fluid into the intake the car will start and run.

Maybe the injectors are just really dirty and clogged up or something really abnormal like black magic. Perhaps we are just having a lean misfire...??? O_o The turbo is pretty small and putting air into the motor, maybe its just too much. its a T25 so it doesn't have a port on the housing for the wastegate. But even at idle and startup it should matter anyways. Anywho, I take off the charge elbow and prep it for a new port and take off the intercooler piping at the throttle body. MAF is still on the turbo so at least there is some kind of reading for the ECU to see.

(BTW isnt the VTC SR20DET supposed to have a T28, i thought all the Nissan T28's had a port on the compressor housing for the wastegate line..???)

So I decide to start it up again and I spray a lot or stating fluid into the intake to get it running for a little while. She starts running as expected. Well after I stop spraying she continues to run even after all the fluid should have been consumed.

So it appears that since this motor hasn't been run in god knows how long that it was having a lean misfire. Without the turbo hooked up the car will run.

So tomorrow I will get it all back together with the new port for the wastegate and get her started again.

I will update this tomorrow with results.

Pro ViZIon · 03-29-2011, 06:28 PM

Ohm test your injectors just to make sure. And check all harness grounds.

Sileighty_85 · 03-29-2011, 07:11 PM

you should have 12V at the injectors

a7olyte · 03-29-2011, 07:20 PM

You need 12v at the injectors. I can't tell whether or not you bypassed the injector 12v wire or not, but from the pictures supplied it seems to be missing.

From the diagrams you have supplied, Pin 48 is Power to Injectors, which is missing in your dash harness. I don't know how accurate the diagram is, but assuming it's correct, you are missing that wire (unless you bypassed it). I've attached a picture that may be a fix to your problem.

SGTRanger175 · 03-29-2011, 09:53 PM

The battery has been really undercharged all day. So that could be the case as well. I put it on a slow charge over night.

I actually fell asleep in my recliner about 4 hours ago. I just woke up, but Im going to take advantage of it and head back to bed.

When i got into the shop in the morning I will recheck everything when the battery is fully charged.

SGTRanger175 · 03-30-2011, 11:02 AM

So can I just run a 12v power source from the ignition to this plug then? Can I just splice the it off the fuel pump power source? There was no Red/Yellow wire in this location for either the SR harness I have or in the KA original F3 plug.

Quote:

Originally Posted by a7olyte

You need 12v at the injectors. I can't tell whether or not you bypassed the injector 12v wire or not, but from the pictures supplied it seems to be missing.

From the diagrams you have supplied, Pin 48 is Power to Injectors, which is missing in your dash harness. I don't know how accurate the diagram is, but assuming it's correct, you are missing that wire (unless you bypassed it). I've attached a picture that may be a fix to your problem.

SGTRanger175 · 03-30-2011, 11:37 AM

From the FSM I see that the injectors have a continuous power source (battery voltage, should be 12.6v). This is a BLACK/YELLOW wire which is in pin

The ECU provides the grounding for the injectors. The BLACK/RED is in the same location on both the KA and SR harnesses so I did not repin it. (Bottom right corner as you can see in the above photo.

The Red/Yellow wire that was mentioned earlier is on the KA harness and runs from the F3 plug to the ECU pin #60. I found a pinout of the ECU however it does not indicate what it is a power source for. Also its to the left of the (BLACK/PINK: KA F3), (Black/Yellow on the F4 SR) wire that is the fuel pump relay power source.

SGTRanger175 · 03-30-2011, 01:24 PM

Double checked the power wire from the F4 to the injector harness junction plug and its good.

The car will run after getting it started with starting fluid but it runs really rough. You have to adjust the throttle to keep the car running. it will smooth out at higher rpm but idle its barely alive or dies.

SGTRanger175 · 03-30-2011, 07:00 PM

Got the start-up issue somewhat resolved. Found out that one of the ORANGE/BLUE wires is the Start signal and only one is for the Fan Relay. The Orange wire on the SR F4 is the Malfunction indicator.

Now I have a loose BLACK/WHITE wire that I cant seem to track down as to what its for and where it goes.

SGTRanger175 · 04-01-2011, 06:21 AM

I appears we have most of the core issues resolved now. However the idle still sucks and startup isnt perfect.

The car is also operating under a revlimit so we beleive its either an issue with the MAFS or ECU. Seeking a good known unit to test.

03-29-2011, 07:52 AM	#1
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	No ECU power, No Spark, No fuel. NOTE: This is a Blacktop S14 SR20DET w/VVT into a USDM 1997 S14. I have everything installed. All the necessary plugs are plugged in (those required to at least get the car running, ECU, ignition, F4, etc.) The car is a USDM 97 S14, Blacktop S14 SR, NB ECU and from what wiring specialties said the harness is the late model harness. It has the smaller plug with smaller ABS plug near the ECU. I am not using the ABS plug as you would imagine. I repinned the F4 exactly as the KA plug was wired. Repinned it with what was available from the harness we are using. I did leave out the following from the F4 plug. Each left out wire was heat-shrinked individually, bundled and heat-shrinked again.: Fan relay wires (orange/blue), Knock Sensor Ground (gray), IACV (black/yellow), Check Connector (Green/Red) Also I noticed on the this diagram (http://img241.imageshack.us/img241/8...1052006wu0.png) that the KA plug has a ground wire at #39 so I added a black ground wire and attached to to where the ECU grounds at. Here are some photos to put these words into context. Hope you all can help me out. Been trying to wire this thing for over a week. The car will crank, but I have no power to the ECU. The dash lights up, but no CEL to show power to the ECU either. (No spark, fuel, etc.) Thanks in advance! The black/yellow wire, I verified goes to the IACV. Verified the continuity between the the F4 pin and IACV plug. .0003 Ohm. Pictures of the ECU, can you help me decode exactly which ECU this is and is it compatible with what I am using? Last edited by SGTRanger175; 03-30-2011 at 01:28 PM..

03-29-2011, 12:05 PM	#5
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Just a FYI That ECU is from a 96 Auto, If that helps at all Id check plugs and make sure they are gaped correctly at .028 __________________ 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

03-29-2011, 06:28 PM	#9
Pro ViZIon Zilvia Junkie Join Date: Dec 2008 Location: Las Vegas, NV Age: 31 Posts: 415 Trader Rating: (0) Feedback Score: 0 reviews	Ohm test your injectors just to make sure. And check all harness grounds. __________________ 1990 Nissan 240SX w/KA24DE - New project 1984 Mazda RX-7 GSL-SE 13B

03-29-2011, 07:11 PM	#10
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	you should have 12V at the injectors __________________ 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

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03-29-2011, 10:51 AM	#2
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	Update:!!!!! Now have power to the ECU. There was a bad blue relay. Luckily we had another one. Replaced the relay, "LET THERE BE LIGHT"! Also this gave us spark as well. However it appears we have no fuel, pump is running, we are about to check fuel pressure and whether the injectors are firing or not. Pulled a plug and didn't see/smell fuel. Will update again a little later with results.

03-29-2011, 10:54 AM	#3
bb4_96 Zilvia Addict Join Date: Jan 2006 Location: Under my car Posts: 785 Trader Rating: (4) Feedback Score: 4 reviews	Best troubleshoot post ever.

03-29-2011, 11:30 AM	#4
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	Well we def have fuel pressure. At first I thought the fuel lines were reversed but they aren't. Incoming fuel is going to the top left metal line, return is coming off the bottom right line that runs from the bottom of the fuel pressure regulator. The motor bumped for a fraction of a second making my heart about skip a beat or increase in rate. But still no running motor. The battery is pretty weak so we are fast charging it to get some juice.

03-29-2011, 01:25 PM	#6
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	The car will run off of starter fluid (spray). Has to be an issue with the injectors. I will finish diagnosing it when I get back to the shop in about 20 minutes.

03-29-2011, 03:12 PM	#7
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	Ok I am getting the 5v to the injectors, we have ~40psi of fuel, we have spark. Whats the chance that we have 4 bad injectors? Ugh.

03-29-2011, 04:39 PM	#8
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	Ok so Im thinking this through: We have spark, we have 40+psi of fuel, we have voltage to the injectors and we got air. I crank it over a few times, pull the plugs to verify fuel again and it doesn't smell of fuel at all. The odds of having four bad injectors is pretty slim. Now when I spray starter fluid into the intake the car will start and run. Maybe the injectors are just really dirty and clogged up or something really abnormal like black magic. Perhaps we are just having a lean misfire...??? O_o The turbo is pretty small and putting air into the motor, maybe its just too much. its a T25 so it doesn't have a port on the housing for the wastegate. But even at idle and startup it should matter anyways. Anywho, I take off the charge elbow and prep it for a new port and take off the intercooler piping at the throttle body. MAF is still on the turbo so at least there is some kind of reading for the ECU to see. (BTW isnt the VTC SR20DET supposed to have a T28, i thought all the Nissan T28's had a port on the compressor housing for the wastegate line..???) So I decide to start it up again and I spray a lot or stating fluid into the intake to get it running for a little while. She starts running as expected. Well after I stop spraying she continues to run even after all the fluid should have been consumed. So it appears that since this motor hasn't been run in god knows how long that it was having a lean misfire. Without the turbo hooked up the car will run. So tomorrow I will get it all back together with the new port for the wastegate and get her started again. I will update this tomorrow with results.

03-29-2011, 07:20 PM	#11
a7olyte Leaky Injector Join Date: Oct 2006 Location: CA Age: 37 Posts: 63 Trader Rating: (5) Feedback Score: 5 reviews	You need 12v at the injectors. I can't tell whether or not you bypassed the injector 12v wire or not, but from the pictures supplied it seems to be missing. From the diagrams you have supplied, Pin 48 is Power to Injectors, which is missing in your dash harness. I don't know how accurate the diagram is, but assuming it's correct, you are missing that wire (unless you bypassed it). I've attached a picture that may be a fix to your problem.

03-29-2011, 09:53 PM	#12
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	The battery has been really undercharged all day. So that could be the case as well. I put it on a slow charge over night. I actually fell asleep in my recliner about 4 hours ago. I just woke up, but Im going to take advantage of it and head back to bed. When i got into the shop in the morning I will recheck everything when the battery is fully charged.

03-30-2011, 11:37 AM	#14
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	From the FSM I see that the injectors have a continuous power source (battery voltage, should be 12.6v). This is a BLACK/YELLOW wire which is in pin The ECU provides the grounding for the injectors. The BLACK/RED is in the same location on both the KA and SR harnesses so I did not repin it. (Bottom right corner as you can see in the above photo. The Red/Yellow wire that was mentioned earlier is on the KA harness and runs from the F3 plug to the ECU pin #60. I found a pinout of the ECU however it does not indicate what it is a power source for. Also its to the left of the (BLACK/PINK: KA F3), (Black/Yellow on the F4 SR) wire that is the fuel pump relay power source.

03-30-2011, 01:24 PM	#15
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	Double checked the power wire from the F4 to the injector harness junction plug and its good. The car will run after getting it started with starting fluid but it runs really rough. You have to adjust the throttle to keep the car running. it will smooth out at higher rpm but idle its barely alive or dies.

03-30-2011, 07:00 PM	#16
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	Got the start-up issue somewhat resolved. Found out that one of the ORANGE/BLUE wires is the Start signal and only one is for the Fan Relay. The Orange wire on the SR F4 is the Malfunction indicator. Now I have a loose BLACK/WHITE wire that I cant seem to track down as to what its for and where it goes.

04-01-2011, 06:21 AM	#17
SGTRanger175 Join Date: Mar 2011 Location: USA Posts: 23 Trader Rating: (0) Feedback Score: 0 reviews	I appears we have most of the core issues resolved now. However the idle still sucks and startup isnt perfect. The car is also operating under a revlimit so we beleive its either an issue with the MAFS or ECU. Seeking a good known unit to test.