sr20det start-up

csappleman · Post by **csappleman** » Sun Oct 10, 2004 3:01 pm

New to the forum as well as new to the roadster itself. I am trying to squeeze the sr20det into the car and need help with all the wiring and such. I have the ecu, cut harness, motor, and all the sensors. What I really need to know is what sensors the computer needs to have to start say on a crate? Or to save myself the trouble of this cut harness should I get a new harness? Open to any and all comments and how you may have done it. Thanks

Dave · Post by **Dave** » Sun Oct 10, 2004 7:29 pm

Do yourself a huge favor and get an uncut harness! Don't scrap the old cut one though. Those connectors and color coded wire are nice to have on hand. Even the uncut harness is going to need some modification. You'll be lengthening the O2 sensor and MAF sensor wires. With the old cut harness on hand you can utilize sections of the correct color and gauge wire to do your lengthening.

As for what you need connected to run, here's what I can think of off the top of my head:

Fuel pump relay
Throttle postion sensor (TPS)
Idle air control valve (IACV)
Mass airflow sensor (MAF)
Injectors
(camshaft angle sensor) CAS
Coil pack sub harness
ECU
All the standard power, ignition, and ground connections
Theres a thin octagonal electronic doo-dad that I think is part of the ignition system. It's got 2 connectors goign to opposite sides of it. Get that sucker as far from your ECU as possible as it emits EMI.
Starter

Stuff you wont need to make it run on the crate or for test firing:
O2 sensor
Temp senders (theres 2 of them)
AC clutch
Alternator

I'm sure I'm forgetting something but this will at least get you started.

Good luck!

csappleman · Post by **csappleman** » Fri Oct 22, 2004 2:46 pm

Is it possible you could go more in depth on the general power, ground ignition area. Such as giving the number of the wires needed in that area. Like I know MAF is numbers 16, and 17 wires out of the ecu.

Thanks for all the help.

spriso · Post by **spriso** » Fri Oct 22, 2004 7:22 pm

Help us help you. You have not told us what version of the SR20DET your are trying to install, what ECU you are using, what MAF you are using, etc.

There are at least six different verisons of the RWD SR20DET and many wiring differences.

If you can be more specific, we can help you on your way...

Michael
spriso.motorsports

csappleman · Post by **csappleman** » Sat Oct 23, 2004 9:42 am

The motor is a redtop s13 sr20det the 62 ecu from a 91-93 180sx or an s13 silivia 5 speed. I plan on installing a Q45 MAF and already think I know how to go about it but any info on such a switch would be helpful as well.

I have the sr20det s13 ignitor so it plugs right in. I apoligize for not giving you this info sooner or seeing that you would need it myself as it is imperiative to figuring out these questions I am giving you.

csappleman · Post by **csappleman** » Sat Oct 23, 2004 9:48 am

Also Dave what did you meen by AC clutch. I assume it has something to do with air conditioning from my limited knowledge but am wondering what you are talking about.

Dave · Post by **Dave** » Sat Oct 23, 2004 12:27 pm

Yup, you got it. "AC Clutch" is the air conditioning compressor clutch. When you press the air conditioning button on your dash to turn it on, 12 volts is sent to the AC clutch. This engages a clutch that allows the air conditioning compressor to begin pumping refrigerant through your air conditioning system. Since you probably have long since removed the air conditioning compressor from the engine (it's a bit larger than your alternator and driven by one of the fan belts), it's one less connector to worry about connecting.

Do you have a 240SX wiring diagram and ECU pin-out list yet? You absolutely need both of those! If not, you can probably find them on-line. Or, if that falls through, send me PM with either your address or a fax number. I can mail/fax you a copy of both if you like.

Dave

spriso · Post by **spriso** » Sat Oct 23, 2004 12:35 pm

Here is the plug layout for the S13 red top SR20DET harness:

Japanese SR20DET ECU pinouts
ECU PINS Description of use
1 Coil pack 1 output (via power transistor Unit)
2 Coil pack 2 output (via power transistor Unit)
3 Tachometer signal output
4 ECCS relay
5 Ignition pulse monitor (for trip comp ?)
6 Ignition Signal Ground
7 RX data (signal from Nissan Consult hand terminal)
8 Coil pack 3 output (via power transistor Unit)
9 Coil pack 4 output (via power transistor Unit)
10 -
11 -
12 A/T signal DT3 (autotrans gear select ?)
13 Ignition Signal Ground
14 CLK clock (timing signal) ?
15 TX data (signal to Nissan Consult hand terminal)
16 AFM Signal input (air flow meter)
17 AFM ground
18 Water temp sensor input
19 Oxygen Sensor input (O2)
20 TPS input (throttle position sensor)
21 Sensor ground
22 CAS 180deg signal (crank angle sensor)
23 CHK check (check start) ?
24 Monitor check lamp (Red) (fault code lamp output)
25 Exhaust over temp warning lamp output
26 Exhaust temp sensor input (behind the Cat)
27 Detonation sensor input (knock sensor)
28 TPS for A/T (kick down switch)
29 Sensor ground
30 CAS 180deg signal (crank angle sensor)
31 CAS 1deg signal (crank angle sensor)
32 Speed sensor input
33 -
34 START signal (from ignition switch)
35 A/T neutral switch input
36 IGN (ignition ON, from ignition switch)
37 TPS power output (power to throttle position sensor)
38 ECCS power
39 ECCS ground
40 CAS 1deg signal (crank angle sensor)
41 A/C on input (Air Con ON from A/C panel or climate control)
42 A/T signal DT1 (auto trans gear select ?)
43 Power steering switch (speed proportional control output)
44 A/T signal DT1 (auto trans gear select ?)
45 Ambient air temp sensor input
46 ECCS backup power
47 ECCS power
48 ECCS ground
101 Injector No 1 drive output
102 EAI control solenoid output (EGR valve control ?)
103 Injector No 3 drive output
104 Fuel pump relay output
105 Fuel pressure control module
106 A/C on output (Air Conditioner on relay signal)
107 Injector ground
108 Injector ground
109 Reverse electrical flow return circuit (alternator fail input ?)
110 Injector No 2 drive output
111 Turbo boost pressure control solenoid (over boost cut ?)
112 Injector No 4 drive output
113 AAC valve control (Auxiliary Air Control, idle speed control)
114 -
115 -
116 Injector ground

csappleman · Post by **csappleman** » Sat Oct 23, 2004 4:17 pm

Yes I have the pin out from the ECU as well as a wiring diagram. I have an idea of what is needed for iginition and such just wondering on how you did it to make sure I don't screw anything up.

Thanks for the pin out and list to check against the one I already have. I appreciate all the help very much as well.

csappleman · Post by **csappleman** » Sat Oct 23, 2004 8:53 pm

For Example did you have to hook #'s 6, 13, 39, 48 to ground for ignition and ground for the ECCS or are there more wires to worry about. Also did you hook #'s 34, 36 to the ignition switch and #'s 38, 46, 47 to 12V.

Thanks for all your help in advance.

csappleman · Post by **csappleman** » Tue Oct 26, 2004 8:26 pm

Ummm, did you understand my last two questions or should I try to ask them a different way. Thanks

TR · Post by TR » Wed Oct 27, 2004 1:34 am

Sorry none of us have replied, speaking for myself (and probably others), time is precious and short...

From my notes, these are the minimum connections needed to make the car start (of course, check against your specific model and diagram, etc.):

Pin 4 (R-B) - This is used as a ground sink trigger wire for the ECU relay
Pins 38 & 47 (B-W) - Power to the ECU from the ECU relay

Pin 34 (Or) - To IG$ 'START' via a 10A Fuse
Pin 36 (B-R) - To IG$ 'ON'
Pins 46 & 109 (R) - To B+ via Fuse, also powers the injectors
Pin 104 (B-P) - Ground sink trigger wire for Fuel Pump relay

From the engine harness there are three wires that require connection to the IG$ 'ON' via fuses: L-R, Brn, & B-Y (ignition coils, O2 & AAC Power).

So yes, you are really close, just don't forget to power up the other items and get those fuses and relays in there to protect the systems...TR

csappleman · Post by **csappleman** » Sun Nov 28, 2004 4:44 pm

Hi,
re-opening this discussion as I need more info. I have everything hooked up that TR, Dave, and Micheal have mentioned here except the ground sink triggers that TR mentioned. I am hoping that I don't really need the relay's for start up on a crate but I don't know what voltage to send through these wires(is it a ground do you put power through them. If I absolutely need the relays I would obviously get them but if I don't then I don't want to have to go out and buy anything more at the moment. I need help on this matter ASAP. Thanks Casey

TR · Post by TR » Sun Nov 28, 2004 5:00 pm

You can power the fuel pump and ecu without the relays, just leave the trigger wires from the ecu (4&104) insulated...Good Luck! TR

csappleman · Post by **csappleman** » Sun Nov 28, 2004 5:46 pm

TR/all,
Also I know I have power to the ecu at the 4 power input points through using a multimeter but I do not see the red led light coming on at the back of the ecu. Could the light be bad or would this indicate a bad ecu. Is there a way to check to see whether the ecu is bad or not. Thanks reply ASAP.
Casey