View Full Version : Sr20det 1st cyl has spark, other 3 do not.

03-09-2012, 01:56 PM
What would cause the first cylinder to be getting fire, but not the 2nd-4th? All of the coil packs are good as are the plugs. I tested them all through the first plug on the coil pack harness. The connections are good in the harness (took the loom off and looked). I'm stumped.

03-09-2012, 02:48 PM
Just bought a volt meter and checked the coil pack harness. It's got 12 volts at the power splice...

03-09-2012, 05:44 PM
Can an ignitor chip be bad and still give great spark to one cylinder? Seems to me that what ever controls the signal wire portion of the coil pack harness isn't working. What controls that, the CAS? I'll be pissed if that's bad because I bought it off of a member on here a while back and haven't used it until today.

03-09-2012, 06:28 PM
My guess is CAS but igniter chips can cause your problems too. Find a sr friend and swap parts.

Try to replicate the symptoms on your friends car with your parts.

03-09-2012, 08:56 PM
I don't have any SR friends locally. I'm hoping someone can chime in here. It's had to have happened to someone here, theres just too much off topic bullshit to sift through to actually get to the automotive problems... I'm guessing it's the CAS simply because it's the only part thy I can think that has control over the signals going to the coil packs. I just don't want to spend a $100 more bucks for a trial and error.

http://zilvia.net/f/tech-talk/390737-another-sr20det-no-spark-help-please.html After reading this thread from a while back, post 10 was very informative (wish there were more people like that guy on the forum), and now the Ignitor is sounding plausible too, since each coil pack has its own resistor in the chip. Possibly 2-4 are bad and 1 is the only good one. I will buy another ignitor and then update this thread for the next guy that's looking for 240sx solutions instead of writing about other dumb shit. Hopefully it's just the ignitor. Guess we'll see.

03-17-2012, 08:52 AM
I swapped the ignitor chip out and still having the same issues. I did notice that coil pack 3 can be warm at times when the other three aren't. And I was getting spark on 1 and 3 last night after changing computers (I have 2)... The ignitor gets so hot that it will burn you, so I started untaping the loom to see if there's a possible short. After untaping everything, I had spark on all 4 coils for a very short time, but after a little more dilly dallying, it went back to only 1 and 3... What gives man? Anybody have any ideas as to why this is happening? What would cause that ignitor to get so damn hot? And it happens with both ignitors, same symptoms... I don't think its the ignitor itself.

03-17-2012, 01:15 PM
something in the wiring if it worked temporarily while you fiddled with it. i guess id say start with a volt meter, and trace each coil pack back to the ignitor, and ultimately to the ecu, make sure there are no shorts/frays/ serious creases in the wire. these can cause conductivity issues, and coil packs need that voltage

03-17-2012, 08:45 PM
Yeah the harness is all folded over and taped really tight from being Rhd to Lhd (Sr20)... So all of the wires are folded over pretty tightly. Is the ignitor suppose to get hot enough to burn you when the ignition is turned on? I also notice coil pack 3 is very warm compared to the others.

03-17-2012, 09:51 PM
The ignitor should not be getting that hot. You have a short somewhere, or the ignitor is toast. It can be warm to the touch, but shouldn't burn you.

03-17-2012, 10:13 PM
It literally burned me... Have a blister from it. And it does it to both igniters... The third coil is getting warm too, so maybe it's a short going to that cylinder...

03-22-2012, 11:35 AM
Are there any other kind of chassis wiring issues that I have to do when installing an SR manual, into a KA Auto chassis? I cut the clip off underneath the passenger side fuse box, and spliced them together, and I also switch the plug for the dash instruments, but that's it. Anything else I have to do that could be causing these symptoms? I'm heading over to my shop now to work on the harness some more to check for shorts and I'm going to try and check ECU output to those Coilpacks. Shouldnt it fluctuate while cranking it, and what should those numbers be? Any help is appreciated.

03-22-2012, 01:05 PM
Pin Wire Description
101 W/B Fuel Injector # 1 Drive Input
102 O/L EAI AIV Control Solenoid Output
103 G/B Fuel Injector # 3 Drive Input
104 B/P Fuel Pump Relay
105 R/W Fuel Pressure Control Module
106 G/Y A/C Relay
107 B Fuel Injector Ground
108 B Fuel Injector Ground
109 R ECU Current Return
110 Y/B Fuel Injector # 2 Drive Input
111 O/B Turbo Boost Pressure Control Solenoid
112 L/B Fuel Injector # 4 Drive Input
113 SB Auxiliary Air Control, Idle Speed Control
114 Br/Y (unknown function)
116 B Fuel Injector Ground
1 R/W Ignition Signal # 1
2 R/Y Ignition Signal # 2
3 Y/R Tachometer Signal Output
4 R/B ECU Relay
6 B Ignition Signal Ground
7 G/B Receive (Control Unit Data Reception) RX
8 R/G Ignition Signal # 3
9 R/L Ignition Signal # 4
10 G/Y A/C Relay
12 P/B Automatic Transmission Gear Select
13 B Ignition Signal Ground
14 G/W Clock (Synchronization Signal) CLK
15 G Transmit (Data Sent From Control Unit) TX
16 W Mass Air Flow Sensor Signal Input
17 B Mass Air Flow Sensor Ground
18 L/O Engine Coolant Temperature Sensor Input
19 W Oxygen Sensor Input
20 W Throttle Position Sensor
21 B Sensor Ground
22 W Cam Angle Sensor 180 Degree Signal
23 G/R CLK Data Link Connector For Nissan Consult
24 / Malfunction Indicator Lamp (Add Wire For Check Engine Light)
25 O/B Exhaust Over Temp Warning Lamp Output
26 L/Y Exhaust Temperature Sensor
27 W Detonation/ Knock Sensor Input
28 W/L Automatic Transmission TPS (Kick Down Switch)
29 B Sensor Ground
30 W Cam Angle Sensor 180 Degree Signal
31 B Cam Angle Sensor 1 Degree Signal
32 Y/G Vehicle Speed Sensor
34 O Start Signal
35 G/O Park/ Neutral Position Switch
36 B/R Ignition Switch
37 Lg/R Throttle Position Sensor Power Output
38 B/W ECU Power
39 B ECU Ground
40 B Cam Angle Sensor 1 Degree Signal
41 L/G A/C ON Switch
42 Br/Y Automatic Transmission Gear Select
43 Pu/W Power Steering Oil Pressure Switch (Helps Idle When Turning Wheels)
44 Lg/R Automatic Transmission Gear Select
45 L/W Intake Air Temperature Sensor
46 R ECU Backup Power
47 B/W ECU Power
48 B ECU Ground

QUESTION!!! Just noticed my Sr harness doesn't match this pinout. I went to check the coil packs 3 and 4, and I don't even have a wire in pin 8. I have a green with red stripe in 9, nothing in 10, a green with yellow in 11, nothing in 12, and 13 and 14 match the pinout. What the fuck does that mean and what kind of harness is this? It plugs into the computer, as well as all the connections on the motor!

03-22-2012, 01:34 PM
According to this http://www.midweststreets.com/240SX/ecupin/S13-ECUPinoutS-13Blacktop.xls, I have a blacktop harness, which pisses me right the fuck off because I bought it from a member on here who told me it was for a redtop. Is this fixable by changing a few wires or what? Motherfucker.

03-22-2012, 02:08 PM
Just went through comparing the blacktop harness vs the redtop ECU; there are 12 MAJOR differences in the pinout locations. The ONLY coil pack that lines up correctly is #1! This answers the question to about 30 unanswered threads on the Internet that I've found thus far. Glad to be the one to figure this out. Hopefully it helps someone in the future.

03-22-2012, 04:53 PM
Is coilpack harness grounded?
And the grounds of engine good?