Odd problem. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Thompson1990240 · 05-18-2019, 06:26 PM

So my buddy handed over a 1990 240sx with a ka24e and a 5 speed. This car is completely trashed and I’d honestly be surprised if it’d ever run again but that’s what I’m here for. Now before we get into it I’m a v8 guy. I prefer to sit down to pee. I do ls swaps into machines usually have ls engines. My initial intent was to ls swap this car but I want to get the engine running so I can sell the drivetrain to help pay for a cheaper swap.

Now to get into it:

This car had spark 2 days ago when I was reading codes and I got a 23 code- idle switch, and a 45 code: leaking injector. But while turning over it would get a little spit here and there as if it wanted to run. Of course I unplugged #2 injector because it was staying open causing the 45 code and flooding the engine. Today I replaced the tps and tried to set the idle voltage to .45-.55 as read on a recent thread and had no power to the tps even when I moved it to WOT by hand. So as a more advance hands on person I checked spark and had nothing. Keep in mind I know NOTHING about these import cars. So I went to check codes again and saw that the computer lights (red and blue LEDs) weren’t coming on with the ignition. Under further investigation the pump was staying on the entire time. I can’t seem to find a pcm Pinout for this particular car so if anyone had one that would be great. Also the location of all grounds would be spectacular aswell. And oh forgot to mention. When I went to try and start it prior to replacing the tps I noticed I had forgotten the small pigtail that seems to be a ground???? That connects to the bracket of the ignition. I also have checked for 12 volts at the main pigtail for the ignition coil and I have power. Are these controlled ground side or are they always hot with the key? And if there’s a bad ground would It make sense to be gettingpower to the coil? Let me know if any further information is needed!

***FaLKoN240*** · 05-20-2019, 11:58 AM

Approved thread. I hope you find the answer you're looking for.

foreverdeath · 05-20-2019, 04:28 PM

Its gona be hard to find that info, the FSMs for the KA24E is kinda sparce. just did a skim as they are vasatly different from the 91 and up FSM, and struggled to find anything. But fuel pump always being on is indictive of a bad ECU. If you unplug the ECU does the fuel pump stop?

Standard · 05-22-2019, 08:22 AM

There's a 1990 240sx fsm in the marketplace for $50 right now, don't sleep on it!!
https://zilvia.net/f/showthread.php?t=668965

I have a fsm for 91-94, pm me if you need any scans from it, good luck

NukeKS14 · 05-27-2019, 07:18 AM

OP,

ECU pinout for 1990 240sx go to pg 9.

1989 240sx FSM Most of the wiring shouldn't differ. I'd use the first link for the ECU pinout and this one if you want to delve into the chassis wiring.

The fuel pump relay is triggered directly from the ECU so, yeah, if it's staying on there's either a short in the wiring or issue with your ECU as said before.

The ignition coil power (black/red) wire connects to the ignition switch and at a node that also goes to the ECU (Pin 36) and draws power from the chassis connector. In short, it's going to be getting 12v when the key is on. This ECU controls using common ground/switched power to answer your other question.

When you ask about a bad ground, did you test the 12v at the coil to chassis or did you test it pin to pin between the blk/red wire and blk wire at the ign coil?

regardless, I don't think your ignition coil is the issue here.

Make sure all of your wiring at the ignition is connected and good luck with getting this figured out.

05-18-2019, 06:26 PM	#1
Thompson1990240 Join Date: May 2019 Location: Fort Worth Texas Posts: 1 Trader Rating: (0) Feedback Score: 0 reviews	Odd problem. So my buddy handed over a 1990 240sx with a ka24e and a 5 speed. This car is completely trashed and I’d honestly be surprised if it’d ever run again but that’s what I’m here for. Now before we get into it I’m a v8 guy. I prefer to sit down to pee. I do ls swaps into machines usually have ls engines. My initial intent was to ls swap this car but I want to get the engine running so I can sell the drivetrain to help pay for a cheaper swap. Now to get into it: This car had spark 2 days ago when I was reading codes and I got a 23 code- idle switch, and a 45 code: leaking injector. But while turning over it would get a little spit here and there as if it wanted to run. Of course I unplugged #2 injector because it was staying open causing the 45 code and flooding the engine. Today I replaced the tps and tried to set the idle voltage to .45-.55 as read on a recent thread and had no power to the tps even when I moved it to WOT by hand. So as a more advance hands on person I checked spark and had nothing. Keep in mind I know NOTHING about these import cars. So I went to check codes again and saw that the computer lights (red and blue LEDs) weren’t coming on with the ignition. Under further investigation the pump was staying on the entire time. I can’t seem to find a pcm Pinout for this particular car so if anyone had one that would be great. Also the location of all grounds would be spectacular aswell. And oh forgot to mention. When I went to try and start it prior to replacing the tps I noticed I had forgotten the small pigtail that seems to be a ground???? That connects to the bracket of the ignition. I also have checked for 12 volts at the main pigtail for the ignition coil and I have power. Are these controlled ground side or are they always hot with the key? And if there’s a bad ground would It make sense to be gettingpower to the coil? Let me know if any further information is needed!

05-20-2019, 11:58 AM	#2
*FaLKoN240* Super Moderator Join Date: Jun 2004 Location: SoCal Temecula Posts: 16,885 Trader Rating: (73) Feedback Score: 73 reviews	Approved thread. I hope you find the answer you're looking for. __________________ Best way to do business with me? Make your best offer FIRST.

05-20-2019, 04:28 PM	#3
foreverdeath Zilvia Junkie Join Date: Sep 2012 Location: va beach Age: 31 Posts: 321 Trader Rating: (3) Feedback Score: 3 reviews	Its gona be hard to find that info, the FSMs for the KA24E is kinda sparce. just did a skim as they are vasatly different from the 91 and up FSM, and struggled to find anything. But fuel pump always being on is indictive of a bad ECU. If you unplug the ECU does the fuel pump stop?

05-22-2019, 08:22 AM	#4
Standard Zilvia Addict Join Date: Apr 2014 Location: Milwaukee Age: 34 Posts: 815 Trader Rating: (11) Feedback Score: 11 reviews	There's a 1990 240sx fsm in the marketplace for $50 right now, don't sleep on it!! https://zilvia.net/f/showthread.php?t=668965 I have a fsm for 91-94, pm me if you need any scans from it, good luck

05-27-2019, 07:18 AM	#5
NukeKS14 Zilvia Member Join Date: Apr 2019 Location: KS Posts: 221 Trader Rating: (1) Feedback Score: 1 reviews	OP, ECU pinout for 1990 240sx go to pg 9. 1989 240sx FSM Most of the wiring shouldn't differ. I'd use the first link for the ECU pinout and this one if you want to delve into the chassis wiring. The fuel pump relay is triggered directly from the ECU so, yeah, if it's staying on there's either a short in the wiring or issue with your ECU as said before. The ignition coil power (black/red) wire connects to the ignition switch and at a node that also goes to the ECU (Pin 36) and draws power from the chassis connector. In short, it's going to be getting 12v when the key is on. This ECU controls using common ground/switched power to answer your other question. When you ask about a bad ground, did you test the 12v at the coil to chassis or did you test it pin to pin between the blk/red wire and blk wire at the ign coil? regardless, I don't think your ignition coil is the issue here. Make sure all of your wiring at the ignition is connected and good luck with getting this figured out.