KA24DE
Their are a few versions of the Nissan KA24DE, but we will be focusing on the 1991 - 1994 Nissan 240SX version in this article.
Most of this information can be applied to the S14 KA24DE variant as well.
These engines are often swapped out in favor of one of the SR20DET engines that Japan got in the 240sx, and while those are
great engines, the KA24DE can be as well with a little love and support. Sporting a cast iron block and cam on bucket design,
it is already in a better spot than the SR as far as strength and reliability goes.
Just add a turbo and enjoy this old Nissan truck engine!
Haltech ECU Options
You can use several Haltech ECU options for the KA24DE depending on the features and functions you want from your project.
I will go over a few below.
Elite 550:This is the most entry level ECU you can wire up to your KA24DE. It is packed full of features and a great
place to start with any budget build.
Elite 1000: This is a perfect ECU for a street car that wants a bit more control than the Elite 550 can offer, but not
the race features of the Elite 1500.
Elite 1500: This is the most advanced 4 cylinder ECU we offer. It is designed for race applications where you need
all the advanced features you can get!
We do offer some PnP options as well for the KA24DE found in the 91-94 240SX.
- HT-150853 Elite 1000 kit
- HT-150955 Elite 1500 kit
These are listed for the S14 version 2 and S15 240sx, but also plug into the KA24DE.
We also offer a base map for the KA24DE when using these kits.
It will be linked below in this article.
General Information
| Cylinders | 4 |
| Displacement | 2389cc |
| Firing Order | 1,3,4,2 |
| Cylinder Orientation | Cyl1 front, Cyl4 rear |
Sensor Information
Crank/Cam Sensor (CAS)
The KA24DE use a distributor ignition system with a integrated CAS. This system is fairly common on most 90's era Nissans and
incorporates the crank angle sensor and cam angle sensor into one unit. These CAS systems use a optical sensor and a trigger
disk located inside the distributor to let the ECU know the engines position. This disk has 360 slits in the outer ring and 4 slits
in the inner ring. Nissan calls the 360x signal a "1 degree" and the 4x signal a "180-degree". Interestingly the 1 degree signal has
360 slits for 720 crank degrees.
| Pin | Description | Haltech Connection |
| 1 | Signal Ground | Signal Ground (Blue in Trigger 4-core) |
| 2 | 12V+ Switched | 12V+ (Red in Trigger 4-core) |
| 3 | 360x (Home+) | Home+ (Yellow in Home 4-core) |
| 4 | 4x (Trigger+) | Trigger+ (Yellow in Trigger 4-core) |
Trigger/Home Wiring Hack
For applications where there is a dual Hall Effect pickup in a CAS or Distributor there is a quick wiring hack that
allows the Home+ signal to be incorporated in the Trigger 4-core shielded cable. This can make the wiring much cleaner and easier.
To do this we will be relocated the wiring at the ECU Connector so that the unused Trigger- wire is instead placed
onto the ECU pin for Home+. This means that the Trigger 4-core cable now has 12V+, Ground, Trigger+ and Home+
all in the one cable. The GREEN wire that is labelled at Trigger- is now actually the Home+.
For Elite 550/750/950 models
1. Unplug the Main Connector at the ECU end.
2. Unlock the connector by pushing in the large white tab on the connector until it clicks. This will cause
the two smaller white tabs to pop up on the other side.
3. Remove the Yellow Home+ wire from pin 32. Insulate this wire, it will not be used.
4. Remove the Green Trigger- wire from pin 33 and move it to pin 32. Push it all the way until you can
see the metal pin clearly from the pin side of the connector and it looks the same as all other pins.
5. Lock the connector by pushing back down the 2x white tabs until they click into position.
For Elite 1000/1500/2000/2500 models
1. Unplug the smaller 26-pin Main Connector at the ECU end.
2. Unlock the connector by pushing in the large white tab on the connector until it clicks. This will cause
the two smaller white tabs to pop up on the other side.
3. Remove the Yellow Home+ wire from pin 2.
4. Remove the Green Trigger- wire that is in pin 5 and move it to pin2. Push it all the way until you can see
the metal pin clearly from the pin side of the connector and it looks the same as all other pins.
5. Lock the 26-pin connector by pushing back down the 2x white tabs until they click into position.
1. Unplug the smaller 26-pin Main Connector at the ECU end.
2. Unlock the connector by pushing in the large white tab on the connector until it clicks. This will cause
the two smaller white tabs to pop up on the other side.
Trigger Configuration
Ignition Coils
There is a single coil on the KA24DE engines.
This fires spark to the distributor and that distributes it to the correct cylinder based on engine angle.
The coil has a 2 pin plug, one wire is switched 12v (black and red) the other is the trigger from the ignitor (green and black)
Since the OEM coil is a dumb coil (no internal ignitor) you need to have a external one. It is usually bolted to the coil bracket like above.
1- Signal from ignitor to coil
2- Ground to cylinder head or coil mounting bracket
3- Signal from ECU to ignitor
You can install individual coils and trigger them from the Haltech as well.
The is the recommended method for higher HP cars since it gives you better spark energy, and the ability to control each
cylinder individually if needed. You just need to get your individual coils mounted and wire cylinders 1, 2, 3, and 4 to
their matching ignition output on the Haltech ECU.
Cylinder 1 goes to ignition 1
Cylinder 2 goes to ignition 2
Cylinder 3 goes to ignition 3
Cylinder 4 goes to ignition 4
After you have it wired, you just need to tell the ECU that you are using coil on plug instead of the distributor.
This change can be done in the main setup menu.
Just select "Direct Fire" instead of "Distributor"
Dwell
Suggested dwell time for stock Nissan KA24DE coil
Throttle Position Sensor
The throttle position sensor is mounted to the throttle body with a little pigtail to the connector.
| Pin | Description |
| 1 | 5V+ |
| 2 | Signal |
| 3 | Signal Ground |
MAP Sensor
These engines do not come with a MAP sensor. Use the internal MAP sensor that comes with your ECU.
For higher boost levels an external MAP sensor should be used instead.
Idle Valve
KA24DE engines come with a 2x separate 2-pin BAC idle valves.
These only require a 12V+ power source that is switched with ignition power, and any spare ECU output, like a DPO.
Only the larger solenoid is connected to the ECU, and this is a duty pulsed type solenoid where more duty opens the
valve to give a higher idle speed. The smaller solenoid is a switched type that is used anytime the A/C clutch is engaged.
This is not wired or controlled by the ECU.
Solenoids are not polarity dependent
| Pin | Haltech Connection |
| A | 12V+ Switched |
| B | Any spare DPO output |
Coolant Temperature Sensor
There are 2 on the S13 KA24DE, a single wire that goes to the dash coolant temp gauge, and a 2 wire plug that is for the ECU.
We only need the 2 wire one for the ECU. One is any available AVI with a pull up, and the other is a signal ground.
Wiring is not polarity sensitive on this sensor.
Calibration: Use "Temperature - Nissan S15 Coolant.cal"
Air Temperature Sensor
KA24DE's do have a OEM air intake temp sensor in the OEM air box, but most are damaged or missing due to the age of the engine.
The Haltech still needs one to work and the PnP kits we offer come with one so you do not need to purchase one if you have that kit.
If you are just purchasing the ECU, you will need to get one to wire to the Haltech.
I recommend our 1/8 NPT sensor for this.
Haltech 1/8" NPT Air Temp Sensor
You will use any open AVI with a 5v pull up and a signal ground. Polarity does not matter with this sensor.
Calibration: Use "Temperature - Haltech 1/8 NPT HT010304.cal"
Knock Sensor
OEM Knock sensors are polarity dependent.
They also internally link the ground to the engine block which is bad for signal ground integrity and it is recommended to exchange
the sensor for a Haltech unit. In the Nissan wiring there is no connection to pin 1.
| Pin | Haltech Connection |
| 1 | No Connection |
| 2 | Signal (Knock 1) |
MAF Sensor
Although most users of Haltech ECUs will be deleting the MAF, it is possible to use a MAF if you prefer.
S13 KA24DE MAF
Pin letters are written on the sensor
| Pin | Description |
| 1 | Signal 0-5V |
| 2 | Sensor Ground |
| 3 | 12v switched power |
OEM ECU Information
S13 KA24DE
Base Maps
Base maps have been created for use with the Haltech Elite Adapter Harnesses and these are included in the ESP Software package.
It will be attached below as well.
To use these maps they should be IMPORTED into your ECU. Follow the IMPORTING A BASE MAP guide.
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