1989 Nissan 240SX Repair Question
Nissan 240SX Sensor Problem
start with a compression test
24,854 answers provided
Did you check for trouble codes?
I did a compression test. All cylinders are around 150psi.
I checked the trouble codes in all 5 modes after replacing the idle control valve and mass air flow sensor which I knew were bad. (busted).
It said there was a malfunction in the ECCS and that it was burning rich.
Cylinders 2 and 3 spark plugs were gunked up and they are new.
If I unplug the injector wires going to cyl 2 and 3, the car will rev up but chokes down when trying to rev up with the wires connected.
I have already reversed the injectors 1 with 2 and 3 with 4. The problem did not follow the injectors.
Does this mean the ECU is bad? Is that what controls injector timing? Are the injectors being told to open to far?
I havent had much luck finding out what the ECCS is. Online it said it was behind the throttle body an top of the intake manifold... and that just isnt so.
Ever heard of such a problem?! Any help would be appreciated. I'm at a loss here.
ECCS - Electronic Concentrated Control System is not a component. It the system named by Nissan for their fuel injection system used in this vehicle.
What are the trouble codes you are getting now after parts replacement?
well, in mode ONE the red light is illuminated which indicates an ECCS malfunction.
Then in mode TWO the red light is off which indicates it is running rich.
In Mode THREE I have 5 reds and 5 greens which means no fault.
So, what is making it run so ragged above an idle. and why does it run better at a fast rpm with injectors 2 and 3 unplugged?
Your code retrieval does not match what I have in our database. Here they are. Let me know if they are what you have done.
1. Turn ignition switch to "ON" position. Use a screwdriver to turn ECU diagnostic mode selector fully clockwise.
2. Wait for inspection lights to begin flashing. At this time, inspection lights will flash the mode options (i.e. 2 flashes for Mode 2, etc.). As soon as inspection light flashes the desired mode number (3 flashes for Mode 3), immediately turn mode selector off.
3. If the mode selector is kept in the "ON" position, the mode selections will
continuously cycle (Mode 1 to Mode 2 up to Mode 5, then cycles to Mode 1, etc.) and the process will continue. This will not erase the memory.
NOTE: Mode 3 is used to retrieve trouble code(s) from the ECU self-diagnostic system.
Trouble codes are read using the Red and Green LED inspection lights on the side of
the ECU. After selecting mode 3, trouble codes corresponding to that mode will start
flashing. Trouble codes are indicated by the number of flashes from the ECU Red and
Green LED inspection lights. Count the number of flashes. The Red LED indicates the
number of tens while the Green LED indicates the number of ones. For example, 3
flashes of the Red LED followed by 2 flashes of the Green LED would indicate code
Yes, that is exactly what I have done. In mode THREE I get five red flashes and 5 green flashes. This is supposed to represent no faults found. But there is definately a problem.
Code 55 means no faults have been detected in the ECCS and the problem is not likely to be sensor or circuit faults.
You have a problem which is more likely to be mechanical or maybe the ECU itself.
Check the spark plug wire. Have them ohmed out and ensure the firing order is correct, 2 and 3 could have been swapped.
I replaced the wires already. but my nephew put plugs in it. It is possible he swapped the wires. Do you know the firing order? BTW Thank you for what y'all do. You seem to really want to help people and you don't see much of that anymore.
Firing order is 1-3-4-2, counter-clockwise from top of distributor cap.
We at 2carpros here are always willing to help and would always give it our best shot and I never like to give up until I come to a conclusion. It is my love of helping others and solving problems that keeps me here.
There are many people out there willing to give a helping hand but at times helping others physically can be dangerous as we have cases of rigged accidents etc to rob. Working online we don't have that worry.
Lets hope coming back to basics solves our problem, just some swapped wires, lol