My 1991 240sx has been having intermittent starting issues since I got it, the most recent part culprit was the maf but once again it stopped running.
Info:
-Codes 11 and 21
-Fuel Pressure at 38 psi when primed
-Injectors don’t click when cas is turned by hand
-Cas has ground and power
-Replaced distributor less than a year ago
-No continuity from cas to ecu (not 100% sure I tested right)
-Fuel pressure changes when cas is disconnected
Based on this I think it’s the wiring to the ecu but I wanted to know if there is anything else I should check.
Crank No Start (No Spark or Fuel)
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cesar70899
- Posts: 1
- Joined: Wed Jan 04, 2023 10:03 pm
- Car: 1991 Nissan 240SX
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NukeKS14
- Posts: 310
- Joined: Wed Apr 10, 2019 2:50 pm
- Car: 1995 240SX SE - KA24DE-T
AC Cobra Mk IV Rep.
2020 Civic Si
Re: Crank No Start (No Spark or Fuel)
could be the signal wire from the CAS to the ECU. I had broken wire in one of my early S13's that would periodically make connection and the car would run just fine, then out of the blue I'd go over a speed bump or hit a pot hole and it'd completely cut out.
Are you getting spark? If no spark and no fuel it's something between the ECU and CAS and my bet would be on the wiring.
https://www.nicoclub.com/service-manual ... _240sx.pdf
according to the FSM hosted here, EF & EC 100, you should be checking continuity between the white pin at the CAS and 22/30 at the ECU. Black - 31/40
The left side shows the ECU connector from both sides, front and back (front would be the side that connects to the ECU)
The right way to check continuity of the signal wire between the CAS and ECU is to disconnect the battery negative terminal (dont want to short anything out with the ECU) remove the ECU, then use a digital multimeter (DMM) set to resistance and check for continuity (on Ohms) between the pin at the ECU and opposite end at the distributor plug. You should get very low resistance if it's good. If it's OL (overload) or very high it's broken or not making connection. It helps to have a second pair of hands to hold one end in the engine bay and watch the DMM while you move the harness around with your hands. You should be able to find the break in the wire if that's what the cause is.
Those old wiring harnesses get pretty brittle and the smallest nicks in the insulation can lead to oxidation and issues with them. Good luck wiring gremlins can be a real pain.
Are you getting spark? If no spark and no fuel it's something between the ECU and CAS and my bet would be on the wiring.
https://www.nicoclub.com/service-manual ... _240sx.pdf
according to the FSM hosted here, EF & EC 100, you should be checking continuity between the white pin at the CAS and 22/30 at the ECU. Black - 31/40
The left side shows the ECU connector from both sides, front and back (front would be the side that connects to the ECU)
The right way to check continuity of the signal wire between the CAS and ECU is to disconnect the battery negative terminal (dont want to short anything out with the ECU) remove the ECU, then use a digital multimeter (DMM) set to resistance and check for continuity (on Ohms) between the pin at the ECU and opposite end at the distributor plug. You should get very low resistance if it's good. If it's OL (overload) or very high it's broken or not making connection. It helps to have a second pair of hands to hold one end in the engine bay and watch the DMM while you move the harness around with your hands. You should be able to find the break in the wire if that's what the cause is.
Those old wiring harnesses get pretty brittle and the smallest nicks in the insulation can lead to oxidation and issues with them. Good luck wiring gremlins can be a real pain.
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