KA on three cylinders - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

AKADriver · 03-11-2024, 09:13 AM

Just looking for confirmation on my diagnostic thinking.

Drove my car about three hours yesterday without incident. Stopped at a grocery store for 30 minutes, restarted, struggling to idle. Cylinder #3 was clearly dead (verified by pulling the plug wires one by one). Limped it home 15 minutes away, it never "kicked back in".

No smell of gas or smoke from the exhaust, and confirmed #3 is getting strong spark. I think #3 is getting no fuel.

I happened to find an injector noid that some previous mechanic lost down in the vacuum/water line nest under the intake runners while pulling the engine last time, so I tried that on the #3 injector pigtail and it didn't light up. That said, the noid might be bad; I haven't had the time to try it on a different cylinder that I know is firing. I'm going to do that first.

If the noid says #3 is getting no injector pulse, I think my next step is to check continuity from the ECU to the injector harness connector? My engine harness has a lot of crusty looking connectors, peeling tape, crumbling loom, etc. and this may be a sign to make that order to Wiring Specialties.

Or is the ECU itself suspect? Has anyone had a single ECU injector driver fail?

03-11-2024, 09:13 AM	#1
AKADriver Post Whore! Join Date: May 2002 Location: Springfield, VA Age: 42 Posts: 3,475 Trader Rating: (1) Feedback Score: 1 reviews	KA on three cylinders Just looking for confirmation on my diagnostic thinking. Drove my car about three hours yesterday without incident. Stopped at a grocery store for 30 minutes, restarted, struggling to idle. Cylinder #3 was clearly dead (verified by pulling the plug wires one by one). Limped it home 15 minutes away, it never "kicked back in". No smell of gas or smoke from the exhaust, and confirmed #3 is getting strong spark. I think #3 is getting no fuel. I happened to find an injector noid that some previous mechanic lost down in the vacuum/water line nest under the intake runners while pulling the engine last time, so I tried that on the #3 injector pigtail and it didn't light up. That said, the noid might be bad; I haven't had the time to try it on a different cylinder that I know is firing. I'm going to do that first. If the noid says #3 is getting no injector pulse, I think my next step is to check continuity from the ECU to the injector harness connector? My engine harness has a lot of crusty looking connectors, peeling tape, crumbling loom, etc. and this may be a sign to make that order to Wiring Specialties. Or is the ECU itself suspect? Has anyone had a single ECU injector driver fail?