LQ4 troubleshooting misfire
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Teching In
Joined: Nov 2025
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LQ4 troubleshooting misfire Just bought this car with a 2000 LQ4 6.0.
It had a lag/stumble on a fairly hard acceleration, and after a scan my knock sensors were apparently out. I replaced both, cleared codes, and reset ECU (battery disconnect).
Now I can feel it missing on low end acceleration.
Checked fuel pressure (not volume) and it was within specs.
Previous owner said he had a shop do a tune, change injectors, pump, and a coil, so at this point I have no idea what was installed. New owner of shop, with no records.
Any ideas where to start?
Thanks
It had a lag/stumble on a fairly hard acceleration, and after a scan my knock sensors were apparently out. I replaced both, cleared codes, and reset ECU (battery disconnect).
Now I can feel it missing on low end acceleration.
Checked fuel pressure (not volume) and it was within specs.
Previous owner said he had a shop do a tune, change injectors, pump, and a coil, so at this point I have no idea what was installed. New owner of shop, with no records.
Any ideas where to start?
Thanks
Last edited by Capp35; Nov 8, 2025 at 02:16 PM.
Thread Starter
Teching In
Joined: Nov 2025
Posts: 6
Likes: 0
Thread Starter
Teching In
Joined: Nov 2025
Posts: 6
Likes: 0
Borrowed my friends temp gun and one of my cylinders was 200° cooler after 3 to 4 minutes of running.
I already had an order in for new plugs and wire, so I just added a new coil to the order. Hopefully that will take care of it.
Thanks again.
