Hello,
Is the engine misfiring at idle or under load? Is the misfire constant or intermitted?
How to check for misfire.
https://www.2carpros.com/articles/engine-misfires-or-runs-rough
When doing a CAN scan what fault codes are set?
How to do a CAN scan.
https://www.2carpros.com/articles/can-scan-controller-area-network-easy
Why was the head gasket replaced?
When you replaced the head gasket were the valves and rocker arms checked?
Have you checked the compression?
How to check compression.
https://www.2carpros.com/articles/how-to-test-engine-compression
and
https://youtu.be/J3j85hg0d-4
Symptoms and causes for low compression.
https://www.2carpros.com/articles/symptoms-of-low-compression
and
https://www.2carpros.com/articles/the-reasons-for-low-compression
The fuel injectors can be tested by using a suitable scan tool and fuel pressure tester and carrying out an injector balance test. Alternatively, injector testers and fuel pressure gauges can be purchased online, see images below. No expensive diagnostic tool is required.
See a good video.
https://youtu.be/I2IgGenAX0Q
and
https://youtu.be/QuknZ7KYBqs
Please let us know how you get along.
Cheers, Boris
Images (Click to enlarge)
Apr 22, 2022 at 8:34 AM
