Have you swapped spark plugs between cyl 1 and another cyl?
Is pipe feed to cyl 1 kinked or a different length?
Is spud for cyl 1 in a different position on the runner for cyl 1 compared to other cyls (your manifold drill position point)?
If you swap injector positions between cyl1 and another cylinder, does the misfire move with the injector? Edit - I remembered you've tried this.
Under what conditions does the misfire occur (OBD2 freeze frame data might help pinpoint)? If misfire is with increasing rpm from 3000+ with quite a lot of throttle it may be due to the jump in numbers on your map between those conditions.
Thanks for the offer of the injectors, gratefully accepted! I have boxes full of old bits, never know when they might come in handy for effecting repairs where customer prefers to use second hand bits rather than fit new (keeping costs down).
Reckon there are those who think the forum might be frequented more by other pros if I didn't write as informed and thorough replies
Full time LPG installer
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