Originally posted by davllwilliams
Could it be fuel injector out of spec?
I would suspect a dirty injector over one out of spec.
How does excessive valve clearance create higher compression? Does the extra clearance bring more air into the cylinder? Is it only on the inlet valves because I can't see how it would do it on the exhaust manifold. What are the valve clearances?
Valve clearances that are too loose will eliminate some overlap, but that would mean more trapped exhaust gasses more than an increase in effective CR.
Clearances differ for different engines, but I believe most Hondas stay happy with about .007" IN, .009" EX.
This could explain the erratic behaviour because the high compression detonates the fuel.
If it's been a while since your last valve adjustment, go ahead and try that first.
Thanks again and sorry about the 20 questions
That's what we're here for.