Clearly this is an older thread now, but it looks like I missed the conclusion of it. Sounds like you had great service from the Denso specialist. Also it sounds like dirt may have caused wear inside the pump or possibly veg oil fuel which can sometimes lack lubricity. Anyhoo I think you had pretty good value there, as work of that nature has to be done in a surgically clean environment and involves precision parts. Well done Denso service and thanks for posting the result. Glad it’s sorted.
