The CP4 pump issues are best addressed with CONTINUOUS addition of injector cleaners and especially lubricity additives. I don’t say this to try to upsell product but rather to directly address the problem as best we’re able. Cleanliness and slip are key, and we offer two diesel products that are particularly well-suited for such applications.

Berryman DIESEL INJECTOR CLEANER (part #0518) has great lubricity and our highest amount of injector detergency. Our DIESEL CETANE BOOSTER (part #0517) offers great detergency and injector cleaning and is particularly good in colder weather when startups can be difficult. Both products are conveniently offered on Amazon and have stellar ratings.

Hope this helps. Let us know if you have any additional questions.