Not sure about year old or even new fuel? Your fuel problems could be coming from the fuel supplier…..check the fuel before you buy it. Quick, no‑nonsense field test. Works in all diesel fuels. Test is designed as a field PASS or FAIL. Deluxe package $35.95 for one each Fuel Clarity and Bacteria/Algae Test Deluxe … Continue reading Test for Year Old Diesel Fuel Contamination Check Fuel Degradation & Stability Dieselcraft