Not sure about old or even new fuel? Your fuel problems could be coming from the fuel supplier…..check the fuel before you buy it. Diesel Fuel Water Content & Fuel Clarity Test #FCT-100 Will work for clear and with red dyed fuel. Only $19.95 for one FCT-100 Fuel Clarity Test or $89.95 for one reusable … Continue reading Test for Old Diesel Fuel Contamination Check Fuel Degradation & Stability Dieselcraft