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. Test is designed as a field PASS or FAIL. Only $19.95 for one … Continue reading Test for Old Diesel Fuel Contamination Check Fuel Degradation & Stability Dieselcraft