began having trouble starting recently,thought it might be fuel shutoff solenoid on pump as it was intermentet problem. now i have discovered that using the block heater helps, so i checked glow plugs and all are bad. could the qos controller have caused this or is it common for all plugs to go at the same time. thanks dan

not at all uncommon
WHAT USUALLY HAPPENS , WHEN ONE GLOW PLUG GOES OUT, THE AVAILABLE VOLTAGE IN THE CIRCUIT FOR THE GLOW PLUGS WILL RISE , APPLYING MORE VOLTAGE TO THE REMAINING PLUGS , AND THEY WILL OVER HEAT SINCE THE CURRENT GOES UP, THEN THE NEXT WEEKEST ONE IN LINE WILL GO OUT AND SO ON UNTILL THEY ARE ALL DEAD , USUALLY IN ABOUT 45 SECONDS OF HEAT TIME , THOSE GLOW PLUGS CAN DRAW AS MUCH AS 40 AMPS WHEN HEATINGS , YOU ARE NEVER SUPPOSSED TO REPLACE ONE INDIVIDUAL PLUG AT A TIME ,ALL WAYS REPLACE ALL 4 , AND CLEAN THE HOLE IN THE HEAD OF ALL CARBON BUILDUP WHERE THE TIP OF THE PLUG GOES UP IN THE HEAD , THIS WILL KEEP THE PLUGS FROM OVERHEATING AND ALLSO MAKE THE ENG START FASTER ALLSO BE CERTAIN THAT THE GLOW PLUGS ARE THE CORRECT TYPE , JERRY

thanks for the info jerry,I did not want to fry a set of glow plugs if i had another problem. thanks again dan