ok i am just trying to conferm somthing on my truck. ok here it is my truck in the morn has good presur at filter head but when i glow it for 10 sec it will turnover and caugh for a awhile and then it will finaly start but if i glow it for 16 sec it will hit it is taking alot of heat to start and it ant but 50 deg outside so do you think my compression is to low. i just put new beru glow plugs in and its on a manul glow switch.so i dont want to burn my glow plugs up what is the longest i can glow them without burning them up thanks for any help