I have recently purchased an early 99 f-350 crew cab and it has a miss and is hard starting . The engine has 345000 on it and uses very little oil and has very little blowby. It had a CCT performed and 1 and 8 showed up as weak. The shop suggested that it was probably low compression, but if that was the case wouldn't there be excessive blowby? It seems like to me its running out of fuel, but I did a fuel pressure test and it never went below 58# . The problem started when the last cold snap happened (-18 below) and against my better judgement I had to put howes treatment in ( I couldn't get any 1 in. so i had no choice). About 50 miles after i dumped the howes in it started. acting up like it was gelling so i stopped and put #1 in and changed filter...it helped but the miss remainef. The shop quoted me $2400 for a compression test and 2 injectors. That's not going to happen. I have a compression tester ordered and should be here monday. It has massive white smoke. and smokes more than it should after warm up. Power is weak but not terrible. Thanks for any suggestions.