I have recently replaced dummy plugs and stc fitting and still no start when hot. Its an 05 6.0 it has egr delete, sct tuner. Any help wouldbe helpful

 

An air test is the only way to find a High Pressure Oil leak, may be a top injector oring or the oring for the nipple in the oil rail

 

Not trying to hijack the thread but im having a similar issue. Several times now ive pulled in to get fuel, shut off the truck, fill up and when i go to start it again it wont. Usually has to sit for 5-10 mins before it will start again.

I replaced standpipes, dummy plugs and stc as well. Also having an issue with really cold starts. It quite often will only fire up on 5-6 cylinders on really cold days. Itll sit and chug away till the high idle kicks in and then it usually goes away within a couple mins.