Mark helpful just talked to son in law he said he changed crank sensor yesterday befor this started happening.could that have anything to do with fuel problem.
First thing,Mark Helpful is the button you click when some one answers your question and you think there help full,now on to your question,usually the crank sensor fires the fuel injectors,same as plugs,a fuel issue can be checked by check the fuel rail bleeder check valve near the heads,you should have it checked for pressure then you will know if it is a fuel issue.
hahaha- those wacky sons-in-laws-
Search GMC Yukon Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
GMC Yukon Experts