just started recently, truck SOMETIMES, intermittently, has prolonged crank. usually 2 cranks or so and it fires. the few times it's done it maybe double that, total of 3-4 seconds cranking time. one of those things it's not terrible, but I know my truck and what's normal for it. no CEL. sometimes idle has been "rough", by that I mean it fluctuates based on what I can hear. idle is sometimes just above 500, sometimes about 1000. truck has front timing cover done in November 2017 and ever since that the high idle presented itself, maybe due to colder temps too, not sure?!

did some reading and surfaced some stuff about ECT and IAC tied together and possibly cause prolonged start. there's 2 ECT sensors I saw, one on top of the manifold basically, and the other slightly below it further down the front of the engine. any way to test the ECT sensors, or IAC? I have a scanner I could get in and check things, but where would you guys suggest starting with this?

again truck has always started, prolonged start (3-4 seconds crank) is intermittent, no CEL.

 

any codes? i assume not? iac check is easy, just unplug it,if it stalls or idle drops dramatically that is good, no change in idle is bad iac or big vacuum leak