yukon dies at idle

[Kool rider28]

ok check my fuel pressure. i also found there was a code IAC so i changed it. still the same problem. i do know when it doesnt start my injector are not spraying fuel in the tb. so im wondering what tells the injectors to spray on start-up. i spray ether and she run and i go on my way.
i really could use some help!!

 

[SunlitComet]

According to my data there is a cranking signal for enrichment of fuel applied to C9 circuit of ECM. However the diagrams show it only with a manual transmission installed maybe a typo). it is fed thru fuse #8 "crank". You can also check for injector flow by having ignition on and grounding the non-pink wire of each injector while monitoring the fuel pressure and spray pattern. There is a possibility that the injectors could be clogged to.

 

[Magnumac]

had this happen to a couple of vehicles, it was always a bad EGR valve on mine.

 

[Kool rider28]

According to my data there is a cranking signal for enrichment of fuel applied to C9 circuit of ECM. However the diagrams show it only with a manual transmission installed maybe a typo). it is fed thru fuse #8 "crank". You can also check for injector flow by having ignition on and grounding the non-pink wire of each injector while monitoring the fuel pressure and spray pattern. There is a possibility that the injectors could be clogged to.

is it possible that the module(icm) in my dizzy is bad? i read on a couple of forums that if you let your truck sit in the rain and cold weather(like i did) it will cause that module to rust

 

[SunlitComet]

It is possible bit not always because of weather. If the terminal "C-Distributor Reference Hi" output fails to work properly the ECM will loose it reference for crankshaft position and rpm. The terminal "B-Bypass" also determines based on rpm weather or not the ICM or ECM controls the timing advance.

 

[Kool rider28]

Fixed!!!!

ICM fixed it! i ran to o'reily's and got one. installed it and she fired right up! i will drive her around town tonight. i let her run for a while and killed it she started right up again.
thx for you guys support! your awesome!