Need Help Yukon XL '03 5.3 Flex Fuel

[bigjoey111]

Hey guys/gals i'm stuck. My yukon has been acting weird lately and i'm not sure if its just an electrical issue or what.

Symptoms:
Hard to start, need to crank it 2-4 times before it really starts up will false start several times and sputter out.

4wd will turn on randomly on startup either goes into auto 4wd or 4hi/lo not all the times but sometimes it does and i dont realize it until i start to accelerate and feel it.

Service 4wd sometimes comes on but rarely ever does.

Rear View Mirror temp display was acting up all the time turning off and on and now it completely doesnt work.

Passenger side headlight randomly turns on and off.

If anyone has a solution i would appreciate it or any ides. I really only care about the start up issue as i can live with the rest but last week i tried starting the truck and it would not start up just turning over and over and false starting a lot then sputtering out. I changed fuel filter and that did nothing.

Thanks Joe

 

[chauncey0337]

Sounds like you have some weird electrical gremlins. I haven't a clue. As for the startup issues, I'd try banging on the gas tank and see if it starts or get the ffuel pressure tested. Similar thing happened to me and turned out to be the fuel pump.

 

[kschumake83]

I would look into bad grounds and see if you have a short somewhere in the system. Clean the contact points on all the ground wires in the vehicle and replace any wires that seem to be badly corroded or broken. If not then remove the battery cables and see if you have continuity between the positive and negative. If you do start removing fuses until it doesn't have continuity between them and that will tell you what part of the truck to start looking for a short.

 

[jdpber]

Need to get a scan computer on it and start finding the issues. Could be as simple as a faulty sensor to needing a new ecm