owner of 03 gmc 1500 4.8

03kcsgmc · July 25, 2014

Hello I'm new here! I've been trying to figure out why my truck starts just fine then after a few secs it starts to idle down and run rough but not die! but if I feather the throttle thru it for a few secs it smooth's back out then seems to be fine until I shut it off then when I start it up again then it repeats this!

03kcsgmc · July 25, 2014

I have replaced the fuel filter plugs, wires, cleaned MAF and cleaned throttle body! still same thing!

03kcsgmc · July 25, 2014

any takers out there? don't want to take to shop if I don't have too!

8.1HD/ALLISON · July 25, 2014

Check fuel pressure. Clean iac. Those are first 2 I would do.

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03kcsgmc · July 26, 2014

hey thanks! ill check fuel pressure tomorrow! iac is built into the throttle body right? I cleaned throttle body! but ill see what kind of fuel pressure I got hen go from there!

8.1HD/ALLISON · July 26, 2014

Yeah i believe itis built in. Keep forgetting everything is fly by wire now.

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txab · July 26, 2014

Check intake gaskets for leaks

gmtech4 · July 26, 2014

scan for codes for giggles

03kcsgmc · July 27, 2014

Check intake gaskets for leaks

what is the easiest or best way to check intake gaskets?

03kcsgmc · July 27, 2014

_I

_{scan for codes for giggles}

_{no CEL on at this time but it did flash a few times the other day during the rough idle! ill have it scanned tomorrow!}

_{thanks for you input it much appreciated.}

03kcsgmc · July 27, 2014

i did put some sea foam in a couple days ago and gas up where i normally don't and it seemed to run so much better the first half of today so i thought cool may this done the trick! so when i gas up again today i bought gas where i normally do and it started running like shit again. could it be bad gas cause i always buy my gas there?