Maybe a stupid question?

[soon2bfast]

I am new to the site and I just wanna say that I love the site. Anyways enough @$$ kissing. I have a 1999 ecsb GMC sierra 5.3 and when i start it up it idles fine, but after it runs for a while and I put it in gear it idles down to where it almost dies then the idle levels out. I replaced the fuel filter and found out that it had water in it, this led to me having to replace the fuel pump b/c it starting making a loud whining noise and performance was sluggish. After the pump was replaced the noise has went away, but the truck still has the idle problem. I was just wondering if anyone has experienced this problem and what the solution could be. Any help would be much appreciated.

[honkydaddy]

Have you cleaned the throttle body and the IAC passages.Gm makes some top engine cleaner you might want to run through a vacuum port as close to the T/B as possible.

[soon2bfast]

I have cleaned the tb, but I haven't run any of the engine cleaner through it i'll try some of that and see if runs better then. Thanks for the reply

[honkydaddy]

Did you clean the IAC motor out.They get dirty and make them idle rough,up and down.Should be a hole in the T/B on either side of the butterfly.You can spray some carb cleaner in it and let it soak and spray it and let it soak and spray it and let it soak until it comes out clean on the back side of the butterfly.Run some through the PCV hose too,they suck up a bunch of crud.