so i figured my fuel pump was going out because it felt like my truck would loose power at steady throttle and under acceleration when i would first start it up. so today i replace the fuel pump w/ an oem unit. everything seemed to go ok w/ the removal and install, but when i first started it up, i gave it some throttle and the rpms wouldnt drop like they should. it would hang up at 1500rpms and then at 1000rpms before going back to idle. so i disconnected the battery again and reconnected it to see if that would make any change. it did, but for the worst. it almost doesnt want to idle at all now. it just barely bounces at 400rpms and the truck wants to die. any thoughts on what i did wrong? its a 05crewcab 1/2ton w/ a 5.3. i'm thinking about driving it around this weekend w/out the bed until i can figure out the problem.

 

have a code scanner check see what codes come up and also ridiculous question but when was the last time you changed the fuel filter?

 

I have had a similar problem after disconnecting my battery. It just needs to learn to idle again. I just started it and let it idle for 15 minutes and it came back to normal. Give that a try.

 

Try cleaining the Throttle body opening, the Blade, IAC Valve and its passage, and also the mass Air flow sensor.... BTW if you haven't done it a fuel filter is also recomended.

FWIW IAC Valve is short for Idle Air Control Valve

 

Just like neverdone mentioned, it must have had to relearn how to idle correctly or something. It idles fine now. But I do still notice a hesitation like before , but not so harshly like it was w/ the old pump. I've never changed the fuel filter and the idiot I am, I didn't think to get a new one to throw on. For some reason I thought there would be a new one attached to the new pump. Looks like i'll be pulling the bed again this week to replace that now too.

 

The one on the pump is a pre filter to keep debry from entering the pump. There is also an inline filter along the frame rail. Thats the one you should replace. No need to pull the bed for the inline filter. There around $10 deppending on the brand you buy only takes about 10 min to change. Just be carefull with the little O-rings

 

BTW a little note about the inline filter along the frame rail, its recomended to be changed every 30k miles.

 

So even on an 05 there is an inline filter along the frame rail? I thought they moved fuel filter into the take in 04?

 

um you got me there... I forgot they went from a return style to a return less style Fuel system... I don't have access to one that new. You might be right...

 

I had the same problem last week when I swapped TB's. I disconnected the battery and had to let the truck relearn itself. After that it was all hunky dorey! I also swapped the fuel pump on a friends truck 2 days ago...two of us had trouble getting the bed off by ourselves...you do it on your own? how'd you do it?