2000 silverado 5.3

[5.3silverado]

My truck just started to do this, it idles at 1000 rpm. What causes this to happen?

 

[OldCracker29]

It could be the TPS or the IAC sensors, or a vacuum leak.

 

[5.3silverado]

1 other thing I forgot to mention is the truck seems to surge when going 55 mph. I just did plugs wires and fuel filter and new fuel pump. No check engine light either. Where do I start to look for vacuum leak?

 

[Kennyray]

1 other thing I forgot to mention is the truck seems to surge when going 55 mph. I just did plugs wires and fuel filter and new fuel pump. No check engine light either. Where do I start to look for vacuum leak?

Use some brake cleaner and spray all your vacuum lines and connections with the motor idling. Spray your intake mounting surfaces as well. Any change in rpm will indicate where the leak is.