I'm new to this site and owning a Chevrolet so pls all, bear with me.

I have an 07 LT3 with the 5.3 Flex fuel. I was doing some work on it and changed plugs and cleaned the TB unit. I also power washed the undercarriage and cleaned the radiator fins. Now, when the truck is idling and I stomp on it or rev the engine, the engine will kind of hang at or around 2000rpm for a couple of seconds before it goes back to a normal idle of around 800rpm.

I cleaned the TB by stuffing a rag inside and spraying carb/throttle body cleaner down the throat and wiping the sides down with another clean cloth and yes, I did pull the rag back out..

As I said I am new to GM products so I am wondering about this. Is the ECU learning or relearning since some things have changed, has something failed? No codes have been thrown so far? I have looked and looked for something out of the ordinary.

Any idea's or suggestions???

 

Sometime after cleaning the throttle body with cleaner, it makes things clean and dry, the shaft will stick or be slow returning. You might want to try spraying some WD40 on the throttle slides on the inside of the throat, both sides to make sure it is well lubricated.

 

magician: Welcome to the forum

Since the throttle is not mechanically connected to the accelerator pedal, what Twincycles says makes a lot of sense.

 

Twinncycles idea does make sense to me. I didnt think of that.
I did talk to a friend who is a chevy maniac and he said it may be that since I manually moved the TB butterfly to open I could have confused or mixed up the signals going to both of the TPS's?? In any case I'll be looking at the ecu on HP Tuners today and will try the WD40 thing as well to see if that helps?

More to follow.

 

I have been using cleaner with a tooth brush for years to clean the throttle throats, and after clean up, go back with WD40 and have never had an issue on all vechicle types.

Let us know how you it turns out.

 

Okay, so far everything is fine except, the O2 sensors are lazy on this truck. Not too surprizing since it has 118K on the odometer. What is surprizing is how lean the ecu has this truck running and how much spark knock I am getting? I dont know alot about the O2 sensors but I suppose the fact that they are lazy(slow to react) could have something to do with it? I will try changing the sensors and see what that does?
The HP Tuner program tells a complete story as far as what the truck is doing but its not to open with suggestions to make the right repairs. Does anyone here think I'm doing the right thing replacing the sensors and then see what Ive got?? Is there a better idea out there??

 

118K, I think it is very plausible that the O2 sensors could be tired....

only thing I would consider is using a dry lubricant on the throttle plate/linkage as the oil suspension of the WD40 could hold dirt particles and may require more regular cleaning... annual cleaning with a carb/choke cleaner may be sufficient as the linkage for the most part is designed to operate dry.. my .2¢

 

Thats my plan for now to change the O2 sensors then start on the tranny and do all the fluids on the truck. I'm also working on a noise in the rear suspension, specifically in the rear brake hub/axel area....With the Holidays and familiy around it might be awhile tilll I get there though..

Thanks for all the good ideas.