Rough idle - changed many parts already

[cjallen1]

Hello everyone !

 

OK, here's my story:

I've got a 01 Tahoe with the 5.3L engine.

 

1. SES light came on - followed closely by some rough idle.

2. Diagnostics showed P1404 code.

3. Changed EGR valve (probably should have just cleaned it).

4. SES light went out - rough idle remained.

5. Took it to a shop to have them diagnose the problem. They said bad fuel pump.

6. I changed out the fuel pump myself (probably should have just started with

the filter).

7. Rough idle remains. Ugh!

 

I'm wondering what I need to do next. All suggestions are greatly appreciated! Please note: rough idle seems to occur mostly when in drive, stuck at a stop light (foot on the brake).

 

 

~ Signed, Disgruntled Tahoe owner

[Chad H]

You could try running some good injector, changing spark plugs, plug wires, and possibly a new air filter.

[sflichel]

Check your vacuum lines for any leaks

[larry arizona]

The 5.3 has had some issues with leaky intake gaskets causing rough idle.

 

Not a big deal to change is you had to.....

[Bish]

Mine starts to idle rough when the IAC (Idle Air Control) gets dirty. The IAC is installed in the Throttle Body. along with the above suggestions, I would pull your throttle body and completely clean it with throttle body safe cleaner. Mine was filthy at 75K and it immediately smoothed out the idle. I clean it every 30-40K.

[frupp]

How many bolts/nuts or screws are used to mount the throttle body? I have a 2000 Suburban LT 5.3L and only was able to find one nut at the top of the throttle body to remove. I felt around under the throttle body for another one or two but couldn't find anything, and I could not get the throttle body to come off. What did I miss?

 

Thanks, Frank

[Bish]

How many bolts/nuts or screws are used to mount the throttle body? I have a 2000 Suburban LT 5.3L and only was able to find one nut at the top of the throttle body to remove. I felt around under the throttle body for another one or two but couldn't find anything, and I could not get the throttle body to come off. What did I miss?

 

Thanks, Frank

 

<{POST_SNAPBACK}>

 

 

 

I believe there are three but it has been a while since I did it. When I get home, I'll check my Helms manual and post if the answer isn't posted.

[frupp]

Thanks,

Frank

[Chad H]

How many bolts/nuts or screws are used to mount the throttle body? I have a 2000 Suburban LT 5.3L and only was able to find one nut at the top of the throttle body to remove. I felt around under the throttle body for another one or two but couldn't find anything, and I could not get the throttle body to come off. What did I miss?

 

Thanks, Frank

 

<{POST_SNAPBACK}>

 

 

There is three. One at the top and two at the each lower corner.

[frupp]

Thanks, Chad. I look more closely this time.

Frank

[cjallen1]

Mine starts to idle rough when the IAC (Idle Air Control) gets dirty.  The IAC is installed in the Throttle Body.  along with the above suggestions, I would pull your throttle body and completely clean it with throttle body safe cleaner.  Mine was filthy at 75K and it immediately smoothed out the idle.  I clean it every 30-40K.

 

<{POST_SNAPBACK}>

 

 

 

 

 

Thanks for the advice! I'll try and get the throttle body cleaned in the next couple of days. I'll send another post if this fixes it.