Idling issues

[Lit549]

2005 tahoe 5.3))I posted awhile back with issues with the truck wanting to die or idle real low when I come to a stop.. General advice was clean throttle body and do a reset, well that doesn't work anymore.. When I come to a stop the engine goes down to around 300rpm and stays there most times, sometimes it doesn't do it.. 7 out of 10 times it does it..I need a new throttle body??

 

[OR VietVet]

So, you are saying cleaning the throttle body and the reset did fix the problem for a while? If I replied to your original post, which by the way you should have tagged this current info on to that thread, I would have also said to clean the Mass Air Flow Sensor with a cleaning kit from a parts store. Follow the directions. Did you do that too?


Everything else may be fine and you have an intermittent problem with the TPS.

 

[Doubeleive]

how many miles?

 

[OneofFew]

wouldnt this be a classic symptom of a failing IAC valve? You could clean it and get more life out of it, but it is probably in decline after having been sticky. Not cheap to replace, therefore I'd clean it to verify the cause.

 

[Lit549]

So, you are saying cleaning the throttle body and the reset did fix the problem for a while? If I replied to your original post, which by the way you should have tagged this current info on to that thread, I would have also said to clean the Mass Air Flow Sensor with a cleaning kit from a parts store. Follow the directions. Did you do that too?


Everything else may be fine and you have an intermittent problem with the TPS.

Seriously I don't know how to "tag" the other thread, also yea I've done ALL of what was suggested and it did work for awhile but now it doesn't help at all..Intake gaskets/knock sensors/plugs and wires/ all done last year..

 

[Lit549]

how many miles?

197k on the engine,..

 

[Lit549]

wouldnt this be a classic symptom of a failing IAC valve? You could clean it and get more life out of it, but it is probably in decline after having been sticky. Not cheap to replace, therefore I'd clean it to verify the cause.

That's what I was thinking, I've removed it and cleaned it several times which worked for awhile but it always ends up doing it again..

 

[Doubeleive]

That's what I was thinking, I've removed it and cleaned it several times which worked for awhile but it always ends up doing it again..

the 2005 does not have a separate IAC it's all part of the throttle body, my first suspect with 197k miles would be the maf (mass air flow sensor), generally after 160k it's a gamble if they are going to make it much further, if you have a junk yard around you can pick up a used one pretty reasonable just to try it and see, it could very well be the throttle body or a combination of things. It's really hard to narrow it down without replacing parts especially with that many miles, if you have a tech2 or access to one you could run some test's, to me it's one of those things where you are caught between paying for a diagnostic+whatever parts are found to be bad -vs- just replacing parts and maybe saving some money and maybe end up having to have a diagnostic anyway.

 

[ak_yukon]

EGR valve