Low idle 2003 TB

[JimShoe]

TB idle is at 500rpm. At times this will cause it to stall. Is there a way to adjust the idle or does this point to some other problem?

 

[The_Roadie]

How accurately are you measuring the idle? The tach needle has errors. If you're looking at the data stream with a scan tool, you can see what it is exactly. When warmed up, it should be 620.

The idle is set electronically by the PCM and can't be adjusted without tuning software. No idle screws or any of that old school carburetor stuff.

That said, the engine should not just stop. If it's an issue that goes away if the AC if turned off, that's a well-known dirty throttle body. How many miles, and have you ever cleaned it?

http://gmtnation.com/f25/how-clean-4-2-inline-6-throttle-body-221/

 

[JimShoe]

TB has 80.000 and the throttle body has never been cleaned. I'll be doing that soon. I read the article and will be using that to help. Thanks. I was just reading the TB tach.

 

[The_Roadie]

The definitive test is if the idle stays more constant if the AC is turned off. Or if the engine used to idle OK but started acting up after a battery disconnection or total discharge for any reason.

 

[JimShoe]

The TB used to idle more evenly, but I had to disconnect the battery to replace the power steering lines. After that it began acting up. Does that point to throttle body needing cleaned? From everything read it should have already been done. Am cleaning it tomorrow. Thanks.

 

[The_Roadie]

...Does that point to throttle body needing cleaned? ...

Precisely. Many of us do it every 30K. Take pictures of the far side - it will probably look like the inside of a spittoon from a bar in Dodge City from 1880.

 

[Hypnotoad]

I don't mean to hijack, but is there an idle relearn procedure?

I cleaned my throttle body and it helped a little with the idle. Before the cleaning it would shut off every once in a great while. After, it low idles like it might shut off, but it hasn't yet.

 

[McGMT]

I don't mean to hijack, but is there an idle relearn procedure?

I cleaned my throttle body and it helped a little with the idle. Before the cleaning it would shut off every once in a great while. After, it low idles like it might shut off, but it hasn't yet.

nope... 625 or so is what ya` get...

 

[ksimm92]

+1 for the throttle body, i had a similar issue with mine.

 

[The_Roadie]

I don't mean to hijack, but is there an idle relearn procedure?

Disconnecting the battery during the cleaning forces the relearn process.

 

[JimShoe]

Throttle body was dirty. Cleaned up and the idle is staying between 600 and 700 rpm. Finally a job that was reasonable Thanks for all the help. Now onto the front brake caliper not releasing.