'03 Tahoe Idle Issue

[BMFScout]

My friend has an '03 Tahoe, not sure if it's 5.3 or 4.8, but V8 and 2WD nonetheless. When it gets cold it throws a check engine light (haven't pulled the codes yet) and decides to idle low/erratic, especially when really cold.

I will pull the codes soon, but Fred said it might have something to do with the drive by wire kanuter? (not his exact words) and that J.C. and Buttkiss had similar problems? Anyone have anything similar happen? TIA.

[robertf03]

two of the people I used to work with had 5.3 trucks with the electronic throttle and both had flashing lights in cold weather. Theres got to be a TSB for it if its this common

[StevenAg03]

Idle Air Controller maybe?

[robertf03]

they don't have one, the throttle/iac/cruise control and I think some gay rev limiter/traction control stuff is all in one motor

[StevenAg03]

guess its that motor then... :flipoff2:


tell me another engine issue and ill solve that one too... :gigem:

[robertf03]

did the suburban do this crap when the crank sensor went out?

[Seth]

how many miles?

[BMFScout]

60-ish thousand

[bburris]

My truck had a 6.0, but it stopped after I cleaned the K&N really well.

[BMFScout]

did the suburban do this crap when the crank sensor went out?

I don't think it idled weird, it was more of an all or nothing deal. Would just cut out.

[bburris]

My truck also just did the weird idle thing while holding the brakes with the trans in gear. If I put it in Park at a stop light it wouldn't do it.

[BMFScout]

John Cox didn't you have this problem with your pickup?

[agjohn02]

kinda. i had low idle, no SES light, and not particular to cold weather. i fixed it by taking the throttle body apart, looking at it, almost getting killed in a BMW, then putting it back together. it works great now.

[Graystroke]

I would try cleaning the the throttle body flap and the IAC motor thing. Flem you said it was all one motor...does it still have a plunger like a taditional IAC? If so maybe it is dragging or the seat is gunked up? Don't have any experience on LS motors. On anything else, where I had a similar issue, it was the EGR or the IAC. the EGR can certainly cause weird idle problems and a surge if it is acting up... Leah's
bastard Honda Passport (w/ the Isuzu motor and GM engine management :rolleyes: ) started surging, pinged on the highway, would idle high sometimes and then barely idled and threw a check engine light, after a week. I pulled the codes and it was a "dealer only code" :rolleyes: according to Vatozone. I googled the code and it was an EGR code. New EGR was $185 IIRC. I pulled it and sprayed it down w/ some cancer causing Berryman carb cleaner and all has been good for over a year.
My RR always runs better after the IAC, throttle body, and PCV is cleaned out...worth a try and cheap anyways.

[agjohn02]

I would try cleaning the the throttle body flap and the IAC motor thing. Flem you said it was all one motor...does it still have a plunger like a taditional IAC? If so maybe it is dragging or the seat is gunked up? Don't have any experience on LS motors. On anything else, where I had a similar issue, it was the EGR or the IAC. the EGR can certainly cause weird idle problems and a surge if it is acting up... Leah's
bastard Honda Passport (w/ the Isuzu motor and GM engine management :rolleyes: ) started surging, pinged on the highway, would idle high sometimes and then barely idled and threw a check engine light, after a week. I pulled the codes and it was a "dealer only code" :rolleyes: according to Vatozone. I googled the code and it was an EGR code. New EGR was $185 IIRC. I pulled it and sprayed it down w/ some cancer causing Berryman carb cleaner and all has been good for over a year.
My RR always runs better after the IAC, throttle body, and PCV is cleaned out...worth a try and cheap anyways.


YAWN!!!

[BMFScout]

I'm thinking intake gaskets since it only does it when cold, we'll see what we can come up with tonight.

[Graystroke]

YAWN!!!
I know! It's almost as bad as this....ALMOST!

http://tamor.org/forums/showthread.php?t=9466

[BMFScout]

http://tamor.org/forums/showthread.php?t=5942

[Graystroke]

http://tamor.org/forums/showthread.php?t=5942
huh?

[BMFScout]

I thought we were posting up boring threads?

[agjohn02]

I know! It's almost as bad as this....ALMOST!

http://tamor.org/forums/showthread.php?t=9466



dont make me count how many questions you asked in that thread

[Graystroke]

dont make me count how many questions you asked in that thread
the start of the thread is really boring....I was just trying to be nice. 100cc mopeds (YAWN!!!!) or thumping nitro injected v-8's hmmmm.

[agjohn02]

well, lets see your thumping nitro v8, big nuts

[BMFScout]

checked out lots of stuff, nothing worked. any ideas?

[Graystroke]

what did you try?

[BMFScout]

cleaned throttle body blade, checked anything to do with vacuum, swapped MAF with one we had sitting around, checked torque on intake gaskets, checked fuel pressure, pulled one plug looked lean like the codes said. The truck only gets short trips put on it, 2-3 miles at a time so clogged stuff makes sense. Maybe clogged injectors? Fuel filter was replaced earlier this year.

[Graystroke]

fuel pressure regulator? maybe check fuel pressure

[BMFScout]

checked fuel pressure

good idea! :flipoff2:

Fred thought it might be the regulator, but the pressure was the same as his so we kind of ruled that out.

[Fredo]

I told Jimmy we should try swapping the transmissions between this one and mine and see if that fixed both of them. He didn't go for that idea.