mbennett

Please help - any advise is appreciated.

2001 Tahoe 2wd, 5.3, Auto, 55k, purchased used in 07-03.

No indication of any issues (No check engine light)

Idle speed according to Tach is 450 - 500 in Park.
When you move into gear, D or R, bounces down to 300-350. Lights also go dim. Seems to want to stall.

This has been an issue since we bought it in July 03. I have had it stall on me once when going from Reverse to Drive and hitting the gas.

It has stalled on my wife twice this week when she was in heavy traffic just coasting. Battery light comes on and it stalls. Starts back up fine and away we go.

When it stalled the first time this week, I took it to Autozone to get the battery checked. Checked good the first time, started the truck to check the alternator (checked good) and when he checked the battery a second time it showed bad. Got a new battery. In the process of changing the battery, the + post broke clean out of the old unit. It was rusted and leaking for some time. I was sure I had found the issue and now the RPMS were steady at 500.

Tahoe stalled again today in traffic. I called dealer service to get some advise. Tech said Park RPMs should be around 750. Gear RPMs should never be less than 500. This thing has never seen 750 setting still. He agreed with me that it sounds like the TPS (Throttle position sensor) He said if it is bad causing things to be low RPMs it will not peg the Check Engine.

Our 01 Tahoe is also drive by wire (electronic Throttle control) instead of cables. He said that the TPS is not something I can replace myself because it has to be calibrated with the computer at the shop.

Anyone had this happen?
Does this sound like the issue?
What else can I check?
Is the tech right, or can I change this myself and see if that is the issue?
Can anyone verify the RPM ranges for idle vs Drive on a 5.3 tahoe?

bdubb

iTrader: (2)

VERY easy fix. I almost got into some wrecks because of my truck stalling on me. What you need to do is clean the throttle body. Disconnect your heater hoses, unclip the plugs, and take off the throttle body by the three(?) nuts. Take some form of carb cleaner, I used One Shot, and clean behind the thottle blade and the entire bore of the TB. Then gently clean the reusable gasket (without removing it from the intake) and then try to clean area at the front of the intake port just in the inside. Just be sure not to get any debri from the rag or anything left in the intake. Bolt it all back up and start the truck. It may not want to run the first start or two, but let it clear the cleaning agent you used out and then it should run just fine.

I had this problem for a long time and then learned about the TB blade sticking from the gunk buildup. I have not had a problem since cleaning behind the blade. Be sure to use a spray clear and not to submerge the TB in anything due to the electronics.

Hope this saves you some money and some hassle of finding the problem. If the problem continues, then I'd take it to a dealer or shop.


I don't mean for this to be degrating to anyones mechanical skills. Just easy to understand for everyone.