Weird Start

MD Chevy · July 29, 2012

So I actually got to use my truck as a truck the other day. I was pulling out some stumps from some weeds. Nothing major but I did have to use 4Lo. I did notice something that is new to me, when I was in 4Hi I would give it gas and it would only rev to about 1800-2000 RPMs and that was it. I had it to the floor and it wasn't moving anymore. Has anyone else experienced this? I do have a 4.8 with 3.42's but when I am on grass I would think it would slip and let me spin some, but absolutely nothing.

03blackz71 · July 29, 2012

sounds like it is stuck in 4LO.

BlackZ71Silverado · July 29, 2012

Were your tires spinning while in 4Hi? If so, that damn traction control and stabilitrac will cut power. Not sure how high it will allow the engine to rev because I always turn mine off when doing work like that. Try it on solid dirt without the tires spinning and see what happens.

MD Chevy · July 30, 2012

I thought it might be the traction control and stabilitrak. Just to mess around I went out on pavement turned both off and tried to get my tire to spin. I know the 4.8 is weak, but my 04 5.3 would burn both tires no problem, but it would not rev over 1800-2000. I figured it was some type of safety thing, but I really think something might be wrong.

Wires · July 30, 2012

My guess is the tires hooked up, and since you are starting from a dead stop, The PCM is detecting that the throttle is being pressed with no increase in RPM's/wheel speed. It's probably limiting the actual throttle to prevent you from frying the torque convertor and tranny.

When you try this on ashpalt, the truck is moving so it won't retard the power the same.

desrtrat · July 30, 2012

sounds like you hit your stall speed in your TQ converter. if your tires were not moving, than that's it.

MD Chevy · July 31, 2012

Is there anyway to change that setting? I don't like to do burn outs, but on grass you would think I would spin or the RPM's would go higher.

Wires · August 1, 2012

There is no setting. It's governed by the physics of the design. Hold the brake, and step on the gas, and the engine will only rev so high. That's life with an automatic. Always has been, always will be...