Is this because of torque management...?

GuyZ71 · July 17, 2005

Just got back from making a 32 hour round-trip to Florida and back. We took a '03 fullsize conversion van and it was equipped with the 5.3. It rolled down the highway just fine but I noticed that if you had to stomp it to merge into traffic or pass someone the van felt like it was completely flat. There was just no power to it at all! Is this what TM does to these vehicles? I was told my '00 Z71 doesn't have TM and I can tell you I certainly don't have this problem.

Another note while I'm talking about this van, I also noticed that if you were running the air and you got in it more than 1/2 throttle when accelerating or going up a bigger hill on the highway that A/C would stop. The air temp coming out of the vents warmed considerably and the fan nearly stopped. Is this a problem on the newer trucks? Again, my Z71 doesn't have this problem either.

MrQuadrasteer · July 18, 2005

Sounds reasonable.

GM GIMP · July 18, 2005

The 5.3 in a full-sized van on a hot summer day probably is just running out of power for passing. The weather has a big effect on power and the large van is pushing against a lot of air at highway speeds. I'm not trying to belittle your van at all. They're very nice vehicles.

On some vehicles, the computer will turn the AC compressor off at full throttle so it won't rob needed horsepower.

MrQuadrasteer · July 18, 2005

On some vehicles, the computer will turn the AC compressor off at full throttle so it won't rob needed horsepower.

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Yup, it's funny. I've seen little four-banger cars have a switch at the throttlebody, like a wot-nitrous switch... but it's to cut out the a/c !!!!

Hey.... get a no/nc switch, then you could cut out the a/c AND spray all at once for REAL passing poswer !!!!!

GuyZ71 · July 18, 2005

I take no offense, it's not my van. It's my friends van that I borrowed. It just seemed strange to me the lack of power this van had from a dead stop. My family's condo is right on A1A in Indialantic, FL and it's an extremely busy road. In order to pull out and get up to speed you almost have no choice but to floor it. When you floored this van it just felt like the computer or something was holding it back. I wondered if this was the TM system kicking in and if it was, I don't want a truck with that retched system.

dannyukonxl · July 19, 2005

I take no offense, it's not my van. It's my friends van that I borrowed. It just seemed strange to me the lack of power this van had from a dead stop. My family's condo is right on A1A in Indialantic, FL and it's an extremely busy road. In order to pull out and get up to speed you almost have no choice but to floor it. When you floored this van it just felt like the computer or something was holding it back. I wondered if this was the TM system kicking in and if it was, I don't want a truck with that retched system.

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yeah its pretty pathetic but i think the 5.3 in the vans are detuned a little, also you should take into consideration the gear ratios etc

Butch 02 Denali · July 19, 2005

I take no offense, it's not my van. It's my friends van that I borrowed. It just seemed strange to me the lack of power this van had from a dead stop. My family's condo is right on A1A in Indialantic, FL and it's an extremely busy road. In order to pull out and get up to speed you almost have no choice but to floor it. When you floored this van it just felt like the computer or something was holding it back. I wondered if this was the TM system kicking in and if it was, I don't want a truck with that retched system.

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yeah its pretty pathetic but i think the 5.3 in the vans are detuned a little, also you should take into consideration the gear ratios etc

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That is definatly the "abuse" mode kicking in. The abuse mode will retard the timing about 20 degrees when it thinks you're "abusing" the vehicle!! It will also override your gas pedal (with drive by wire) and close the throttle body if it feels that the 20 degrees of retard isn't enough!!! Don't confuse the abuse mode with the tranny torque management, two completly different things!

Sad that you almost HAVE to get a custom tune these days just to get the truck to run the way it should have from the factory!!! Most custom tuners will complety shut off the abuse tables, and reduce the tranny TM to half or less of what it was.