[abl1597]

Hey Guys, It's been a while since I've actually made a post of my own having a problem. But, for the last 3-4 months I'd say my truck has had a problem with low end power on take off. It's a 2006 Chevrolet Silverado 1500 4x4 ext cab z71 5.3L v8. The only past problems I've had is back in 07 I had to replace the knock sensors at a year old, and last year ('10) around december I had to replace the mass air flow sensor. At the same time I did that I went ahead and replaced the spark plugs and wires and ran seafoam through the brake booster line (no white smoke came out). The truck has 82,000 miles now. Anyway, it only bogs down on take off, when you already have speed and stand on the gas it will shift down and take off, but from a stop it will not spin a tire or if your on a hill it doesnt even have the power to get up it. This is very aggravating when you're offroad and you cant get out of a hole because it feels like the truck just doesnt have any power to turn a wheel, it just bogs down. I've taken it to 2 different mechanics and they can't find anything wrong. It isn't throwing a check engine light or any codes. Both mechanics say fuel pressure, fuel pump, and fuel filter are ok, computer says everything is ok, and air filter/intake is all clean. I know there is definetly something wrong with the truck because used to when I hit the gas coming out of a red light I could squall those tires and now it hardly moves. I'm getting really frustrated because everyone is telling me it checks out ok. I need help or any kind of advice would be much appreciated!

Thanks Guys!:neutral:

 

[silveradotrailblazer]

If you put anything but A/C Delco spark plugs in your truck, I'd start there. These trucks just run better with A/C's. Also remove the throttlebody and clean both sides with a throttlebody cleaner and a soft toothbrush.

 

[BillM]

This may sound crazy, but the ECU may need to be checked. If you know some one that has HPTuners on a laptop, invite them over and have them plug into your computer. It will show all your lean or rich areas for specific RPM ranges. There are tables set up on the ECU that tell the engine if it needs more fuel or less fuel. You may just need to reload your stock program to get back to normal. HPTuner software will also allow you to make modifications to the tables. This is important especially if you have made changes - CAT back exhaust, Cold Air Intake, etc.

 

[sstoner911]

Have you checked your catalytic converters? They may be "clogged".

 

[abl1597]

Well guys I don't know what to do now. I let one of the best mechanics in town have it for a couple days and he ran a series of tests on every area of the truck, everything checks fine. Fuel pump, fuel filter, fuel pressure, knock sensors, MAF sensor, air filter, hoses, spark plugs(ac delcos), wires, transmission, and catalytic converters all check fine. The mechanic said he had a buddy with a car lot bring in a truck just like mine and it drove just like it. He says everything is fine. I know I'm not crazy and everything may check out fine but I know it has a problem. Ive had the truck for 4 years now and it used to take off as soon as I hit the gas. Hell if I'm having trouble taking off now I'll never be able to pull my trailer, so the truck is useless.:grrrrrr:

 

[Sierraowner5.3]

i may be way off here, but it kinda sounds like my truck a bit when i first stand on it from a stop its kinda slow to go, but from a roll at even 10 its got good power, it may be something in the fuel trims in the computer.

i know my truck takes off kinda slow when i romp on it from a stop. im pushing 340 horses I cant even get it to chirp the tires from a stop. its got something to do with the fuel trims/torque limiting system I think.

just my .01 worth tho.

Alex

 

[BillM]

Fuel Trim tables in the ECU! That is the word that I was looking for in my last post. But, if your mechanic said that every thing is OK with the programming, then there is no problem???? The obvious things have been checked out, and that leaves only the ECU left. The service reps of a performance Chevy dealer, especially Corvette dealers, know someone with HP Tuner software. And, they can check out your program. Dealers cannot do those proformance checks/upgrades due to liability and warranty concerns.

 

[SoundZman]

I have a very similar issue. Mine as well started with a Knock Sensor failure that I let go for months. What I've discovered during the research of the knock issue was when the sensor goes into a failure condition the ECU put the A/F map into a rich condition to protect the motor. However this causes excessive fuel in that bank which causes the Cat to run extremely hot. Well in my case, after months of neglect, I now get Cat Efficiency codes...this week I'm getting a the cat replaced.

This may not be your case but it sure sounds a lot like the way my issues started.

 

[Josh White Silverado]

I am having the exact same problem with my 2005 Silverado. Did you ever figure out what the problem was?

 

[Josh White Silverado]

Hey Guys, It's been a while since I've actually made a post of my own having a problem. But, for the last 3-4 months I'd say my truck has had a problem with low end power on take off. It's a 2006 Chevrolet Silverado 1500 4x4 ext cab z71 5.3L v8. The only past problems I've had is back in 07 I had to replace the knock sensors at a year old, and last year ('10) around december I had to replace the mass air flow sensor. At the same time I did that I went ahead and replaced the spark plugs and wires and ran seafoam through the brake booster line (no white smoke came out). The truck has 82,000 miles now. Anyway, it only bogs down on take off, when you already have speed and stand on the gas it will shift down and take off, but from a stop it will not spin a tire or if your on a hill it doesnt even have the power to get up it. This is very aggravating when you're offroad and you cant get out of a hole because it feels like the truck just doesnt have any power to turn a wheel, it just bogs down. I've taken it to 2 different mechanics and they can't find anything wrong. It isn't throwing a check engine light or any codes. Both mechanics say fuel pressure, fuel pump, and fuel filter are ok, computer says everything is ok, and air filter/intake is all clean. I know there is definetly something wrong with the truck because used to when I hit the gas coming out of a red light I could squall those tires and now it hardly moves. I'm getting really frustrated because everyone is telling me it checks out ok. I need help or any kind of advice would be much appreciated!

Thanks Guys!:neutral:

Did you ever get it fixed? I am now having the same problem on my 2005 Silverado 5.3 4x4 crew cab!

 

[xPosTech]

You're asking a new member from 2011. Still a new member means he has only a very few posts. I doubt he is still active.

You might get a better response by starting a new thread listing your symptoms and pertinent truck info.

Ted

 

[Kevboys69]

Change the TPS.

 

[Zach Smith]

Out of curiosity, how many of you/ having this problem still have the o.e. battery in it? Just the start of a theory, I have never seen this problem before.