11 bogging down hesitation stutter

jomac0321 · September 24, 2022

I just bought a 2011 Silverado 1500 LT 5.3L z71 it has the 3.42 gears. When ever I try to take off from a low speed/rpm’s the engine hesitates and just feels like it’s being held back til it hits over 2500rpms if I try to turn slow and go up a hill it will bog all the way up the hill unless I put it in Manuel mode and drop a gear to raise my rpms, it almost feels like it’s just in to high of a gear but there is still a hesitation when taking off its like the rpm’s get stuck for a second at a certain spot then it catches another thing idk if it’s related is when I put it in gear and let off the brake it will slowly accelerate on its own. When I bought it it showed code for map sensor replaced that no change, I updated driver side valve cover for new pcv design cause after first time I drove it home when I cranked back next morning it blew smoke and could smell oil, new cover fixed that though. Everything on live data looks good and no codes except when it hesitates/bogs the spark advance is I’ll drop to between -1 and -6.5. Thought maybe cats stopped up so I removed them with no change. Anyone that can help give insight please let me know

Barry Hanback · September 30, 2022

I have a 2013 Sierra with the 5.3 and it sometimes does that and will die if I try to accelerate. I turn it off and it starts back and runs fine. I put a new fuel cap on it, and thought that fixed it, but it didn't, I'm now suspecting that the purge valve is sometimes leaking. I had one go bad on my 2015 Cadillac SRX and it acted similar to that, and a new purge valve fixed it. I'm going to test my valve before replacing it. You can search how to test the purge valve and get great instructions. It's simple and easy to test. I do not get the purge valve code on my truck, but sometimes it says to tighten the fuel cap. I don't know if they throw a code till they're really bad. Just my thoughts, I don't like to throw money at a problem just to see if it does it. I try to troubleshoot first.

Edited September 30, 2022 by Barry Hanback
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