I have a 2003 6.0, l92 head, comp cam, procharged silverado with a 4l80e with a 3600 vig stall. I got it fully dyno tuned but my only problem is the torque converter locks and unlocks at low speeds. I also got a po300 misfire code once but it has not came back. not sure but it i think it started happening after i installed my l92 heads with l92 manifold and went up to a 90mm throttle body from a stock 78mm and a dr x link to run the 90. any advice would be great thanks
This is just a shot in the dark, but try disabling your p0121 test under the general section of engine diagnostics by setting max to 100, and min to 0. I had this problem with my 408 with the 90 mm throttle body. The ECM doesn't see enough throttle movement with the 90 At crusing speeds because it is not needed so it locks the converter so that you have to lean on the gas to accelerate and this is when it checks the throttle position sensor.
Also most 4L80 files unlock the TCC at under 5% NO MATTER WHAT.
i tried disabling the po121 test and made no difference but the po300 random misfire keeps comming back. could this cause the converter to do this? i need to check to see what is causing the misfire. thanks for the help
Yes misfires will make the converter unlock.
Max out your missfire tables.
I believe he is saying anythng under 4% TPS it TCC unlocks!!
Yes they do that in the 80E,so do the 08-10 trucks
X2....most stock vehicles don't notice it due to the tight stall.Originally Posted by vortec
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