3 Attachment(s)
HELP! ETC limiting throttle opening with NO Codes (Log Inside)
I am helping a friend with a LS swap in his 1948 Chevy truck. He swapped in a complete take out 06 Chevy truck 4.8L with a 4L60E trans. He swapped all the components including the pedal, TAC module, wiring harness, UHJB and Electronic Throttle body. I have the MAF defaulted and I am tuning it in SD mode now because he installed a bigger camshaft, 226, headers and a 3000 RPM convertor. Everything else in the system is stock. The concern is after adjusting some of the low RPM and low throttle positions I had him roll into the throttle a little more to get into the higher TP areas but the engine has very little power. After looking at a lot of data I found out that the ECM will not allow the throttle to go over 40% with the engine running. I also noticed that the ETC pedal position goes to 140% when the pedal is on the floor. When the engine is off and the key is on the throttle assembly will work properly and go to 100% when the pedal in on the floor. Although the ETC pedal position still shows 140% when the pedal is on the floor even when the engine is off. Now when you start the engine the ECM will NEVER allow the desired and/or actual throttle position to go over 40%. Sometimes it is 36%, sometimes it is 38% and sometimes it is 40%. The engine runs fine with no misfires or codes set. Also the engine and throttle work properly as long as you do not try to open the throttle more that 40%. When you try to open the throttle more than 40% it will just stop at 40% and not go any further. The ETC never does go into full limp mode and default to idle either. No codes are ever set when doing this. I am guessing that the ECM is in throttle limiting mode but I can not find any codes or any data that would tell me why the ECM is doing this. Does anybody have ANY ideas and where to look for the cause of this concern? I have attached a log and the calibration for the vehicle. Please also note in the log that the wide band data is not correct because when I logged this drive my wideband wire fell out of the connector at my HPTuners Pro box. THANKS for ANYTHING you can suggest.
Dwight
Nashville IL
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