Help with a H/C Trex!
10-09-2009, 08:24 AM
#1
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Help with a H/C Trex! Hey guys Im pretty new to HP tuners and ive held off posting until Ive tried just about everything I could find through searches... The engine is a forged LS1 stock cubes, Trex, PRC 2.5's, LS6 intake ported TB and 37lb injectors. It wont idle to save its like and feels like its only running on 7cyl below ~3k rpms. I have a tune thats from another car thats nearly identical that I used as a known good starting point and nothing I change seems to help... Im not gettign any codes. heres a scan and two of the tunes I tried. THANKS!
10-09-2009, 09:22 AM
#5
Bank 2 is WACKY. It's LTFT is adding 25% (maxed out) while B1 is at -6/-8. The STFT is nutso too, adding over 75% to that side. You have a misfire there most likely. Look at your narrowband voltage; B2 is flat and unresponsive through the log.
I bet it runs like butt. B2 definitely needs some physical attention. Check plugs and wires firstly... In the mean time, if you must drive it, reset the fuel trims through scanner and disable closed loop. At least in open loop it won't flood the crap out of B2 like it is now.
I bet it runs like butt. B2 definitely needs some physical attention. Check plugs and wires firstly... In the mean time, if you must drive it, reset the fuel trims through scanner and disable closed loop. At least in open loop it won't flood the crap out of B2 like it is now.
10-09-2009, 10:22 AM
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Ya the O2 is the first thing im swapping out tonight and NO the car is sitting in teh shop till I figure it out. BUT the O2's shouldnt affect the start up idle right?
10-09-2009, 12:25 PM
#7
No, you are right. Sounds like a solid misfire issue. You can swap the O2s left to right and see if the problem follows, but it likely won't (since this appears REAL). A cam that size can make a misfiring cylinder hard to hear. I bet is absolutely REEKS of fuel at idle though.
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10-09-2009, 01:42 PM
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Ive got a couple known good O2's so I plan to just swap them out. The car has been run up the road a few times on the bad O2. Im hoping that the O2 being bad fouled out the plugs and are causing the mis fire... The problem with the miss fire theory is that i fired it up and let it run for about 15 seconds to try to find the dead cyl and they were all hot..... its frustrating to say the least..
10-09-2009, 11:38 PM
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OK so replaced the O2 and the plugs, the bank 2 plugs where fouled pretty bad. I fired it back up and reset the fuel trims and it still wouldnt idle. I made the changes in the attached file and got it to idle but if you look at the log it has a nasty stumble right at tip in... also it wont come back down to idle after you rev it up, itll come down to about 1500-1800 rpms and 35 degrees of timing, as soon as you drop it into gear it drops the idle and then shift back into neutral and itll hold the idle... but always has a stumble on tip in... Any ideas?
