I recently finished building a iron ls1 for my truck. It has 42# Delphi Injectors, Comp Cam 219/227, 11:1 Compression, DCR is around 8.75:1. After start up it ran okay and once I began tuning it ran great till about 4000rpm. Which is as far as I got in rpms before it started acting up. Now after about 200 miles it is either really rich or really lean from idle till 4000rpm. No matter where I set the VE add or subtract it goes the other direction (Rich or Lean). Both my wideband and my O2's agree on this (7.4 or 20.1). When I turn on fuel trims it switches really fast between the two. It just can't find a middle ground to run. I am stumped because it ran great for 200mi then this. Please, help it is my DD. Have had to drive my mud truck lately and no a/c is not my favorite in Texas heat. Thank You, in advance
Since I can't post a tune here I will link the thread I started on HP Tuners Forum.
HPT Thread
Let me make a list of what I have checked and tried.
1. All grounds are good: PCM, Battery to engine and body, both on back of the motor, and the one by the power steering pump.
2. Fuel pressure is 53psi with vacuum and 60psi without.
3. Have tried every combination of injector data from HPT Repository that has 42lb to 60lb injectors. Seriously I have flashed my truck over 100 times. Ran fine on previous data till I parked it for several hours.
4. New O2's went in with the motor 200mi and 2 weeks ago.
5. All injectors and coils are firing checked by way of cylinder drop test.
6. All input sensors are giving the HPT Scanner good readings.
7. Not a vacuum leak, smoked the intake system.
8. Not the injectors installed new ones from FIC with correct data.
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