Changed out my intake and TB a couple months ago. After doing so, the car would bog down at high rpm. Initially I thought it was a shifting problem, but during a dyno tune, the fuel would cut off at high RPM under a load. When the load was removed, the fuel stayed strong. This problem initially arose after changing my intake from LS1 to LS6 and a new 85mm TB. I have tried changing out the TPS and running with the MAF unplugged, but the issue still stands. Any ideas?


Original post: https://ls1tech.com/forums/generatio...take-swap.html

 

You didn’t tell us much about the engine mods or the fuel pump but it sounds like the fuel pump can’t keep up with the load. If you are still running the original fuel pump it most likely is getting tired by now. Have you checked the fuel pressure during a run?

 

just a couple thoughts A. do you have stock ls1 springs? they will bounce / flutter (mine did at 5700). B. are you hitting the rev limiter? C. are you hitting the 162 mph fuel shut off on the dyno? D. are you throwing any codes? when i swapped intakes i broke a teeny tiny wire going to the back of the intake which through a low manifold vaccum pressure (i think) and my car ran in limp mode , very little power. goodluck!

 

All my mods are in the sig. Fuel pump and injectors are still stock. Springs are PRC dual .650s. Rev limiter is not being hit before the fuel cutoff. The cutoff is not from the 162 mph either. This cutoff happens randomly and kicks the SES light on. If I have a passenger in the car, 9 of 10 times this will occur. The code usually reads TPS low voltage.

 

Have you tried loading a speed density tune in it? My MAF always cut my fuel around 5000 RPM until I went with speed density tune.

 

Haven't tried a SD tune yet, but its definitely in the near future.
I tried another TPS just to rule that option out. So far so good.