Big Bu Bu

iTrader: (4)

After several tuning attempts by some well known tuners, my head and cam LS6 FAST LSXr102 with 90mm TB continues to have intermittent issues. The car will run fine and then all of a sudden it will surge at idle, stall (fall straight down) when pushing in the clutch at cruising speed. It sometimes surges big time on start up. Since these issues are not always repeatable all the time we're beginning to feel we have a bad TB. The car has been tuned by Vector, Modern Muscle and Speed Lab. At first it was just driveability issues at low speed. Meyers at Modern Muscle did a great job solving those low speed issues, but then we had so much non repeatable stalling and surging at regular speeds, he's thinking we have a problem that's not software related. I thought if the TPS sensor was bad it would throw a code. We get no codes. Any second guesses out there when tuning is not working? I'm ready to go to a Nick Williams 102.

GEAUX FAST

I am having some similar issues with mine, reving, surging, poor part throttle pretty much everything you mentioned, I unplugged my TPS and it seemed to make a diffrence, I too have no codes ...

scites

iTrader: (30)

first step in trouble shooting..change the cheap easy part first..id try a tps sensor and clean your TB before dropping the money on a new TB

5.7 ute

These days, the first rule is to scan the vehicle while the problem is occuring & use this info to diagnose the faulty part. If you have no access to a scanner, I would try borrow a known good part before ponying up for a new one.