Turbo ls1 part throttle stutter.
Last edited by SSLogan; Dec 5, 2015 at 04:21 PM.
1. your bypass might be opening, when using a MAF sensor this leads to erratic operation. This theory is reinforced by the fact it runs fine at WOT (bypass is 100% shut) while at part throttle the bypass might be open.
2. How is the engine tuned
3. where is the maf sensor? and where is the turbo? I need to see all the plumbing to make an accurate diagnosis.
4. maf sensors require continuity. IF the turbocharger stalls (surges) at low-throttle, low rpm ranges it will whip the air at the maf hot-wire back and forth, you will see it on your data-logs as a maf voltage rapidly fluctuating. This is another common cause for issues when using a maf sensor with a turbo. The fix is to run a recirculated bypass valve that hangs open at idle and low-speed situations to prevent surge from influencing the maf hot-wire. If you are experiencing a slight surge as you tip into boost that is a different issue- the fix there is a smaller turbocharger or larger back housing. I doubt that is your problem (I had seen this only once on a 2.6L engine with the same size turbo)
The jerking around definetely sounds like a fuel related issue and because you have a maf and atmospheric bypass I am strongly suggesting it is your plumbing/design/maf related.

