LQ9 Throttle Blade not opening fully DBW 2004 Escalade enging swap into 96 Impala

[VF1000R]

Started off good. Tuner had engine running good, dynoed almost 400 RW. Drove car for a while and found that engine had a tendency to die at stop light or slow turn.

Tuner rechecked and made some adjustments but was not able to "fix" the issue. Then found out if the AC was turned off , engine ran good. So, added window switch to compressor circuit to kick in above 1300 rpm. That worked fine.

However, the real issue was found out before adding the switch. Somewhere during all the "adjusting" the throttle blade started not opening fully. Car ran fine , but only had medium power.

I swapped TB, TAC Module, Pedal Position Sensor and no dice.With scanner plugged in , engine on or off, TPS shows 55% at full pedal. Visual inspection confirms this. 18% at idle.

Background: Engine is a LQ9 out of a 2004 Escalade, complete pull out,

I freshened up the bottom end, had a 706 head off a 5.3 cleaned up and installed . Comp about 11:1, Installed BT Stage 3, with 52 injectors. 2007 TB Manifold. Headers, thats it.

Im not a tuner but will relay any inputs to my tuner. Car is a 96 Impala/4L60e with custom wiring harness from South Florida. $1000 worth.

Also , noticed that cruise control has stopped working. Not sure if that means anything.

Really would appreciate any input or questions. Im Stumped.

[Jon S.]

You mentioned using a "2007 TB Manifold" - assuming that this is a Gen 4 intake manifold setup for a 4-bolt 90mm throttle body.

What throttle body are you using ?

Regarding Gen 3 DBW Cruise Control - it will be inhibited if you have active DTCs (MIL on), or if your tuner has disabled DBW related DTCs.

[VF1000R]

You mentioned using a "2007 TB Manifold" - assuming that this is a Gen 4 intake manifold setup for a 4-bolt 90mm throttle body.

What throttle body are you using ?

Regarding Gen 3 DBW Cruise Control - it will be inhibited if you have active DTCs (MIL on), or if your tuner has disabled DBW related DTCs.

Using an Adapter for 3 bolt TB.

[VF1000R]

Any Help ?

[VF1000R]

The local tuner shop Im using is convinced that the problem is with either the wire harness or the ecm. Something about a possible fuze? Im not so sure. real frustrating as the shop is booked up and I have to leave the car there for weeks just to get them to take time and try to figure this out, so any help would be appreciated. Im fully capable of checking circuits and wiring but ecm is outa my wheelhouse.

[5FDP]

The throttle body, APP and TAC are from the same vehicle too right?

[VF1000R]

The throttle body, APP and TAC are from the same vehicle too right?

yes

[VF1000R]

yes

Another symptom has shown up. The speedometer is 10 mph fast.