Throttle Body

BigSilver · December 5, 2008

Suburban 2003, 2500, 6L, 200,000+km

With Engine OFF, ignition turned ON:

I hooked up a throttle body (TB) to the engine's wiring to see it operate/ respond to accelerator pedal (AP) input.

What I noticed is that the TB's baffle would flutter as it repositioned to AP input.

I have since replaced the AP sensor and TB too. The TB does not have a separate external TPS. The flutter still occurs.

This flutter effect, with a running engine, translates to uneven acceleration.

So I was just wondering what might be causing the jitter/ flutter effect?

alwcurlz · December 5, 2008

Suburban 2003, 2500, 6L, 200,000+km

With Engine OFF, ignition turned ON:

I hooked up a throttle body (TB) to the engine's wiring to see it operate/ respond to accelerator pedal (AP) input.

What I noticed is that the TB's baffle would flutter as it repositioned to AP input.

I have since replaced the AP sensor and TB too. The TB does not have a separate external TPS. The flutter still occurs.

This flutter effect, with a running engine, translates to uneven acceleration.

So I was just wondering what might be causing the jitter/ flutter effect?

Sounds like it needs to be hooked up to a scanner to get some codes. Could also be the Mass Air Flow sensor. Are you running this with the air tube removed? It won't run right with that off either since the MAF is not getting any airflow feedback.

BigSilver · December 5, 2008

Suburban 2003, 2500, 6L, 200,000+km

With Engine OFF, ignition turned ON:

I hooked up a throttle body (TB) to the engine's wiring to see it operate/ respond to accelerator pedal (AP) input.

What I noticed is that the TB's baffle would flutter as it repositioned to AP input.

I have since replaced the AP sensor and TB too. The TB does not have a separate external TPS. The flutter still occurs.

This flutter effect, with a running engine, translates to uneven acceleration.

So I was just wondering what might be causing the jitter/ flutter effect?

Sounds like it needs to be hooked up to a scanner to get some codes. Could also be the Mass Air Flow sensor. Are you running this with the air tube removed? It won't run right with that off either since the MAF is not getting any airflow feedback.

Never ran it without the air tube. The flutter was only visible with another TB temporarily plugged into the wire loom, while the electrical was just energized and engine not running. This was a static test for visual benefit.

The pulled code was p1125. So the TPS, that's connected at the accelerator pedal was replaced and the flutter remained.

alwcurlz · December 5, 2008

Suburban 2003, 2500, 6L, 200,000+km

With Engine OFF, ignition turned ON:

I hooked up a throttle body (TB) to the engine's wiring to see it operate/ respond to accelerator pedal (AP) input.

What I noticed is that the TB's baffle would flutter as it repositioned to AP input.

I have since replaced the AP sensor and TB too. The TB does not have a separate external TPS. The flutter still occurs.

This flutter effect, with a running engine, translates to uneven acceleration.

So I was just wondering what might be causing the jitter/ flutter effect?

Sounds like it needs to be hooked up to a scanner to get some codes. Could also be the Mass Air Flow sensor. Are you running this with the air tube removed? It won't run right with that off either since the MAF is not getting any airflow feedback.

Never ran it without the air tube. The flutter was only visible with another TB temporarily plugged into the wire loom, while the electrical was just energized and engine not running. This was a static test for visual benefit.

The pulled code was p1125. So the TPS, that's connected at the accelerator pedal was replaced and the flutter remained.

Did you clear the computer and see what codes come up? May need to check wiring to the APP system.