4.2 Intake Manifold need help

[Zboymadeinusa]

Hello all,
I’m pretty new to the forum and this is my first post. I have a 2004 3.9 V6 and I swapped the upper intake manifold from a 4.2 onto it. I pretty clearly made a mistake, as my car now thinks it is at 18% throttle position (checked with live feed obd2 reader) when I’m completely off the gas including at a standstill. As soon as I press the in clutch while moving the rpm starts climbing until it hits about 3000. The throttle body is completely closed when this happens so my guess is when I extended the TPS connector I used the wrong gauge wire causing less resistance and a misread of throttle position? What gauge wire should it be? Any other suggestions are greatly appreciated too!

 

[wmburns]

I extended the TPS connector I used the wrong gauge wire causing less resistance and a misread of throttle position?

^^this is NOT your problem. Using a larger size wire for a low voltage sensor isn't going to CAUSE the sensor to read incorrectly. IMO your problem is else where.

NOTE; it is normal for the engine load PID to be around 20% when the motor is idling.

Suggestion. Trouble shoot this issue by looking at::

• The TPS voltage
• The TP-mode (closed throttle, part throttle, WOT).

Review the information here. Pay attention to the part about HOW the PCM to determine the TP-mode.

Troubleshoot IAC idle problems 1996-2004​

Troubleshoot IAC idle problems 1996-2004

Back to the basics. Check for blown fuses. Especially fuse F2.2 and F2.8 in the Central Junction Box (CJB 1999-2004 MY). Confirm key on power using a known good ground. 1999-2004 MY fuse panel schedule...

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