[sdtsdt]

The previous owner of my 2005 GT had installed a BBK TB unit. After experiencing several trips to failsafe mode ( code P2106 and P2135 ) I have decided to re-install the original OEM TB .. Luckily, the previos owner still had it. However, I see that the BBK unit used longer screws. What size are the original mounting screws and do the originals also install with an allen wrench? Also, I am assuming that the TPS voltage had to be set on the BBK unit upon installation, so I am hoping the the original unit's setting should already be good. The original owner says that he did not "tinker" with the original unit. Is that a safe assumption? If not, I guess I'll know when I start it up. Is there anything else that I should be looking out for? Thank you. I am new to Mustangs and trying not to shoot myself in the foot. Thanks again ... Steven

Ooops ... almost forgot... Can I get screws for TB at a hardware store, or, do I need to go to dealership?

 

[travelers]

The originals are studs. you could cut the bolts you have down or measure for new bolts. You will need to have the tune adjusted back to using the stock T/B.

 

[stlwagon]

The BBK required transfer of the TPS and throttle actuator motor from the OEM piece. You'll need to put those back on. Here's a good writeup about a swap to a GT500 TB. The process of checking the TPS voltage is the same.

CHECKING TPS VOLTAGE
To check the TPS voltage you must have a DIGITAL voltmeter.
1. Reinstall the stock throttle body.
2. LEAVE THE THROTTLE BODY MOTOR UNPLUGGED (the small connector on the driver side of the throttle body).
3. Ground the black wire of your meter and poke the probe of the red wire on the meter into the YELLOW wire of the TPS sensor which is the bottom wire on the plug located on the passenger side of the throttle body. You DO NOT need to break the wire to read voltage. The best way to probe the yellow wire is to poke the probe into the plastic harness plug (while it’s plugged in to the TPS). You will need to penetrate the blue insulator the goes around the end of the yellow wire (hidden inside the harness plug) to reach the bare metal end of the yellow wire. Touch the probe to the bare metal end of the yellow wire
4. Turn the ignition to the ON position but do not start the car.
5. Read the meter display. You should see a voltage reading between 1.19-1.31 volts. Write the voltage down.
6. Now re-install the GT-500 throttle body and repeat steps 2-5.
7. If the TPS voltage on the GT-500 throttle body varies from the stock TPS voltage then follow the next steps to adjust the GT-500 to stock settings. This is easily done with the throttle body bolted to the car.
ADJUSTING TPS VOLTAGE
1. With your meter still connected, loosen the mounting screws on the TPS sensor and gently rotate it until the desired voltage is achieved. Then tighten the screws.
2. Once the desired voltage is acheived, plug the throttle body motor in.
3. Turn the ignition key to the OFF position, then cycle the ignition key from the ON position 4 times to allow the car to "self check" the throttle body and sensors for proper operation.
If the throttle body voltage and senors are correct then the CHECK ENGINE and FAILSAFE warnings should be gone when you turn the key on for the 4th time..

 

[sdtsdt]

Guys, thanks for the responses ... I did not realize that studs were involved at first ... when now looking at the car, i see the studs are in still inthe bottom, but longer screws with allen head are in the top. I discovered that the nut on the passenger side stud is missing. I speculate that this could potentially be a problem if the sealing surfaces are not flush. I am going to replace this nut, torque it appropriately, clear the code, and see if the problem re-occurs. This may be wishful thinking, but replacing a nut and driving the car a day or 2 is a lot easier than swapping units. If the failsafe mode comes back, then I will swap the units ... What do you guys think? Thanks, Steven

 

[stlwagon]

Guys, thanks for the responses ... I did not realize that studs were involved at first ... when now looking at the car, i see the studs are in still inthe bottom, but longer screws with allen head are in the top. I discovered that the nut on the passenger side stud is missing. I speculate that this could potentially be a problem if the sealing surfaces are not flush. I am going to replace this nut, torque it appropriately, clear the code, and see if the problem re-occurs. This may be wishful thinking, but replacing a nut and driving the car a day or 2 is a lot easier than swapping units. If the failsafe mode comes back, then I will swap the units ... What do you guys think? Thanks, Steven

If the throttle body is not sealed you could be getting some unmetered air in there which could be causing your issues.

 

[Mic5rbns]

The BBK required transfer of the TPS and throttle actuator motor from the OEM piece. You'll need to put those back on. Here's a good writeup about a swap to a GT500 TB. The process of checking the TPS voltage is the same.

CHECKING TPS VOLTAGE
To check the TPS voltage you must have a DIGITAL voltmeter.
1. Reinstall the stock throttle body.
2. LEAVE THE THROTTLE BODY MOTOR UNPLUGGED (the small connector on the driver side of the throttle body).
3. Ground the black wire of your meter and poke the probe of the red wire on the meter into the YELLOW wire of the TPS sensor which is the bottom wire on the plug located on the passenger side of the throttle body. You DO NOT need to break the wire to read voltage. The best way to probe the yellow wire is to poke the probe into the plastic harness plug (while it’s plugged in to the TPS). You will need to penetrate the blue insulator the goes around the end of the yellow wire (hidden inside the harness plug) to reach the bare metal end of the yellow wire. Touch the probe to the bare metal end of the yellow wire
4. Turn the ignition to the ON position but do not start the car.
5. Read the meter display. You should see a voltage reading between 1.19-1.31 volts. Write the voltage down.
6. Now re-install the GT-500 throttle body and repeat steps 2-5.
7. If the TPS voltage on the GT-500 throttle body varies from the stock TPS voltage then follow the next steps to adjust the GT-500 to stock settings. This is easily done with the throttle body bolted to the car.
ADJUSTING TPS VOLTAGE
1. With your meter still connected, loosen the mounting screws on the TPS sensor and gently rotate it until the desired voltage is achieved. Then tighten the screws.
2. Once the desired voltage is acheived, plug the throttle body motor in.
3. Turn the ignition key to the OFF position, then cycle the ignition key from the ON position 4 times to allow the car to "self check" the throttle body and sensors for proper operation.
If the throttle body voltage and senors are correct then the CHECK ENGINE and FAILSAFE warnings should be gone when you turn the key on for the 4th time..

Does this procedure work on oem tps.?

 

[stlwagon]

Does this procedure work on oem tps.?

Absolutely! I've used it many times. Just look for a voltage around 1.24 volts.

 

[travelers]

Guys, thanks for the responses ... I did not realize that studs were involved at first ... when now looking at the car, i see the studs are in still inthe bottom, but longer screws with allen head are in the top. I discovered that the nut on the passenger side stud is missing. I speculate that this could potentially be a problem if the sealing surfaces are not flush. I am going to replace this nut, torque it appropriately, clear the code, and see if the problem re-occurs. This may be wishful thinking, but replacing a nut and driving the car a day or 2 is a lot easier than swapping units. If the failsafe mode comes back, then I will swap the units ... What do you guys think? Thanks, Steven

That's a good possable.