Throttle Position Sensor

[iriaf2001]

The TPS on my GSX is bad, I installed a Throttle body from a 1994 Eagle Talon with 4G63 motor. Though its a direct fit the TPS from that car is not the same. Idling is erratic. But the car is drivable with no Check Engine Light and no stalling....problems I experienced with the original Throttle Body and TPS installed. I confirmed the TPS is bad by getting the Diagnostic Codes. My question is can I take a Throttle Body from another Galant GSX that has an Automatic transmission and install it on my GSX that has a manual transmission. I was told that the TPS on a GSX with Automatic Transmission may be set\adjusted differently or it may be a different part all together. Just trying to do a direct swap and avoid adjusting a TPS. Any help is greatly appreciated. Thanks!

 

[stevep]

Did you set the TPS when you installed the TB?
Why are you swapping the whole TB to fix a TPS problem?
What year GGSX?

 

[Hertz]

Did you clear the code/reset the ECU?

 

[iriaf2001]

I did not make any settings changes to the TPS. I was hoping to avoid changing the factory set positions of the TPS on the TBs so I just swapped them. This also gave me the chance to thoroughly clean the TBs. Its a 1990 GGSX. I found a GGSX at a junk yard with 108000 miles and the engine is still complete. I was hoping to buy the TB off it but its an Automatic trans GGSX. I thought the issue with my GGSX idling high(1200-1300RPMs)was because I installed a TB from a Talon that also had an Automatic trans, maybe the TPS settings are different?...maybe set to idle a little higher to produce the power needed to turn the auto trans' torque converter? Im just wondering if I will see the same issue on the TB from the junkyard GGSX? Can I just adjust the TPS settings instead...even though its from a Talon? Applogize for too many questions, my 4G63 experience is very limited and i really hope to learn alot from your experience. Thanks.

 

[iriaf2001]

Yup, I cleared the codes by unplugging the battery for several minutes. After that no more codes(this is after installing the TB from the Talon). If I plug the original TB with the original TPS back on I get the Check Engine Light and the codes result in a faulty TPS.

 

[Muskrat]

1st check that your ISC motor is good per VFAQ.

If that checks ok then check the TPS, per VFAQ. (You can also use a datalogger and set to 10%, instead of checking resistance with a multimeter. either way works)

If the ISC is bad replace it. If the TPS isn't adjusted correctly you need to remove the TB to adjust it (you need to to get at the bottom screw).

If that's all set correctly you'll have to look elsewhere for your idle woes. Maybe try a boost leak test. What is is actually doing? (aka erratic idle can mean a lot of things. describe the actual symptoms)

Good luck!

 

[iriaf2001]

When first starting, it idles at around 600-700rpms, though there are times it stalls when I first start it. Once driven and engine is warm the idle is around 12-1300rpms while at a traffic light or while switching gears. I adjust the idle screw to lower the idle rps while the engine is warm but when I start it again the next day for example it just stalls.

 

[iriaf2001]

Fixed! I installed the throttle body from a 1991 Galant GSX I found at the local junk yard. Idles great now! And no need to mess with any of the factory settings. Thanks everyone for your input.

 

[Muskrat]

Ok, so you're car runs. Cool. What was actually wrong? You didn't really learn anything. And instead of just buying 1 part, you had to buy 2 different throttle bodies.

What are you going to do if it starts having issues again, just start changing out T/B's until it works?

There's something to be said for going through the proper diagnostic steps. And you'll learn a whole lot more that way.

 

[iriaf2001]

I did go through the diagnostics tests. I used an analog multimeter to get the engine codes. Thats what lead me to the bad TPS on the Throttle Body. I actually only bought 1 TB, the other two I already had, one from the original blown 4G63 that was replaced and the other from the 4G63 I harvested out of a 1994 Talon to install on this GGSX. I used the multimeter to check the resistance of the TPS, and the voltage going to the TPS. The procedures I found on a document from this forum, very helpful. After checking the resistance the TPS was actually bad causing the check engine light to illuminate and the idling to be erratic. A new TPS was very pricy, about $141 at RockAuto, so I tried installing the Throttle Body from the 1994 Talon. It was a direct fit but the idling was still not right, it idled very high at 1200-1400rpms, when looking up the part numbers for the TPS, RockAuto and even Autozone listed a different part number for a 1990-91 Galant GSX and 1994 Eagle Talons. The settings for the Talon TPS may have been different than that of the GSX since the Talon was originally Automatic Transmission but I was not sure and this was one of my questions. I could have readjusted the settings on the TPS to match the settings indicated on the manual for the GGSX but I wanted to avoid changing any of the factory made settings in case I needed that Talon TB for an actual Talon. Since a GGSX was available on the junkyard I went down, took my multimeter and did a quick resistance check, it was good, so I took a gamble and bought it, it was only $35 for the whole TB.

Sorry, I know I didnt post what I did here initially but my main question was if there is a difference in TPS for 1994 Talons and 1990 GGSX and if there is a difference on TPSs installed on Auto trans and manual trans. So what did I learn? Well so far it seems a TPS from 1994 Talons may not work properly on a 1990 GGSX wihtout readjusting the TPS. This is my first GGSX so Im learning alot from all of you and this forum! Thanks.

 

[Muskrat]

Fair enough.

I was just a little peeved because it sounded like you came on here asking for help, then just went out and ignored everything everyone said, and tried a new T/B.