Gen II Throttle Body Question

jart

New LVC Member
Joined
Dec 9, 2012
Messages
8
Reaction score
0
Location
Indy
I've got a 2003 LS 3.9. Throttle response is really slow, and sometimes it will speed up and slow down while holding the gas pedal steady. All indications point to replacing the throttle body. Has anyone had luck replacing just the TPS instead of the whole unit? Big difference in price.
 
Fresh set of Motorcraft coils and plugs just installed. I had a Ford tech connect his laptop and monitor the TB while we were driving and you could see it open and close on the graph without moving the pedal.
 
Get an old toothbrush and a can of throttle body cleaner and pull off your intake and clean it really good. When I first got my car it felt like the throttle was sticking sometimes, once I cleaned the gunk that had built up around the throttle valve (the big circle that rotates) it stopped acting weird and the response was much better. Granted, to get really good response apparently you need a tune :)
 
...I had a Ford tech connect his laptop and monitor the TB while we were driving and you could see it open and close on the graph without moving the pedal.

This is normal. It's the biggest part of the reason that they went to ETC. It allows them to play with the throttle independently of the driver's foot to get the best gas mileage. The gas pedal is just an input for how much power you want. The PCM decides how to achieve that using throttle position, transmission gear selection, ignition timing, and so on.
 
This is the first LS I have owned or driven. I thought the throttle response was terrible but after some research, it is a common complaint and so I figured it must be normal. However the tech that drove it has driven and worked on several Gen II LS's and his comment was "WOW this thing is crazy" Also the involuntary throttle fluctuations were not suttle adjustments but 50 percent swings in open and close.
 
I cleaned the throttle body and that cured the problem completely. Now it has very good tip in throttle response and no more rattle on acceleration. Thanks for the tips...
 

Members online

No members online now.
Back
Top