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3.8L Throttle Body help


ssjones
03-25-2006, 11:59 AM
I'm hoping someone with a 3.8L has had experience removing the throttle body (on my '94 LeSabre).
See relevant thread information at:
http://www.automotiveforums.com/vbulletin/showthread.php?t=542590

Any help appreciated, that TB has to come off for the new Throttle Position Sensor.

wrightz28
03-27-2006, 11:33 AM
You shouldn't have mess around with any exhaust bolts, for a throttle body :dunno:
I haven't worked on too many series II lately, but I don't ever remember having to remove it either for TPS. I remember it's a tight fit, but nothing crazy ti do?

mrfix
03-28-2006, 08:09 AM
I recently had to remove the throttle body on my 97 PA to clean out accumulated carbon deposits (throttle stuck when first started). After removing the air filter cover, air filter and rubber intake hose, the tb attaching nuts could be removed pretty easily (btw, there will be some coolant that drains out). The lower bracket bolt is in a bad position, but I used a short 3/8" (as I recall) combination wrench, and with some contortions and a few curses aimed at GM engineers, I was able to get it off. It helps if you have an additional joint between your elbow and wrist, but it can be done without major engine disassembly.

flirtypurty
04-02-2006, 07:50 AM
Hey mrfix,my throttle is sticking also,97ultra,what do i need to do to fix it exactly?thx tom

ssjones
04-02-2006, 09:39 AM
MrFix:
Thanks for the reply, I must not have checked the email notification.
I ended up taking it to my local service station. I was able to get one screw off the TPS, but the other was frozen and broke off. More cursing ensued as I tried again to remove the TB. Sadly, I did not purchase the stubby wrench set that was in my hands twice this year! The tech at the service station (owned by a friend) used, yep, a stubby wrench for that bracket bolt. I contemplated hacksawing off the tab ear, but was so frustrated, just took it up to the station. He had it off in a few minutes and EZ-outed the broken fastener. I had purchased the proper cap screws to remount the TPS unit vs. a phillips screw head. He used those so subsequent changes will be easier.

mrfix
04-03-2006, 08:26 AM
I really don't know much about the supercharged version and how it might affect this procedure. Assuming there is nothing related to the blower that needs to be removed, this should work. After removing the tb as outlined in the previous post, use some carb cleaner and a stiff bristle brush (I used an old toothbrush) and clean out as much of the carbon deposit as possible. Pay special attention to the circumference of the throttle plate and its mating surface on the body itself. This worked well for me and it didn't require any disassembly of the throttle shaft, plate or the position sensor. If you use care in the removal of the tb, you shouldn't need a new gasket. It appears to be a special o-ring type gasket. It's a good idea to check it to make sure it isn't damaged, though. Remember that you are going to get some engine coolant leaking out. Hope this helps.

ssjones
04-03-2006, 08:30 AM
We put on a new gasket as I had already purchased it, $5 locally. The o-ring style gasket was in fine shape. Not much carbon deposits either. I use TB cleaner once a year, looks like that paid off. Car is running fine once again. I am curious to see where that extra vacuum line is supposed to attach.
http://community.webshots.com/photo/548873230/2007247980062237293LYtGPC
http://community.webshots.com/photo/548873230/2221468220062237293CCgztI

mrfix
04-03-2006, 08:45 AM
On my 97 there are two vacuum lines from the tb. One is pretty skinny and the other larger. The skinny one goes to, what looks like, some sort of vacuum actuator attached to the fuel line (manifold?) close to the tb. The larger one goes to some sort of pneumatic/electric device toward the front of the engine close to the first cylinder. Not sure if my descriptions are clear, but I hope this helps.

ssjones
04-03-2006, 05:32 PM
My '94 has a 3rd line. I posted on another forum, a guy with a '94 replied, hopefully he can help me identify the locations. His first reply was that it was definitely for the cruise control function. That makes sense, since I had a cruise control code.

jag_man653
04-05-2006, 01:43 PM
I'm hoping someone with a 3.8L has had experience removing the throttle body (on my '94 LeSabre).
See relevant thread information at:
http://www.automotiveforums.com/vbulletin/showthread.php?t=542590

Any help appreciated, that TB has to come off for the new Throttle Position Sensor.

I recently replaced the TPS on my '95 PA Ultra. I removed the EGR valve and the thermostat housing to get at the TPS screws. Not at all difficult. I didn't bother the drain the coolant, but left the cap on, so there was some coolant loss but not much. It ran down and apparently collected in the exhaust crossover heat shield, causing a lot of white smoke when it warmed up the first time, but no big deal.

I haven't had the TB off.

Ed

ssjones
04-05-2006, 07:44 PM
Ed:
I got one screw off by removing the thermostat elbow, but the other was frozen in place and eventually broke. I put back in hex-head bolts that will be easier the next time (hopefully these sensors outlast our ownership!)

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