Dirty Throttle Plate

[CNCwell]

I have posted on here recently about several issues I was having with my TB. All of them seemed to pop up about the same time and none of them followed the normal cycle consistent with failure of any individual system. Below is a list of the problems,

AC compressor clutch does not engage
Rear defrost does not work
Cruise Control will deactivate when the engine down shifts to speed back up
Gas mileage was averaging about 10.5 MPG

So I hit the internet and started reading on every forum I could find that talked about these issues related to a TB. The common theme I found was that the PCM on these models is adaptive. (It doesn't appear that this was intentional, it appears that this is a side effect of the coding) When the engine begins to idle differently than it was designed to, the PCM starts to drop functions it deems unnecessary. I read on one of the forums that most if not all of these issues can usually be cleared up by a thorough cleaning of the throttle plate.

I removed the throttle plate and found that it was completely caked with muck. The picture below shows the back side of the throttle plate after I started cleaning it. (I didn't have the foresight to take a picture prior) I used a rag and carb cleaner to get all of the crap out and then re installed the throttle plate. I then unhooked the battery to allow the PCM to reset.

Once I started the TB I could immediately tell that something was better. I took it on a trip to Lexington that is 140 miles round trip. I averaged 15.5 MPG and had no issues with the cruise control. I had fewer shifts during the travel with the CC engaged and my transmission temp stayed below 200 degrees. (It had been hovering around 230 degrees). The AC clutch still will not engage but I did find the next morning that the defrost now works. All in I have 45 minutes and $5.04 invested in the cleaning. This may common sense to some but I hope this helps anyone looking for a cheap fix to some common problems.

[TBYODA]

Good work and I am sure the plate was much worst but I'd suggest removing again and scrub with a old tooth brush and the cleaner to get totally clean. Also so you don't possibility damage any HVAC actuators by removing battery, you can pull the PCM fuses 10 PCM b & 28 PCM 1 in the front fuse box for 15 min. If you have now come accrues this youtube channel he got some good videos. He is member of on GMTNATION by the same name.

http://www.youtube.com/user/may03lt

[CNCwell]

I will do that now! Thanks for the feedback.