Does a bad throttle body position sensor throw codes anytime it's bad?Or could it be bad and not throw codes? I'm not getting codes but suspect it may be bad. I'm going to test it this weekend.

 

You should get a code. Have you tried reseting it (disconnect the battery for 5 minutes)

 

You could have a bad spot in it like a volume pot on a old stereo and basically it
would send noise to the comp. just like it does to your speakers. They are basicly
the same thing. You can test it with a DVOmeter and see if you are getting a
good smooth sweep. I never replace anything unless it actual is bad and tests
bad on either the self test or with a multimeter!! If you swap it out and disconnect
the computer(you should when working on it) then if say another component is bad
not the tps, Well your computer is going to relearn it's settings and now it is going
to take the bad signal from whatever else was bad and make it's tables with that.
It will take along time for it to realize that component is bad and during this time
you could say be running rich so that is going to carbon up your combustion chamber
catalytic convertor etc. and then you are going to have new problems and the cause
may get overlooked again and again since the problem has now become a different
problem!! A $15.00 multimeter can save untold amounts of money. Don't unhook
your computer to clear codes unless you have replaced the actual bad component
it can cause more problems then it solves and may only be a temporary fix t the most.

 

Yeah I tried that. In 3rd and forth gear (e40d) i've got a little miss during part throttle at around 1500-1700 rpm. The truck will accelerate but not as smoothly as it did. It's part throttle acceleration, not part throttle cruise. For example, , going 70 on a slight incline, my truck used to not downshift. Now it misses a little, downshifts, comes up to speed good. Around town if I'm going 35 in 3rd gear and I need to accelerate in misses a little. It will speed up but it misses. It seems any time i am holding a certain speed and need to speed up alittle it does it. All typical tune up stuff has been done. I also replace the 02 sensor last week due to 172 code and bad skipping. EGR is disconnected. Timing is 10 btc. Any suggestions? I also get the start, stall sydrome upon first cold crank up.

 

Hey blue beast, I've got a volt meter and I'm going to check it this weekend. That was a great example about the stereo. Thanks for your response

 

That is also a symptom of water in the fuel and 2 bottles of heet and 2 of iso heet
may cure it!! I would dump it in on whatever is in there and run it until 1/8 tank or
so and see how it does with a fresh tank of fuel. If you wanted to be sure to get
the heet on the injectors remove the fuel filter and fill it with heet then reinstall
and bump the key a few revs to get the heet onto the fuel rail and let it sit.

It is like $6.00 and worth a shot and should be run a bottle every other oil change
since with gas prices the way they are not many people are filling up all the way
and all the empty space in the tank is condensing moisture out of the atmosphere
and then the first splash it is in the fuel, and the moisture is also causing scale
rust to happen on the metal components and the tank if it's metal. Which is not
good for the fuel system as a whole since if it is small enough to make it past the
filter it is essentially like tiny little razor blades and your injectors, fuel pumps are
getting media blasted by iron oxide!!

 

I checked the tps and it checked out good. I'll try the heet.