yurizx6r

Hey guys, I did a boost leak test on my 5.0 and I could not even build pressure to 1 PSI!!! It's leaking bad from the top of the throttlebody/where the TPS sensor is. I have a 70mm Professional Products throttle body... does anybody know where to find a rebuild kit? There is some other leak near the manifold, but I cannot tell for sure where it's coming from until I fix this one.

mjr46

get a new tb....they don't sell rebuild kits...also fyi all tb leak from the throttle shaft a little, even new ones

yurizx6r

If they all leak then how are turbo setups supposed to hold boost? I could not even get to 1 PSI on my boost leak test because so much air was coming from the tps sensor...

What's really weird is that she is running fine! I had no idea I had any kind of leaks until my buddy talked me into a boost leak test. Granted the idle did go up and down like two days ago, but as soon as I put my foot on the gas and let off it was stable again.

jthorn9

As stated, if it's leaking from the TPS valve itself and not the gasket then you need a new throttle body. Depending on how long you've had it, I'd call the dealer you bought it from to report the problem to see if they can give you a new one under some kind of warranty.

mjr46

because they don't leak bad and fast enough to drop boost that fast.......smoke test a new one and you'll see what I mean, even carbs leak a little around the throttle shafts, no way to get a 100 percent perfect seal there on this style stuff

yurizx6r

So I called Professional Products for a rebuild kit or them to take it in and refurbish it. I'm waiting on a call back from them tomorrow to see what they can do. In the mean time I called BBK and they said they have a 1 year warranty on their throttle bodys, so that's good worst case. Both BBK and Professional Products said their should be no leaks and they do not sell a rebuild kit.

I was driving it tonight and the bastard stalled on me when I was coming up to red light. It started back up, but the idle went up and down like crazy, and it wanted to stall again. I had to punch the gas and cut some poor bastard off in order to get it to my friends house ASAP. It just so happens that last week I ordered a Motorcraft IAC because I thought that was the problem. I put that thing on the second I got to my buddy's house, and drove it home with no issues. Weird.

yurizx6r

I called Professional Products again today to see what the follow up was on a rebuild kit. They said they could not give me a rebuild kit, but they could give me a discount on a new one. I told them that per your guy's recommendation I was willing to buy a new one, and also what has been happening with the stalling (happened more than once) and the boost leak test. They decided to warranty it! I was stunned to say the least because I bought it over 2 years ago, but they were EXTREMELY nice about it. The lady said that she felt bad that because their product failed and that put me in danger, so she would take care of it. So I guess if anybody is looking for a throttle body, check them out because their customer services representatives are very nice (long wait on hold though, but worth it). Up until this point I have not had a single problem with the throttle body and just because seal went bad I'm not going to judge them on their craftsmanship. I will follow up with how the new one works out on the boost leak test when I get it.

yurizx6r

I got the new throttle body, and immediately did a pressure test on it before I installed it in the car, no leaks. I am going to install it today, do a base idle/TPS reset, put the new motorcraft IAC on it, and look for more leaks. I am hoping that this has been the problem with the voltage meter I have been chasing for so long. I suppose if it had a vacuum leak that bad along with the piece of crap BWD IAC, perhaps when there was an extra load it voltage wise the IAC was already adjusting for the vacuum leak so much that it couldn't compensate for the A/C, headlights, radio, and break lights. I guess I will find out.

yurizx6r

I installed everything and did a boost leak test... perfect! It immediately started building pressure, and it held at 15 psi! I took it for a test drive with everything on (radio, vents, headlights, etc.), and it did much better with the voltage meter. It also didn't smell as much when I started it and let it idle, so I'm guessing this was a bigger problem than I originally thought. I think I finally found the ghost I've been chasing for a few months now. lol