Big vaccum leak...........but where

[Florida240sx]

I used duct tapt to make my own boost leak detector.I cannot figure out where the actual leak is.It's blowing from the TPS sensor or off it... The throttle bodt wasn't removed and everything is tight. The idle air control valve pipe isn't leaking.It almost looks like it is coming through the tps itself...What is by the throttle body that could leak?? Any other ideas on what I could spray on it to source it? Right now I'm using tire foam.

[SeVa-S13]

Here's a link to pic I took of mine when I did the gaskets recently; it shows the underside so maybe that'll give you ideas? http://nissaninfiniticlub.net/...7.JPG

Oh, and I always just used sopay water in a spray bottle,

[j-z]

what does your motor act like while running?

[Florida240sx]

Being I got the leak my a/f ratio is rich at idle. Can barley drive it. Starts cutting out unde rload until I get going. Had it in 3rd gear cruising and had 2-3lbs of boost built up. I said what the hell and went half throttle, car slowly picked up and then as soon as rpms hit 3800 car got quite, then at 4k it threw me into the seat, this was at half throttle. Everyhtign seems to be working great, just got to find this leak. Somehwere in the front by the TPS. Only air vaccum line is the IACV correct??J-Z your car running good now??

[rotorimp]

Was that thing at the bottom of the OCEAN? the area around the TPS looks corroded. Soap and water will find leaks under pressure not vacuum. You should be in vacuum at idle. try spraying a -->LITTLE<-- carb cleaner around and see it it revs up-that should find you leak.

[j-z]

he made a pressure tester meaning everything is under pressure and not vacuum, so the soapy water is the best trick. but for finding leaks while the motor is running some carb cleaner will do the trick. i think i should make my own pressure tester as thats a real good idea. and justin, my car is just sitting there. i havent even looked at it since i got it back. i grounded the motor out to the chassis and got the starter to turn the motor, but she doesnt fire. it hasnt fired ever since i moved the maf to my turbo inlet and before the iacv. i think im just gonna weld a nipple onto my cold pipe for the iacv and put my maf back in the cold pipe where it used to be and go from there. its been too hot out to do anything to it.

[Florida240sx]

Maybe I can come over sometime this week and troubleshoot. Carb cleaner won't work. I know the location of the leak but can't see it. It's behind or across from the tps. Just don't undertand where it's from. Doesn't feel liek it's from the block, but doesn't feel like it's from the throttle body....For my boost leak tester I just used duct tape. Took off my turbo coupling, put duct tape across it then put in the air compressor nipple and then squeezed the coupling for a tight fit while pumping air into the system...

[rotorimp]

Can't you pick up another TB?

[Florida240sx]

I got another one in my garage.Doesn't make sense because it was never removed.... Going to look at it in a few minutes again..

[j-z]

yeah man if you want to come by sometime during the week its cool with me. i could use an extra hand on this part now. my email is [email protected] if you wouldnt mind coming to help.

[Florida240sx]

I'll swing by sometime this week or be there this upcomign weekend, whichever works out. Wish I could find this damn leak...Ready to take the mani off my other engine....

[j-z]

cool man i appreciate it. hopefully you can find out where your leak is coming from. maybe try swapping TBs from your vert and see what happens.

[Florida240sx]

I got my spare motor in my garage..I'll report back in about an hr...Going to go tinker....

[Florida240sx]

Found it...But now got other issue...

[bassman31386]

so where was the leak? i had a similar problem when i tried to pressure test to check for leaks. I never found where it was coming from, although my car idles fine but it fluctuates between pulling anywhere between 10 and 17 in-Hg vacuum. Also, it accelerates quickly up until ~3000 rpm, and then rises very slowly after that (MAF is good). This is a NA engine btw.

[rjlong140]

What manifold are you using? If stock, what did you do with the PCV hoses? If they crack, you could be loosing boost there; kind-of close to the TPS.