I'm assuming my car has a vacuum leak but wondering if it could be anything else.

It will sound like its misfiring and the idle will drop down , the more I try lowering my idle the more it does it

The car has a freshly rebuilt.engine with literally 0 miles, its only been idled and revved in neutral to stay running.

I have an exhaust leak at my Turbo to down pipe because my down pipe had crap weld job and the welds are blocking.the nut from being torqued fully.

I've went.through the uim and everything around it , next ill do.the lower manifold.

Rotary > Pistons

 

Almost always vacuum leak, followed by incorrect vacuum wiring, followed by out of adjustment TPS, and then of course, low compression.

 

what do you mean by incorrect vacuum wiring, I've blocked off everything and put vacuum only to the few things needing a vacuum source.

the only thing that could be leaking is the block to lim, I do hear a hissing sound coming from somewhere near the firewall , my friend said its the brake booster.

I'm gonna try the Carb cleaner trick and see if that helps me find the leak

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Just a list of the most common culprits. Vacuum lines being incorrect is a common one. Is this a TII or an N/A? With everything removed, how did you cap/close the various remaining vacuum ports? Caps can be a very common source of leaks. Did you use any kind of sealant (hylomar, etc) on the gaskets? Are they new/reused?

I've had mixed results with the carb cleaner trick. For small leaks it can sure be a pain. I've become much more fond of compressing the entire intake track if you have a compressor available. Much faster.

 

its a Turbo and I blocked stuff by looping hoses from nipple to nipple, vacuum caps for small ones I couldn't loop , and this sounds ghetto but spark plugs to block the bigger hoses that I had no other way to block.

I didn't have hylomar and I do have a compressor but pushing 120psi through the intake could damage something couldn't it? I'm not sure how much pressure the manifolds see but I didn't think it was that high.

I used ultra black rtv, however I did use anti seize on my bolts and later read it was a bad idea but I asked friend Brian at bdc and he said it'd be fine.

so idk what to do, I was gonna redo the lim and go over it all.

from what I.learned the gaskets self seal on OEM gaskets, though my lim gasket is from Atkins.

all the gaskets are new, all the hoses are new.

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how well did you seal the acv block off? did you adjust the tps? any doubts on seal of acv redo it the plates sometimes leak. ADJUST THE TPS.

 

I put ultra black rtv all along the edges though I could do it again to be sure

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Your air compressor doesn't have a regulator on it? I have a pvc cap a nipple on it that I use to check for leaks on my old legacy that I once owned. Turned the regulator down to about 20psi and checked for leaks.

 

I think mine is broke I bought it used

Rotary > Pistons

 

Exactly. Regulator and PVC adapter = win for finding vacuum leaks.


Make sure you didn't loop any vacuum/boost sources into the pre-throttle plate fresh air sources.

Do you have a stock or aftermarket turbo inlet duct? Either way, make sure there are no leaks between the AFM and the turbo. Everything else sounds fine. For the LIM, even though the gaskets "should" seal without any prep, I'll put a thin film of RTV on the gasket, much in the same manner as hylomar. The idea is that the RTV isn't making the gasket, just helping the seal. That usually takes care of any manifold issues I have. Have you plugged/sealed the OMP or still using the standard injectors? If they're still installed, are they connected to the vacuum nipples on the intake manifold or open?

 

stock tid, omp blocked , oil injectors blocked.

everything seems like it should be fine maybe I need a good way to find the problem , the compressor way sounds good if I could somehow lower the pressure.

I could by regulating it myself by shutting off the compressor and letting air out until its at 20 psi, I don't have a PVC adapter though

Rotary > Pistons

 

You can find em at home depot or a hardware store. Just any PVC cap that will fit in your inlet duct. Just drill a hole and thread in a fitting to attach your compressor hose up.

Look for cracks/leaks in the TID. They can be a PITA.

Something I always try on a car that won't idle that low is gently holding the AFM flapper open while dropping the idle. It takes a bit of tinkering to get the amount just right, but if I can make a car purr like that it usually leads me to believe it's vacuum related.

 

They sell in line regulators if you have to get one. Also the PVC cap can be bought at Lowes, Home Depot, or where ever you buy pluming supplies. But yea, don't forget the squirt bottle with soap and water

 

how were the seals for the injectors?

 

the tid does have a crack where the clamp goes onto the Turbo its maybe an inch long, I figured the clamps squeezing force would seal it

also I didn't mention, car has rtek 1.7 if that matters and a blitz bov

injectors were cleaned and flow tested. came out with very high ratings , higher than the stock ratings

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Rotary > Pistons

 

Might be a good place to spray and see if any unmetered air is coming in. It's going to be a pain, but unless you can do the pressurized leak finder, you're going to just have to work at eliminating options one at a time until it's found.

 

sure enough sprayed the tid where it clamps to.the Turbo and she idled.right up. time for a new tid

Rotary > Pistons

 

the tid where it clamps to.the Turbo it seemed like it slightly idled up.

I also spraying the egr blockoff and manifold to block seemed to bring up the idle slightly momentarily.

how much should the idle go up when yo spray the leak?

 

This.

He didn't ask if the injectors were cleaned he asked how the seals were, you know the rubber grommets that seal them onto the manifold? Those jerks can leak air like a **** if you aren't careful.

 

wouldn't those have been replaced when they were cleaned and all?

also how hard is it to remove the lim with the Turbo still on?

I think ill have to take the Turbo off.

ill prolly get the cork sport tied to eliminate that as a leak
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can over torquing cause gaskets not to seal? or torquing in the wrong order. I torque everything tight until it can't tighten anymore or stop torquing when it keeps spinning and seems like anymore torque will break it (this happened on my split air pipe block off plate)

Rotary > Pistons

 

Didn't you install the serviced injectors? If so, it's incumbent upon you to make sure they were installed properly because even if the grommets were brand new does not mean they will seat properly when installed.

 

I put them in and they seemed to fit just fine with one oring/grommet on bottom, two was too much and didn't fit right

Rotary > Pistons

 

I'm likely going to reinstall everything and be more meticulous about everything

Rotary > Pistons