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-   -   Big vacuum leak that I cannot find (https://www.miataturbo.net/supercharger-discussion-38/big-vacuum-leak-i-cannot-find-100300/)

Jacob Yeager 05-31-2019 06:01 PM

Big vacuum leak that I cannot find
 
I have a 95 with a brp m62 scThat I just put on. And I am having large issues with vacuum. The car idles at about 2000 RPM. It currently has an ms2pnp and an intercooler set up out the front and it’s running an FR gauge and a boost gauge.

The boost gauge reads about 0 hg vacuum. That’s bad.

Ive tried changing the tune and limiting/closing the idle control valve. Also I have gone through the engine and sprayed carb cleaner at what I think is all areas a leak could be. (Intake manifold, injectors, intercooler couples/pipes.) There has to be something that is super wrong but I can’t find it.

The car had a leak when running before the intercooler too..
I know the piping after the sc is ugly but I have PS and AC so it’s the only way I can run an intercooler. At least with the 2.5in pipe I have.

any ideas on what could be happening?

https://cimg3.ibsrv.net/gimg/www.mia...ff63d06f3.jpeg

Holdor 05-31-2019 06:44 PM

Check behind the intake manifold, there is I believe a 3/8 vacuum plug. Due to age these can crack and leak. Did you use a new gasket at the throttle body and cleaned any old gasket off completely? Double check your vacuum lines and that they are routed properly. I'm not familiar with the mp62 but some of the lines in the photo look suspect.

themonkeyman 06-01-2019 12:07 AM

Could have a broken brake booster diaphragm, maybe cap the booster line and see if it changes?

SpartanSV 06-01-2019 01:37 AM

Log and tune please.

Mostly I want to see how you're showing zero vacuum and idling at 2k.

Also posting multiple threads for the same issue will get your ass banned in a hurry.

gooflophaze 06-01-2019 02:08 AM

Throw another throttle body in place of the dummy. That'll determine if it's engine side or supercharger side. Smoke test the rest.

sixshooter 06-01-2019 08:27 AM

It's the hotside valve cover vent being plumbed post throttle.

Fix the pipe/upper radiator conflict before driving it or you will have a bad time.

Is the material of the accordion pipe between the MAF and supercharger fire rated?

BarbyCar 06-01-2019 09:58 AM


Originally Posted by sixshooter (Post 1536981)
It's the hotside valve cover vent being plumbed post throttle.

Fix the pipe/upper radiator conflict before driving it or you will have a bad time.

Is the material of the accordion pipe between the MAF and supercharger fire rated?

Looks from the pic that the vent is plumbed upstream of the throttle - throttle is on the rear of the supercharger.

That accordion pipe looks like the standard BRP supplied hose.

I can't see the idle air or hose - where is that?

sixshooter 06-01-2019 02:20 PM

Open another new thread about the same problem and you will have a new problem.

RunninOnEmpty 06-05-2019 09:29 PM

Where is the blue hose going that's connected on the SC bypass valve? Normally it goes to the nipple you've blocked off on the outlet.

RunninOnEmpty 06-05-2019 09:46 PM


Originally Posted by Jacob Yeager (Post 1536938)
I know the piping after the sc is ugly but I have PS and AC so it’s the only way I can run an intercooler. At least with the 2.5in pipe I have.

I think there's more issue with the pax side IC piping then driver side. I would shorten that coolant hose and replace that piping with a 90* coupler for more space.

Man frottage is all good, but radiator and IC tubes rubbing is recipe for a sad times.


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