GSR jsrc & vaccum at idle

[randomwalk101]

I'm just curious of what is your VACCUMN reading at idle?

My GSR with 6psi and now with Endyn pulley (reads 9.5psi now w/ test pipe on) is only at -20. Of course, the car is quite old...1995 with about 155,000 miles (55,000 miles on JRSC?).

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It's powered by GASOLINE damnit!!!

[DC2 GSR]

I just saw a post from "Klintman" stating that idle vacuum should be between 30-35 psi.... is this right? Mine sits at around 21-22psi but I know I have a vacuum leak somewhere after the TB... could this be decreasing my vacuum by that much? If you know how to accurately trace a vac leak, please read below:

Sorry to bud in on your thread here... My idle is constantly over 1300rpm but if I spray quick start under the intake manifold from the passenger side of the engine, the idle drops like it is going to stall and then shoots up again.... any idea where the leak could be originating? Shoud I put sealer on all of the gaskets between the TB and Head?

Thanks

Ian

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1994 GSR
JRSC

[NeedToGoFASTER]

At IDLE (750 rpm) mine reads about -17 to -18 psi.. I have a small vac leak though, but it read about the same before the leak happened anyway.

Richard

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98 GSR driven everywhere.
Akimoto intake, MSD 6a, Magnecor 8.5mm, Autometer A/F,Boost,F/P, B&M F/P, NGK BKR7E, JRSC, JR MAP Mod, Walbro GSS-342.
Ex-Squeezer.
Open Import Fuel Tuner

[NeedToGoFASTER]

Ian,

Your vacuum leak sounds like it's coming from the same general area where I found mine.. In my case, one of the four allen bolts which holds the bypass valve thingy onto the intake manifold had fallen out.. I hacked it back together and called JR to get the bolt size.. Someday I'll tear it apart and put it back together correctly.

Richard

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98 GSR driven everywhere.
Akimoto intake, MSD 6a, Magnecor 8.5mm, Autometer A/F,Boost,F/P, B&M F/P, NGK BKR7E, JRSC, JR MAP Mod, Walbro GSS-342.
Ex-Squeezer.
Open Import Fuel Tuner

[falconGSR]

my autometer reads between 18 and 20 inches of vacuum. with or without the SC. we should all read our MAP sensor voltages at idle. that would be more accurate and we would be using identical 'gauges'.

Joe


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Boost. Finally.

[randomwalk101]

Hmm...I have never seen a 30-35psi vaccumn on jrsc before.
As for vaccumn leaks, I dont' really think it's the case..because if you do, your idle will fluctuate. I had a vaccumn leak like you guys described before..and it turned out to be around the PCV valve. Plugged the new PCV valve in place and the problem was solved.

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It's powered by GASOLINE damnit!!!

[justa4]

Most places consider good vacuum to be anywhere form 22 to 16 at sea level but the higher you go the lower the number will get but I forget how much.
I have my boost gauge tapped in between the fuel pressure regulators and it reads -18 but if I take it off the TB I get -21 but no boost. Anyone know why it would be different between the 2?

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[bobbrown]

I'm at sea level and my gauge reads 20" at idle. 10" when cruising at 80MPH in 5th (4000rpm). I verified that these numbers were correct with the guys at Jackson.

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[klintman]

smoking too much crack ...sorry . my idle vac is between -20 & -25psi on the gauge .

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99' GSR / JRSC @ 6psi
-JR MAP & BTC
-Walbro 342
-Comptech exhaust & intake/icebox
-Comptech/Koni coilovers
-Mugen 22mm rear sway bar

[klintman]

smoking too much crack ... sorry . my vac at idle is between -20 to -25psi on the gauge .

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99' GSR / JRSC @ 6psi
-JR MAP & BTC
-Walbro 342
-Comptech exhaust & intake/icebox
-Comptech/Koni coilovers
-Mugen 22mm rear sway bar