1jzgte, Single turbo, vaccum issue
04-13-13, 08:21 AM
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1jzgte, Single turbo, vaccum issue
i'll start by saying, i have searched and couldn't get a clear answer. Also i couldn't get the link in the sticky to open for some reason. I found vac diagrahms online but they were in japanese...
and i'm a redneck.
i'll try to be as clear as possible.
the car runs, and i can drive it. i have a build thread here. I realized there was a issue after i got my wideband and boost guage hooked up. The guy who originally did the swap didn't pay attention to the vac/boost (no guage when i bought it) and when i dumped the twins and went single i exasperated the issue.
I haven't touched this setup but something seems fishy, why would there be a capped port
Port #1 - capped
Port #2 - runs to port #6
What is correct for these two? pre or post throttle body sources?
Port #3 - directly to my MAP
Port #4 - this thing is tricky, i havent seen it in any vac digrahm... directly below port #3 is where the vac line for port #4 comes from. I can only follow it back to underneath the throttle body and am not sure of its source or where it was supposed to go.
Port #6 - should be capped based on every picture i have seen. But this guy originally ran it to port #2.
Port #5 - if this port is open to the atmosphere, it will drop idle to almost stall. The pictures i have seen show it going to pre-compressor intake, is this correct?
Symptoms:
Iratic a/f at idle (depending on current vac setup is if it lean or rich) usually rich.
Vac leak, only showing 10hg at idle (standard should be 18-20 correct?)
Iratic idle, low or high depending on current vac connections.
i'm literally at a lose, any help or ideas would be awesome. Its depressing when your car is down
it makes you have horrible thoughts and wish for other cars lol
help me enjoy my girl again
ps- i know my spelling is horrible, suck it lol
and i'm a redneck.i'll try to be as clear as possible.
the car runs, and i can drive it. i have a build thread here. I realized there was a issue after i got my wideband and boost guage hooked up. The guy who originally did the swap didn't pay attention to the vac/boost (no guage when i bought it) and when i dumped the twins and went single i exasperated the issue.
I haven't touched this setup but something seems fishy, why would there be a capped port
Port #1 - capped
Port #2 - runs to port #6
What is correct for these two? pre or post throttle body sources?
Port #3 - directly to my MAP
Port #4 - this thing is tricky, i havent seen it in any vac digrahm... directly below port #3 is where the vac line for port #4 comes from. I can only follow it back to underneath the throttle body and am not sure of its source or where it was supposed to go.
Port #6 - should be capped based on every picture i have seen. But this guy originally ran it to port #2.
Port #5 - if this port is open to the atmosphere, it will drop idle to almost stall. The pictures i have seen show it going to pre-compressor intake, is this correct?
Symptoms:
Iratic a/f at idle (depending on current vac setup is if it lean or rich) usually rich.
Vac leak, only showing 10hg at idle (standard should be 18-20 correct?)
Iratic idle, low or high depending on current vac connections.
i'm literally at a lose, any help or ideas would be awesome. Its depressing when your car is down
it makes you have horrible thoughts and wish for other cars lolhelp me enjoy my girl again
ps- i know my spelling is horrible, suck it lol
04-16-13, 05:04 PM
#5
port 2 is an air breather, it goes to open air and has a cap with a small filter on it.
port 1 goes into the intake manifold.
port 3 with the gas filter is for the map sensor
I wanna say port 4 is for the evap system so run it to the charcoal canister or cap it off but I've only worked on 1 1jz so...This is a mark 3 diagram so idk how accurate it is for the sc300.
port 1 goes into the intake manifold.
port 3 with the gas filter is for the map sensor
I wanna say port 4 is for the evap system so run it to the charcoal canister or cap it off but I've only worked on 1 1jz so...This is a mark 3 diagram so idk how accurate it is for the sc300.
Last edited by account2x; 04-16-13 at 05:11 PM.
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04-17-13, 06:50 PM
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i made a video. the map signal was split x4 places, it is now one straight line. idle a/f is now stoich! still idles low.
i know its not a fuel filter lol
after hooking the boost guage back up i am now showing a -15hg at idle... small leaks are harder to find
soooooo what do you guys think is causeing low idle? could a -3hg to -5hg leak cause that much of an issue at idle?
ps- thanks for the help
04-18-13, 05:29 PM
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@solid, i actually replaced ALL the lines. even to PS and FPR. I am going to make a boost leak tester instead of borrowing my friends again (for hours at a time) and try to figure it out. Hopefully if i get the leak fixed the idle will come up.
if not, what else causes low idle?
if not, what else causes low idle?
04-26-13, 11:38 PM
#12
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Off topic question, but how did you mount your gauges? I'm looking to mount mine EXACTLY like that lol. I also have a AEM wideband and boost gauge that I'm relocating.. Thanks in advance!
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