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In need of help with vacuum lines with front mount intercool

Posted: Sat Jul 07, 2018 11:32 pm
by Chewysout2play
]I recently purchased a 94 legacy. The owner before me put a front mount intercooler and messed up all the lines I believe. I'm just trying to figure out if anyone can help me. I've looked at the diagram and I can make some sense of it but then I get lost at part. I'm getting a code for the Watergate which the lines are wrong, a code for the iacv I believe and then a incorrect airflow sensor. The codes are 2-4, 4-4,and 4-9.im not sure how to add photos

Re: In need of help with vacuum lines with front mount inter

Posted: Sun Jul 08, 2018 1:38 am
by cj91legss
Photos of your current setup will help us understand what you are working with. What you will have to do is take the pics, upload them to a photo sharing site like photobucket or flickr. After the photos are uploaded they ill give you a link that you can add to your post so we can see what you're wanting to show us. I believe there is some sort of more detailed instructions in one of the stickies on this forum.

Re: In need of help with vacuum lines with front mount inter

Posted: Sun Jul 08, 2018 4:16 pm
by Chewysout2play

Re: In need of help with vacuum lines with front mount inter

Posted: Tue Jul 10, 2018 5:35 pm
by Legacy777
I couldn't get the pictures to work.

Re: In need of help with vacuum lines with front mount inter

Posted: Tue Jul 10, 2018 7:26 pm
by Chewysout2play
Legacy777 wrote:I couldn't get the pictures to work.
Sorry I moved them into a album this should be it now.


http://s1243.photobucket.com/user/Chewy ... egacy%20ss

Re: In need of help with vacuum lines with front mount inter

Posted: Wed Jul 11, 2018 12:17 am
by Legacy777
It's hard to see exactly how things are setup from the photos. I posted the vacuum diagram link in your other post. I would recommend using that and comparing things to what you have to see what may be different.

https://surrealmirage.com/vrg3/vacuum/

What other troubleshooting steps have you performed? We need a little guidance on what you've done so far to help.

Re: In need of help with vacuum lines with front mount inter

Posted: Wed Aug 15, 2018 12:29 am
by Chewysout2play
Sorry it has been a while since i was last one. Had alot of stuff going recently. So far I replaced all 4 spark plugs, spark plug wires and the coil pack. I replaced the mass air flow sensor. I checked to make sure that i was getting fuel pressure to the injectors. I was getting fuel to the injectors. Then i checked for spark which i was getting. So that lead me to believe my issue was with air . So thats why i replaced the mass air flow sensor. Plus since i was getting the code for incorrect airflow sensor. it wouldnt hurt. But once i did that nothing changed and i still have the same code. But im currently in the process of replacing the coolant temp sensor and replacing the iacv with a n/a one since it fits and is the same one just doesnt have the metal elbow for the turbo. I just got a d 90 degree rubber hose and am going to use that to make it fit.

Re: In need of help with vacuum lines with front mount inter

Posted: Wed Aug 15, 2018 12:52 am
by Chewysout2play
i know this isnt the right section and i know u gave me the vaccum line diagram but it isnt for a front mount intercooler. So my only question/problem is how should i reconnect to the original boost soleniod. Where should my line that would go to the intake resonator go. Which would be line j. Then where should line p go also which is the line coming off the charcoal canister to the intake resonator. Because currently my compressor line is on the wastegate actuator. The pressure solenoid is looped onto the boost solenoid. And the line coming off the charcoal canister is just going into the side of the intake and into the pipe of my air filter. If i should move this question to another area please let me know.

Re: In need of help with vacuum lines with front mount inter

Posted: Wed Aug 15, 2018 3:28 pm
by cj91legss
The most important correction I see right off the bat is the vacuum line that is looped from the pressure exchange solenoid (strut tower, brown plug) to the wastegate solenoid. Its vacuum needs to be removed and the pressure exchange solenoid needs to have a line going to the intake manifold. This is likely the cause for your issues.

Wastegate solenoid (the grey sensor under the brown sensor on the strut tower) has 3 ports. Top line needs to go to the turbo wastegate. Middle port needs to go to the compressor housing. Bottom port needs to go to the intake somewhere between the maf and turbo inlet.

Re: In need of help with vacuum lines with front mount inter

Posted: Wed Aug 15, 2018 3:32 pm
by cj91legss
Also your maf needs to be moved. Its just totally in the wrong pipe. If it were me, I would change the intake setup to something more correct and put the maf in there. With where the maf is, it's getting all sorts of incorrect readings.


Edit, sorry I just woke up..., You also have the incorrect maf sensor if your car is turbo legacy and you have the stock ecu. You need the aluminum turbo maf, also found on some 90-91 NA legacys

Re: In need of help with vacuum lines with front mount inter

Posted: Wed Aug 15, 2018 7:20 pm
by nosyt
^^^^ what he said. your maf needs to be pre turbo, currently it is post intercooler right before throttle body.
needs to be
Air filter>maf>pcv lines + bov returned>turbo>intercooler>bov>throttle body

Re: In need of help with vacuum lines with front mount inter

Posted: Thu Aug 30, 2018 11:42 pm
by Chewysout2play
So update after a couple weeks of working my butt off and no time for the car. But i got the intake off. I replaced the iacv with a n/a iacv and put a 90 rubber hose on it so it wouldnt hit the turbo. Then while i had the intake off i replaced the coolant temp sensor. I had to fix the wire to the temp sensor. Nothing was wrong with the wire itself but the outside insulation was a small tear so apparently Subaru doesnt sell pigtail connectors so i spliced the wire and put heatshrink all over the wire to seal the wire back up. After all that was said and done. I put the intake back on and fixed all the vacuum leaks. Also rewired all the stuff that wasnt wired up like cj said. I also didnt read the comments about the maf til just now. But i noticed this when i was putting it all together that it was on the charge pipe and not even on the intake. So i put the maf on the intake so it will actually read the incoming air. Kind of rigged it all up because i had to adjust all the intercooler piping. BUT the good news is i got the car to start and idle by itself . I dont have to wait for it to be warm or keep the motor revved. Also i got rid of the iacv and wastegate codes. But i still had the incorrect sensor code. So i went back to the original sensor which is the hitachi aluminum maf. But i am still get the incorrect sensor. i also noticed the aftermarket sensor i got had the pins in different locations than stock one. But sometimes lose boost like its losing vacuum. So next thing im going to do is get my intake pipe welded with some nipples so that its not just rubber hose sitting in the metal intake pipe. Then i got to get all the intercooler piping redone also. But i need to move the bov to the other side of the piping. Currently now i have it on the turbo pipe because thats just because i ran out of piping to adjust everything. But i need to put it on the throttle body side when i get the piping. One more thing to add sometime while driving now the idle will almost get stuck it seems like instead of going down to around 700 where i have it set. It will sit at like 2000 or 2500 until i give it gas. I was maybe wondering if it was the throttle plate getting stuck or maybe the cables. Like maybe i could try adjusting the cables on the throttle. Any other thoughts? And i dont know if i have said it but thanks for all the help it has been very helpful.

Re: In need of help with vacuum lines with front mount inter

Posted: Mon Sep 03, 2018 11:33 pm
by Legacy777
The incorrect MAF code could be a result of the wiring not being there or MAF just not having those pins. This diagram shows the pins. Basically pins 3 & 5 of the MAF are for the incorrect MAF sensor check.

https://main.experiencetherave.com/suba ... sting1.jpg
https://main.experiencetherave.com/suba ... sting2.jpg

Regarding the idle, do NOT adjust the cables, set stop screw on the throttle or anything else. The idle is electronically controlled and calibrated for the throttle plate/body from the factory.

I would suspect maybe a vacuum leak after the MAF which may be causing the high idle. Without some more info it's a little hard to say for sure.

Re: In need of help with vacuum lines with front mount inter

Posted: Fri Sep 21, 2018 12:13 am
by Chewysout2play
Might anyone know which ground is the ground for the maf? Is it one of the bolts that are on either shock tower?

Re: In need of help with vacuum lines with front mount inter

Posted: Sat Sep 22, 2018 8:42 pm
by mike-tracy
The ground for the MAF runs through the ecu plugs. Here's a useful document on the ecu pinouts:
viewtopic.php?f=19&t=53822

Ultimately I think the MAF gets grounded to that main ground on the driver side intake manifold.

Re: In need of help with vacuum lines with front mount inter

Posted: Tue Sep 25, 2018 1:13 pm
by Chewysout2play
So for an update on the car. I have fixed and corrected the intercooler piping so its will fit with the hood on the car. I have trimmed the intake pipe so I can fit my maf sensor on it now and be able to close the hood. Also found out why the car felt like it was misfiring a little bit. The brand new coil pack I put on. One of the pins was coming out so it was or wasnt making contact. But now the car drives pretty good. But the cel is still on and it's not flashing for the incorrect airflow sensor code this time. It's only flashing for the iacv code. Which I thought I fixed before but I'm not sure now I guess. I replaced the iacv eth a n/a control vavle and just added a 90 degree rubber hose to make it fit so it wouldn't hit the turbo. Any other suggestions there isnt alot in the manual

Re: In need of help with vacuum lines with front mount inter

Posted: Tue Sep 25, 2018 5:45 pm
by Legacy777
The CEL is on because the resistance values of the electromagnet portion of the IAC valve are not within spec. These ECU's are pretty dumb in terms of diagnostic so either the electrical part of the valve is bad/out of spec or the wiring to/from the ECU & valve is not good. The factory manual lists the testing procedure to check the valve and the resistances it should be. If that checks out good you need to check the resistance of the wiring going from the ECU to the valve. Also check the voltage going to the valve. This diagram walks you through the troubleshooting steps.

https://main.experiencetherave.com/suba ... C_Diag.zip