car running strange after new vacuum lines

[TheFallen]

Before i start the thread, yes i have searched for my problems and im working on them, this post is so i can ask questions and get feed back and to also help with trying to figure out what is wrong. Thanks in advance for any help.

i have a 95 awd tsi, only mods are fmic and exhaust. my problem started two days ago, i re did all my vac lines, only thing i changed was the boost gauge (kid i bought it from had it t'd into the fpr vac hose) my bov is non recirc. (im working on that) i have checked and rechecked all the new vacuum lines to make sure they are connected and not leaking.

since the new vac lines i seem to be getting worse fuel mileage and i only seem to build 7lbs of boost, and at high rpms (5500+) it starts losing boost and will drop to 5lbs, it just seems slower and sluggish then what it was. Im working on a bl tester right now and will go test the system after i post this.

I have an exhaust smell in the car that seems worse as well (i only smell it while moving), it doesnt smell like normal exhaust but smells old, like when you start an old v8 up after it has sat for a few years. i have put all new gaskets on the exhaust and have plugged all the leaks and im still at a lost. i still have the egr but the previous owner cut out the evap canister.


i know its two different problems but i diddnt want to make two threads, and again thanks for any advice and help.


more info about the car, at idle it pulls 15-18in of vacuum and when slowing down in gear it will pull 24-25in of vacuum.

 

[1davho]

It could be that your wastegate is stuck open or partially open. And do a boost leak test.

Does your car still have a cat? It could be that your cat is plugged too.

 

[Breezio69]

When you say "replaced all the vac lines" did you literally get 1/2 a roll and pull them one at a time and replace? Where did you tee the boost gauge off of? Because that's actually an ok location to tee off of. However, the bov line and wastegate line are NOT the lines you want any tees.

One other thing, when I do boost/vac lines I always secure them with a medium zip tie, it helps fight boost leaks and secures the lines.... obviously right

So let us know where you teed off of, that could be your only problem.

Edit: also the exhaust smell could just be some leaky exhaust still, did you replace all of them including head to manifold? Did you pull the o2 housing and replace? Did you put the o2 sensor back in? Haha... or the o2 could just be bad?

 

[Cdc1221]

I'm just wondering if he plugged the fpr vac line back in. That could cause it to go rich and do exactly like he describes...

 

[1davho]

And as for lower boost, he could have bypassed the boost control solenoid and has it ran straight to the wastegate actuator. I would check a vacuum diagram to make sure everything is hooked up correctly.

 

[TheFallen]

well it does seem my waste gate is stuck open a little. so ill just get a new one. yes i did replace every line one by one and i didnt use zip ties, tho that is a really good idea. i do not have a cat, and the only gaskets i didnt replace on the exhaust are the manifold and turbo to manifold gasket, and yes i put the o2 sensor back in. every vacuum line has its own source, i moved the boost gauge over to a un used vacuum nipple. so fpr, bov and boost gauge have their own vacuum. and they are still hooked up.

1davho, you posted on my post yesterday i think, and yes i did leave the turbo lines alone. at the moment they are bypassing the bcs, there is the vac line going from the turbo to the wastegate. ill hooked them back up to the bcs.

thanks for all the help, ill order a new waste gate actuator and see if that will fix everything.

so after looking for wg actuators, (the dealer cant order one) on ebay there are a few that say t28/t25 some say nissian and others say universal. would this work or is there another place i can order one from?
i replaced the o2 senor about a month ago, but it could be bad. i'll get another one and see if that helps along with the waste gate.

 

[Breezio69]

If you don't mind another question.... what vac source did you tap into? The passenger side has one source, the drivers side has one source.

If you went off the throttle body or have a vac delete, you can only run off the port labeled p... I should have clarified that, that's why I ask where the gauge went. The other two need to be capped.

 

[TheFallen]

the boost gauge is tapped on top of the tb along with the egr, the fpr is going to what i guess is the stock port on the driver side of the intake, the turbo vac lines are now stock, going into the bcs and intake.

on another note, i did find another wg actuator that was on another t25 i had and put it on. (it does open and close) and im still having the same issue. still seems sluggish and i start losing boost at 5500 or higher rpms. a friend mentioned i could run the wg vac hose into a vac source on the intake and see if that clears up my problem. i havent done this yet, but could that be a good test?

 

[1davho]

If the wastegate is closed for sure, than that eliminates that, but make sure that the new actuator isn't holding it open at all. And do a boost leak test before anything else. If you have leaks, it causes a lot of problems.

Oh, and you will be running less boost than stock if you run straight to your wastegate bypassing the boost control solenoid. Hook it back up and see if it fixes your sluggish problem

 

[Breezio69]

At this point I'd be inclined to call a boost leak, sounds exactly like mine. I'd spike 9psi and end up at 6-7 around the same rpm as you... should have been pushing 15. Does the turbo just sound like its spooling out of control when you only hit 7psi?

Mine (with the boost leak) sounded louder at 6-7psi than it does normally at 15... if that makes sense? Like its overworking to only supply half your boost

 

[TheFallen]

I redid all the vac lines from the turbo to the bcs. No it doesnt sound like the turbo is working hard. I have a good pull up to 5500rpms then feels sluggish and I lose boost. I couldnt find any leaks when I did a bl test but I do have a rubber hose going from the turbo to the fmic. Maybe those are leaking.

 

[1davho]

When you do a boost leak test make an adapter to hook on to the intake side of your turbo. That should pressurise the whole system. Pressure it up to about 15 psi and listen for leaks. I also found that if you take cigarette smoke and blow it into a vacuum line and then pressure the system it makes it a little easier to find small leaks.

Also try changing your fuel filter. That is always a common problem with loss of power.

 

[TheFallen]

I will try the smoke and see what I can find and I'll get a new fuel filter. Who knows how long its been since it was changed.

 

[Nasty Dream]

I will try the smoke and see what I can find and I'll get a new fuel filter. Who knows how long its been since it was changed.

just don't smoke while you change the fuel filter, please.

 

[TheFallen]

just don't smoke while you change the fuel filter, please.

Ha ha oh I wont. But on a good/bad note all the rubber intercooling hoses leak a little. So looks like I get to redo all of those. I want to thank all of y'all for your input, advice and help. Hopefully this is the last issue I have for a while. Owned this 6 months and its been nothing but problems since I bought it.

 

[grudgedoutgsxr]

Recirc yo BOV bro, i had the same problem venting to the atmosphere dude. Less sound the better, oh yeah check your fmic couplers.

 

[Nasty Dream]

I paid a little more for the Turbonetics intercooler couplers. Maybe it's overkill, but I've had it for 10 years with no issues. I used silicone, but I see they have nitrile now. I don't know anything about them, they could be used for liquids, maybe.

http://turbocharged.com/main.htm