bureau_c

Hey everyone,

I am having a problem, discussed previously, where I am getting little or no boost most of the time in 1st and 2nd gear. I have more success in 3rd gear, but for now, I just want to make sure I have in mind all the things that can possibly cause almost no boost on the primary (max of 1 or 2 psi).

- Boost leak, usually between primary compressor and intercooler but could really be anywhere

- Bad primary turbo

- Collapsed intake hose (would the car drive OK other than the low boost in this situation, or would it choke it too much even for that?)

- Wastegate or precontrol stuck open (would this flow enough to limit boost that low?)

- Charge relief or air bypass acting up (can these things vent enough boost to account for it being that low?)

Comments on any of these possibilities will be appreciated, as well as any other suggestions.

jds

adam c

iTrader: (2)

I would suspect a vacuum hose has popped off, or is leaking. Check all around the little black pressure tank, in front of the UIM. Remove the tank, and check underneath it too.

If your primary turbo works some of the time, that means that the turbo is functioning. The problem is actuating it. It does not sound like a boost leak.

Fatman0203

Possible your actuator could be stuck. After about weeks of trouble shooting my 2nd turbo I went non sequantial. When I removed the actuator it was siezed.

areXseven

iTrader: (1)

Your CCV on the y-pipe may not be closing, thus, allowing all the primary boost to flow into the secondary turbo. Check the vacuum lines in that area.

BoOsTin FD

Could we also discuss 2ndary turbo problems. I started couple of threads some time ago, but never really solved my problem.

My turbos are rebuilded, ported wastegate, No vacuum leaks, Changed TCA, CRV, bov, CCA is fine, Most of the solenoids changed, Vacuum chamber, Vacuum hoses, IC couplers and bunch of other crap.

I got Dp, midpipe, catback, intake, profec b, PFS ecu, and some other stuff. I get 12-10-12,11,10.5 Now it starts droping from 12 to 11,10.5 after 5500rpm or so.

It has been doing that since I have owned this FD. At one point i thought i fixed it, but was only fooling myself. Thought maybe 2nd turbo was bad, it did blow oil and was smoking, so i rebuilded it. Still got the same problem.

I kind of gave up on trying to figure this out, but it still bugs me a lot. I remember before i rebuilded them and when i went Non-seq it did the same damn thing.

So i just want to know if anyone might know something that I may have overlooked and that it could be the problem.

Amel

bureau_c

Hey hey hey, I gotta get my primary working before I can worry about the secondary.

My main purpose in asking about the various reasons for no primary boost, I wasn't so sure the various different paths the pressurized air can take have the ability to vent off enough boost to make it 1 or 2 psi. It sounds like you all think that they can. I know a boost leak will do it, but I'm pretty sure I don't have that (no wooshing sound for one). I'm pretty sure I don't have a hose popped off or a bad solenoid because we just did the whole sequential hose job/check solenoids ordeal trying to fix this. My theory on the bad turbo (even though they were just rebuilt so they shouldn't be bad) is that if they're partially seized and hard to turn, maybe there's not enough oomph to the exhaust to effectively turn the turbine until 3rd gear. It may be a bogus theory, I don't know.

jds

Jack

iTrader: (2)

If you are getting very little boost in primary then full boost when secondary turbo comes on line, check the pre- spool rod. There is a C clip that had fallen off mine
creating the symtoms above.

areXseven

iTrader: (1)

F*&cked up.

areXseven

iTrader: (1)

iginally posted by bureau_c [/i]
..... My theory on the bad turbo (even though they were just rebuilt so they shouldn't be bad) is that if they're partially seized and hard to turn, maybe there's not enough oomph to the exhaust to effectively turn the turbine until 3rd gear. It may be a bogus theory, I don't know. jds [/QUOTE]

The way to check to "see" if the primary turbo is spooling is to take off the Crossover-Tube. At cold start-up, like in the morning, you should get gail force winds coming out of the y-pipe.

Another way to check is to remove the intake pipe and intake inlet elbow off the primary turbo. You'll be able to see the compressor wheel spool as you rev-up the engine. If it doesn't spool, then you've got major issues.

bureau_c

I'm not getting any boost to speak of from any of the turbos in 1st or 2nd gear.

jds

bureau_c

I would imagine there will be no gale force winds...at the crossover point if I'm getting pressure there I'd be getting boost wouldn't I? At that point there's nowhere to go but into the intercooler and then the motor. I don't have the car at the moment, its still at the shop that put in the turbos. I'm not sure if they've done the 2nd test you mention, but they need to...they probably don't want to think about the turbos maybe being bad!

jds

The way to check to "see" if the primary turbo is spooling is to take off the Crossover-Tube. At cold start-up, like in the morning, you should get gail force winds coming out of the y-pipe.

Another way to check is to remove the intake pipe and intake inlet elbow off the primary turbo. You'll be able to see the compressor wheel spool as you rev-up the engine. If it doesn't spool, then you've got major issues. [/B][/QUOTE]