Single turbo fd no boost
 

Today was about 46°f , I took my fd and would not boost pass 3 psi and would back fire. It would go through gears and reach 70mph , but no boost. I have power fc. Injector duty 26- 35% when it would backfire. I have new profec electronic boost controller. Dual waste gate dump to admosfere (I can't hear them).
Yesterday the car worked great and boost great.
I have the UIM off the car to replace some vacuum line that I wanted to change. Next I will check the lines going to the waste gates.
I looked around some threads and one ended up being a cloth blocking the IC pope.
That's not my case. Any ideas to point me in the right direction to trouble shoot, would be helpfull..
Thank you

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Though I haven't acquired a large amount of experience with single turbo rotaries, I do have a decent amount of experience with turbocharged cars in general.

As I started to read your post, my first thought was an issue with the boost controller as you said it was new. But the fact that you're venting your wastegates (must be a sizeable turbo if you're running more than one!) to atmosphere tells me that it would be obvious if they were prematurely opening to shed the boost by malfunction of the controller.

Considering that, perhaps it's just a boost leak. I'd give it a boost leak test by pressuring the system. I'd also check for CEL's or anything odd thru whatever engine management you're using.

To eliminate the controller from being the issue, I would set it to "zero" so that the wastegates are doing all of the boost controlling. See if you still have the same issue.

perhaps your pfc fuel cut got changed.

perhaps your value under the primary to secondary fuel ramp kick in that time it takes to make that change got changed to a high value.


were you scrolling through the PFC at some point?

I didn't mess with the pfc or boost controller. The boost controller was working fine yesterday. I checked the lines from the waste gate and one broke off when I pulled a little bit. I will keep messing with it tomorrow and replace those waste gates lines.

Did this happen all day or just when it was cold?

My car tune was set up when it was at a warmer temp so it would really kick up a fuss if the temp of the engine was not up to snuff.
Once that temp was reached then the engine would boost fine.

It happened the whole day. I know what you are talking about, but this is different. It reach about 3 psi max at about 3k rpm, if I try to go wot it would go puff puff and not accelerate/fall on its face wont go into more boost. At that point I back off and not try to give more gass. If I accelerate slowly and reach 3 psi and shift I can hear the bov. I change all the vacuum lines, I will test it as soon as I am able. :crying:

couldn't be the boost controller, a boost controller cannot affect the turbo boost below the minimum that the wastegate can function at and i doubt that is at 3psi.

more likely one of your injectors is acting up, or your injector wiring is failing, or you have a plug wire arcing, or you have a fouled spark plug, or you have low fuel pressure, or you have a faulty coil, or, or, or...

Fuel presure is at 40, waste gate are set 8 psi spring each. it could be ignition system. I replaced the plugs 4 days ago, but the car ran fine. Spark plug wires are next to be change.

I had read that the pfC can go into limp mode/safe mode. If so, how can I access that option? I have to finish with the wire plugs first.
Thank you...

Oops.. pfc limb mode was for wrx guys. I guess it's different.

I have a dual wastegate set up and I am having a similar problem. Full boost 15 in 1st and 2nd gear. Third and above it sounds as though one wastegate gets stuck in the open position and I get 15 lbs but lowers quickly to 10

I have to test a bunch of stuff for what I can see. It's frustrating.. and I search and other similar issues are easy fix. The others didn't post any fix.
:scratch:

if you're not far i could take a look at it

I am about 3 hours from you I think. I wish i was closer. I found two striped wires right at the plug from the twin power to the coil harnes. I will keep looking. And testing.

make sure the map sensor line hasn't popped off, that any other vacuum lines or caps haven't been relocated and that all your turbo rubber couplers are intact and tight.

I replaced all my veccum lines with new ones aND new caps. My couplers are tight and good condition. I will start the car tomorrow and check.
Thanks..

Still have issues with no boost..:rant:
I took some snap shots of my power fc commander if helps..I am almost sure that the popping sound is coming from the waste gates dump. I guess I am going to check the waste gate see if they are stock open.

After hours of searching online, I found out that some one had the same issue and they found out that the waste gate spring were shot.. they had no resistance at all. Hopefully that's my case. I gave some spare springs. :fingersx:

I just removed the waste gates and they look good. I chenged the spring to 9 psi each though. Found no much carbon, it was fairly clean. So vaccum, boost leak and exhaust leak are out of the equation. The park plugs are good. Next to check wires, coils and fuel system..:scratch:

I guess I post my findings for folks with the similar issue like the one I was having. After checking vaccum lines, bov, wastegates, and ignition. I took out the fuel pump with less thank 7k miles and found a very dirty fuel pump strainer and changed fuel filter. My no bust issue it's gone.. my 7 is running like a champ. Thanks for all the guys that posted here.