Pulling fuel in last trim, possible boost leak.

Hi all,

 

Looking for some help through my current issue. I am working with Dave at Cryo, he has been awesome so far but obviously is a little ways away and therefore can't fix the some of the mechanical stuff that is coming up with the tune.

 

Dave thinks I have a possible boost leak. If you take a look at the attached LV my final fuel trim is at -6, and has been between that and -8.

 

I have pressure tested with a home made kit and my intake will hold 5psi and only lose at 0.1 psi per second. I did see a little oil residue on the underside of the stock TMIC where they normally fail on the turbo coupling, so I bought a BP'd stocker from xtea that should be here on weds.

 

If this doesn't solve my issue, any ideas where I should look next? I didn't have my stock injectors cleaned when I had the engine out, would a leaky injector cause my trim to look that way.

 

Running a breakin map at the minute limited to 10psi. No apparent vaccum leaks, TGV and block gaskets are new, as is the bov oring, blue t has been zip tied.

 

I did see a little bubbling from the plastic sensor on the block next to the turbo. Can't remember what the sensor is for, but I assume that's just crank case pressure from charging the vac system while the engine isn't running.

Lv

Also, I am seeing a little low load knock and a pretty good stumble around 2-3k. Around 10 misfires in the last 1000 miles, mainly at idle and across all cyls but mostly on #4

That last one, the "final" I think is for high speed? Which probably means when the system is under more boost? I said this before, I would check the bpv.

 

I would buy a used aftermarket or new oem. If it doesn't solve the issue then resell or return. You probably won't lose any money on it.

I usually blow in them with my mouth as compressed air can be loud, thus hard to hear a small leak. Maybe a smoke test where are you located? Sounds like probably the TB hose, intercooler, or BOV to me.

I usually blow in them with my mouth as compressed air can be loud, thus hard to hear a small leak. Maybe a smoke test where are you located? Sounds like probably the TB hose, intercooler, or BOV to me.

 

Thanks Mike, I actually read through your pre tune info on here straight after my rebuild, tried the small bov hose blowing technique and couldn't find anything - system seems to hold great pressure when its low.

 

If this new TMIC doesn't work then its a smoke test/new BOV as my next steps, i'm located in western Maine.

Have you checked the conditions of the end of your TB hose? If it is still OEM, they tend to fail especially with increased boost pressure.

Have you checked the conditions of the end of your TB hose? If it is still OEM, they tend to fail especially with increased boost pressure.

 

Tmic side, yes, looks ok. I haven't looked at the manifold side as it's never been removed, maybe I should check that also.

Yeah, I am talking the TB hose between the manifold and tmic. That's the one that have a tendency to separate, like it did on mine. So do check that hose.

Any solutions yet?

Any solutions yet?

 

Car's been sitting, using the work truck - USPS have delayed the package, should be in today!

Could just be rich, if its hitting boost okay and not pulling timing...

Ok, trusted bp'd TMIC installed, still seeing the same fuel trims.

 

I saw a pretty good knock event also today, luckily I was doing a cruise log - does the ECU cut boost every time it gets a knock? Either I am losing huge amounts of pressure at once causing the knock, or its the ECU reaction. I have included a snippet of the log where the event occured.

 

My next thought would be the BOV, all the other boost connections seem good.

 

I'm almost at the end of the road for my level of expertise.

 

https://www.dropbox.com/s/63pmc7arlfrx6py/knockevent.xlsx?dl=0

Yeah, I am talking the TB hose between the manifold and tmic. That's the one that have a tendency to separate, like it did on mine. So do check that hose.

 

 

Did you check the TB hose especially on the manifold end? I don't see you mentioned that.

Did you check the TB hose especially on the manifold end? I don't see you mentioned that.

 

I did, no tears but it was actually a little loose when I installed the new TMIC, all buttoned up tight.

There is a bov for sale in the forums!

There is a bov for sale in the forums!

 

I see there is also a $25 stocker there too. I think at this point it would be smart to have someone give me second opinion - the car is going to Alberto at Motive some time next week. Ill probably have him do my diff/trans fluids while we are at it.

I woukd not get a used stocker. You wont know if it leaked or not. The one i replaced was used.