Hi Guys,

I have an LNF 08 with catless downpipe, ottp charge pipes, and short ram intake. Trifecta select-a-tune. 23psi.

I posted a few weeks ago with a boost problem with my car. I went WOT from second gear and it hit around 4500-5000RPM and just died. Then, it would boost either 0kpa-20kpa. A little later, maybe i could get to 40kpa, but thats max. This is with or without the tune. There is no irregular sounds.

The only light my car gives is an underboost. I have replaced the MAP sensor (no change), spark plugs (no change), did a fuel pressure test (fine), did a boost leak test (tight, no air escaping). We also checked the waste gate and it seems to be working right.

At this point my mechanic suggests replacing sensors but as you know sensors cannot be taken back so ill be burning through my wallet.

Any help?

 

Boost leak check again? Did you do it in the right place?

 

Yes we did it where the upper pipe goes into the turbo

 

Check your bpv on the turbo, a boost leak test will not test the sealing quality of it.

 

Bump

 

sounds like the same issue im having. im not getting any CEL though. itll boost completely fine, then just randomly not go past 0?

sometimes it does it, sometimes it doesn't. it's 100% intermittent.

i wonder if it's the tune. we are both on trifecta.

 

also, if it won't boost, and i turn the car off then on, it'll be fine. have you tried that yet.

 

my car was wonky before the tune so i dont think its that. Are you high mileage?

 

Ya sometimes mine does that too. But then sometimes i pull from second and it dies at high rpm

 

Bump cmon

 

My
Mechanic gave up. He cant find the problem. Bump. Help.

 

that sucks. my car has a cel and it indicates low boost code and maf sensor.

 

I had a boost problem as well, i just left the battery unhooked overnight (hard reset on the computer) and my boost returned. however my CEL (P0100) is still present. worth a shot! quick and easy hope it helps

 

Op did you check the bpv?

Boost leak test yours.

 

Where is it located! And how can i check it?!

 

Right beside the turbo. 3 bolts. Not really sure how to test that portion besides a take apart and visual.

 

I've had the same issues and seems like mine is fixed (minus still have valve gunk). Here's some ideas of stuff to check.

-injector seals, they can come off. The white seals on early lnfs go bad (they are now black and e85 safe).
-I had a small leak around my maf because the rubber grommet behind the maf was twisted and not pushed back for a good seal. This fixed my maf code in addition to...
-Rocker arms and lash adjustors. I had a rocker arm come off and never realized it until my tuner did a pull. Pretty common I've read, if you pull the valve cover you can check if one has broke or just came off. I had a rocker arm come off, this plus my maf rubber grommet being off fixed my maf codes.
-valve gunk. My car hesitates and acts weird for first 5 miles or so, then acts better. Still have random misfire codes and they seem to go with coked valves. Goes away when I stop driving like a grandma. Going to try seafoam, but only real fix is walnut blasting valves or a new head. Lots of threads on this issue.

Hope that helps

 

Thats the first is visually check it for rips/tears and make sure the vac line is connected

 

Check your intercooler. My car has the same code and it's because the intercooler is cracked. To fix at a dealership they will charge you from $900-$1000 depending where you go.