Here is the full situation. I installed Buschur's RACE FMIC and LICP on my stock turbo a few days ago. Ever since then I’ve been having a very strange problem. The only problem I had during either install was that i mistakenly used the two 12mm stock bolts where the turbo meets the LICP which i then replaced with the supplied 6mm alan bolts. The problem persisted through both sets of bolts. The problem did not occur before the install.

At half throttle and around 10psi (give or take 2psi depending gear) anywhere after 5000rpm the car bucks wildly. The boost gauge jumps up and down violently going as high as 16psi and dropping to as low 6psi extremely quickly. I brought it to a local shop and they checked all intercooler piping and made sure there were no leaks. Out of curiosity, and slight stupidity, I tried to see if the problem continued with the MAF unplugged and it worsened.

What could it be? I checked the plugs and they look fine. Could it be misfire? Wouldn't that throw a CEL?

I put in the stock bypass valve thinking maybe the HKS unit was leaking but it didn’t do much except smooth low end out a little.

Car has 13k miles and a fresh t-case from the dealer last week.

Mods:
Buschur 3" TBE
HKS 264/272
HKS SSQV vta
DNP 02 Housing
Fidanza Gears @ -2,-2
Injen Intake w/ UICP
Buschur Race FMIC*
Buschur LICP*
Dynoflash custom tune


*installed after initial tune

 

WOW. I would have guessed bad boost leak. Do a true pressure test. There is a DIY to make a pressure tester on here. Also (my choice), fighters garage sells one. I have theirs and it works great. Saved a buddy of mine as$ last weekend with a loose IC hose. After that, I would Vacuum test. Your BOV might not be getting the VAC it needs and it could be like wicked flutter in your BOV.

Good luck!

<edit by fourdoor>Don't try to get around the board prohibitions</edit>


Or fuel cut - but you have a flash...

 

OK let me ask this. The new Buschur Lower I/C pipe (deluxe) dose not have the nipple that the stock lower I/C pipe has. What did you do with the vacume hose that was connected to the nipple on the stock pipe.?

 

I changed out my lower IC pipe and I didn't have any nipple with a vac line on the pipe??? The stock air box to turbo has a vac and BOV opening. The vac goes from the Valve cover to the intake pipe? The only other connection on the intercooler pipes should be the BOV exit port (to the BOV by the battery).

 

no no, the buschur licp connects to the stock hard pipe(black) that has the nipple. haha its impossible to connect the buschur pipe alone without some major modification to the stock turbo.

 

I agree, that's the type of erratic behavior that occurs when hoses are connected improperly.
Can you look at another car or schematic to confirm proper routing?

It can pressure test fine as it may be a sealed system but inlets and outlets are incorrect.

If this is not the case, can you test AFRs?

 

I think we are on different pages here.

I ordered the the buschur deluxe FMIC it came with a new Lower Inter cooler pipe. The lower intercooler pipe from buschur connects right up to the turbo and replaces the stock black pipe that has a nipple on it.

I had my Supply side of my MBC hooked up to that nipple, and after I got the buschur deluxe FMIC with New Lower I/C pipe I had to hook my MBC differently.

 

the Bushur pipe DOES replace the stock black piece. The MBC was re-routed into the BOV line which is also what my boost gauge is running off of.

I have not done a full pressure test.....does anyone have the DIY link?

I don't have an AF gauge so unfortunately i cannot check.

Im stumped because how can it be a boost leak under such little boost yet at WOT (21 psi) the problem does not occur. Unless there is such a pressure change that the LICP is literally sucked upward due to the increase in pressure throught the piping eliminating the gap. Seems unreasonable

 

I am thing that you are calling the intake pipe between the airbox and the turbo the lower intercooler pipe... If not I am lost.

I attached a diagram of all the Intercooler Pipes in post #4. There are NO vacuum connections on ANY of the IC pipes. The lower IC pipe is "AIR PIPE A (part #11 on the charge air cooler). It connects to AIR HOSE A (#7 on the charge air cooler) which connects to the hot-side of the turbo and to AIR HOSE B (#12 on the charge air cooler) which connects to the Intercooler. It is a solid pipe.

I attached a diagram of the intake and I think you are talking about the AIR INTAKE HOSE (part #13 air cleaner). That is not the lower IC pipe. that is the only black hose/pipe in the whole intake system. The Vac port connects to a vac line (#12 air cleaner) that goes to the drivers side front of the valve cover and equalizes the pressure in the valve cover.

Hope this clears up any confusion.

 

I know what you're saying. I got the Deluxe FMIC and LICP and was confused as to why the LICP didn't have the nipple that the stock one has. I'm pretty sure I did the same connection as you. I used a "T" fitting to tap into the BOV line. Its been working fine for me.

 

really......mine fit without a problem.....hmmm

 

I'm with this guy, the LICP =outlet from the turbo to IC and has no nipples... or not understanding this either.

Induction pipe from turbo inlet to MAF has teh nipple

 

He's talking about this:

My MBC was hooked up to this nipple. The Buschur LICP doesn't come with one.

 

^ That is what I am talking about. However you stated that you re-routed the connection correctly, so it shouldent be the problem.

SO THERE IS A NIPPLE ON THE LOWER I/C PIPE!

The diagram in post #4, What year is that for? 2005 or the 2006? it dosent show the nipple.

 

Yeah, theres definately a nipple. And my Buschur LICP bolted right up to the turbo. I noticed some other people had to connect it to the black pipe with the nipple though. I don't know why mine would be different. Maybe its an updated version.