Opps.

The process for verifying if the MAF is working correctly is outlined in the service manual.

I have never heard of a cut MAF wire making it so the car doesnt hit peak boost, but I guess its a possibility.

Do you have the full stock exhaust system on? Just asking, because when I had my brand new IX, completely stock, I was only hitting about 16-19psi for peak boost. I didnt hit target boost, until I installed a TBE.

Last, are you testing in 3rd or 4th gear? Boost will be lower then target in 1st n 2nd.

 

You lost me when you wrote that you had installed, "...the factory vacuum line..". What is a factory vacuum line?

Mitsubishi part number MN 143555, is a complete vacuum/boost hose assembly consisting of three hose sections joining together and emanating from a plastic "T" fitting. The factory assembly comes complete with precut hoses containing boost restrictor orifices. Even the hose clamps come included. This costs about 17 Bucks at the dealership.

Is the part that I have just described, identical to the part that you installed along with a factory BCS, when you eliminated the MBC?

 

Lots of folks state that the VIII's and IX's were setup from the factory at 18-19 PSI. Well I have an VIII and it came from the factory set at 14.5 PSI. So, I don't know. You can't believe everything....

I don't think it likely that your problem is due to a cut MAF sensor wire. But, I have been wrong an awful lot in life. It's easy enough to check the integrity of the MAF wiring at the weatherpak connector at the MAF adapter visually isn't it? Also, it would seem fairly easy to check electrical continuity with a tester wouldn't it? Granted, I know next to nothing about electricity.

So, it is my best guess that given proper boost/vacuum hose connectivity and routing that your problem is a lack of waste gate spring pressure. I don't want to bore everyone with my reasoning. But, I am willing to bet that your problem is causally related to the above.

At least you have to try out my theory because it is a possible and even a likely cause which has not yet been eliminated as potentially being linked to the unfortunate low boost issue that you are experiencing.

 

Full 3" TBE with a HFC and a megan o2 housing. On the intake side its a K&N filter on the stock MAS and stock intake pipe, stock intercooler and pipes, Evo 9 BOV.

Yes, the factory BCS line setup. 3 lines, 2 pills, 1 tee, all stock including clamps. It came off my friends EVO 9. I am assuming the EVO 8 and EVO 9 BCS lines/pills are the same, right?

 

I m not sure if the same. I think so though. I see no reason as to why they shouldn't be interchangeable.

 

If you yank the vacuum/boost hose assembly off for a minute leaving the BCS connected electrically. Plug off all open hose ends with golf T's etc. Then run a short length of 4mm hose from the compressor outlet tube's discharge nipple to the nipple on the WGA. Take the car for a WOT run and tell us if you still see the same 14-15 PSI peak reading when the car is set up this way.

 

I checked the MAF wires visually and they appear intact. I haven't checked for continuity yet. I popped the actuator arm off tonight and the wastegate itself moves freely. Also I was planning on tightening the wastegate arm tonight but it was already tight. I had to stretch the actuator's arm a little to get it back on the wastegate as it was.

It is important to note that I have only owned this car for a few months. I have no idea what exactly was done prior to me owning it except to say that most of what I have seen of the previous owner work is pretty shabby.

 

My thoughts exactly.

So run wastegate pressure. I will do that as soon as I have a chance, hopefully this weekend.

 

Yeah, exactly run what you call WG pressure. Then if it turns out to be low(which is what I suspect), then we'll increase by preloading it up to about 16-18 PSI. Once that is set, then we'll reconnect the BCS and the vacuum/boost hose assembly back to stock and see how she responds thusly "goosed." Try it out this weekend with a chilled half dozen aluminum cans.

 

Thanks for the help! I will report back. Now by preloading do you mean adjusting the wastegate actuator arm or is there another way? As I mentioned the WA arm is pretty tight, you have to pull it pretty hard to get it on the wastegate flapper.

Also I think I forgot to mention but all of my pulls are in 3rd gear.

 

this is what morons do

 

Yes, I agree wholeheartedly. Whenever someone decides to revive an old, long dormant thread such as this one we risk running afoul of the sound proverbial injunction which in essence states that it is best to let sleeping dogs lie.J

 

It's OK, 3rd or 4th are good for a stock spooling turbo.

 

I tend to use the word "preload" too loosely as an all inclusive term in these threads. But, yes I meant adjusting the spring tension by rotating the turnbuckle on the threaded end of the actuator rod.

 

Tight is a relative term in these cases. Tight for you is not tight for me, I assure you. At any rate it is best to take one's time in these cases and always start the journey from ground zero.

The first step is to adjust the length of the actuator rod to the point where the hole in the turnbuckle freely slides on and off the peg on the WG's pivot arm while gently pulling the pivot arm back toward the WGA canister with the tip of your left index finger. That is... the axial center of the turnbuckle hole should line up directly onto the axial center of the peg on the pivot arm and slide freely on and off while taking the slack out of the pivot arm motion by gently pulling it back toward the WGA canister with a free finger.

I need to know the boost reading when the WGA is set up in this way. This will be the starting point. "Base spring pressure."

There are some preliminary steps that you must take first in order to do this though. I'll try to post them up a little later today as duty is pulling me out the door.