A chunk of the o-ring missing!? WTF! That means whoever installed that sensor did not have enough sense to lube the o-ring. I just purchased 2 of those o-ringed from crate engine depot because I'm installing my hot&cold side ic piping along with a zzp intercooler this weekend. I am a firm believer in NOT RE-USING GASKETS. It sounds like that may b the root of all ur boost/power loss problems.

Also I think the car needs a few key cycles or a certain amount of time running before it will throw a code after the you disconnect map sensor. I could be wrong but I'm sure if u leave it unplugged a CEL will appear and the car won't run correctly.

 

I HOPE the issue is the O Ring. I just ordered one through crate depot. Also....what do you lube it with?

Sorry for all of these questions....but I'm on my own here....I've only got you guys to help me out on this one. I've got so much money wrapped in the GMS1 and the Trifecta Tune....somehow...I HAVE to get this thing back to how it used to run!

 

No appology necessary man. That's what these forums are for! I would use a silicone based lubricant. After you have the oring on the map sensor, install it in a twisting motion.

 

Here is a picture of the damage O-Ring (Upper Map Sensor):



Is this enough for the car to run bad? (no constant boost)

 

FWIW. The instruction sheet with the GMTU kit says."Lubricate O-ring with clean engine oil before installation."

 

Ouch, SO I guess I was in the right direction with a VAC leak.

You should be able to replace the O-Ring from Auto Zone, or someone else.

 

okay, I guess my next step is to get the new O-Ring...not sure if that will solve anything.

I'm also going to go ahead and change the BOV spring too....I'm changing it (dejon) will not do anything...but I have to start doing something.


You think I should buy 2 new bosch map sensors too? I have no idea what else to do...

 

Bummer your still having issues....

If the O-ring doesn't fix, try these.... Again, just guessing here, somewhat educated but guessing just the same.

Have you tried un-doing the by-pass plate to look at it yet? could be broken spring or a rupture in your diaphram. you can also get under the car and see how easy it is to to push open the wastegate. its the rod to the right of the turbo, near the exhaust. it should move with a decent amount of pressure needed. if it moves easily, you are closer to finding your problem.

OR, AND THIS IS A BIG OR... Again overboost-cutback-boost...on stock parts with dual tunes. it will cost you forty bucks and 20 minutes to have them change out your DP. most of your problems will maybe go away. your 2nd tune is trying to pass more than you can get through 2.5" of pipe and 2 cats. The tune is set, I think from your earlier post, to your mods that havenot been put on yet....IE 3" cat-less exhaust.

 

I checked out the bypass plate, looks okay, I'm going to go ahead and replace the spring too...won't hurt anything to change it. Also....how do you "push open the wastegate"? I got under there...and tryed both ways to push it....it won't budge at all.

As for the DP....I just had it changed today....still isn't holding boost...does sound alot deeper and the turbo really hisses

I just do not get how it's never thrown a code for how bad it's running....as far as the boost goes. It used to kick a**....like a rocket!

 

And it will again.........soon,............really!! The 5lb boost thing really sucks, be careful don't pull out in front of any speedy grandmothers, in a 63 nova II. Have you changed the lower sensor ? they put a new one in mine, due to the rubbing. Would be nice to figure it out, must be rough, life without boost.