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Loss of boost after plug wires change?

Bluemagic

Bluemagic

New member
Ok I changed my spark plug wires this Morn and I was going to tidy up my vacuum wires so I removed the vacuum lines by the front valve cover and the one to the right of it. Got short on time and hooked them back up because I had to go. Ok now I have three bars of boost. Confused? Usually it fills right up. Now I'm getting three bars.
 


did you uplug the BBV sensor? Sounds like it's either unpluged or the vacuum line was not put back on it.
 
Ok I'll check everything out in a few.
Is it ok to drive if I can't find the issue? As long as I stay off the boost?
 
i installed a boost gauge and it seems a little slower would that be because there is more vacuum line? just curious
 
gtpeddie said:
i installed a boost gauge and it seems a little slower would that be because there is more vacuum line? just curious
Click to expand...

The blower displaces 90 cubic inches per revolution. The volume of the the vacuum line is less than 1 cubic inch. At idle, 1000 rpm(easy math), the blower is moving 90,000 cubic inches per minute. Yes more volume but you would never be able to tell the slight difference.
 


Ok checked hoses on bbv. Everything looked fine. Any other suggestions? Ive never had this problem. Should I remove all the hoses and reconnect them?
 
As someone already stated you might have a tiny crack in one of the hoses.....that you moved.....just a guess check the tee under the super charger snout.......that is a big culprit.......also if you have a vacuum gauge handy hook it up and see the vacuum at idle and when you rev it.......it should be high at idle and then go down really fast when you rev it and then hold steady.....
 
Sorry I didn't read your whole post originally... You're likely not seeing any difference in boost pressure, but you may have cracked or broken vacuum line going to the Map sensor. You also may have disconnected the line going to the MAP sensor. This is what the PCM references for boost that you see on your gauge.

The map sensor is located in the back of the engine bay near the fuel rail and above the valve cover.
 


91f98ff6.jpg


The culprit! Thanks guys. Now the elbow is broken under the map sensor lol. Oh how I love thee lol
 
Back to this, ok finally found the leak. Vacuum is 19.5 at idle. It used to be 15.2. Great? Right? No.

Now the bbv is stopping boost. Took lines off and instantly got full boost Lol. How can I resolve this? Do I need a new BBV?
 
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