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Old 02-25-2004, 11:54 PM   #1
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Default NO boost!! Help!!!

Well, Will wasn't the only one having fun with boost today. I was too, and brought it up so high I think I broke my boost guage -seriously. I went out to take some pics of the needle sitting in the 12 psi range (still have the stock 3.8" pulley), and just after I took the last pic there was a loud pop -not sure where it came from. Right after that the boost guage dropped to zero where it stopped. I let off the gas and it didn't drop into vacuum either.
I shut the car off and restarted it and the guage did the sweeping thing with the other guages that they do when just powering up. But as soon as they settled the boost guage needle returned right to 0.
I popped the hood open and checked all the lines going into all the sensor around the supercharger and they are all in place.
It went to zero immediately after the loud 'POP' sound that I heard. I have shut the car off and restarted it few times and it is still stuck.
The supercharger is still boosting -very obvious that it is boost fairly high going by the way the car pulls harder now. Feels like there is even more boost. I took it out for one more prolonged run in boost (with no boost guage) and I have never seen the speedo climb that fast. Just going by my own timer in my head I went from 60-115mph in what I estimated to be about 8-9 seconds. Pulling like MF the whole way. I stopped and did a full throttle take-off with the TC off and in Perf Shift -another in-my-head-timer run, this time 0-60 in what seemed about 6 seconds, and I was trying not to count fast. Funny thing was the timing didn't feel like it was being pulled back nearly as much as other times I have done that.

Back on topic, what might have happened? Bad guage, blown vacuum line (checked all connections AT the supercharger end, but didn't get to the other ends.
The pop seemed to come from the center of the dash, but down low, almost in the floor-board. It was quite powerful -powerful enough to even feel it.
Doesn't sound like there'* any exhaust or intake leaks that might have been the result of the pop, and the engine runs smooth too.
No SES light either.
P.*. I will post pics of the 12-psi pics as soon as cardomain gets up and running again. Unless someone wants to host my pics.
Sorry for making this so long. Any help would be greatly appreciated.
Thanks in advance,
Martin
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Old 02-26-2004, 12:15 AM   #2
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Maybe you popped the manifold pressure sensor?
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Old 02-26-2004, 12:38 AM   #3
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Quote:
Originally Posted by fuddyduddy121
Maybe you popped the manifold pressure sensor?
Is that in the rear manifold? If so that is probably what it was. The noise came from about that spot.
Is that sensor one that can be reinstalled or will I need a new one?
Thanks again,
Martin
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Old 02-26-2004, 12:39 AM   #4
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I can't think of anything other than that. If you blew your wastegate, and it WASN'T dumping boost, but letting it stay on all the time, it still wouldn't explain the funky readings.
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Old 02-26-2004, 12:49 AM   #5
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Why are you getting so much boost on the stock pulley? Thats twice the boost you should get with that pulley!

Shawn
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Old 02-26-2004, 12:58 AM   #6
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Quote:
Originally Posted by dbtk2
Why are you getting so much boost on the stock pulley? Thats twice the boost you should get with that pulley!

Shawn
I haven't any clue why I'm getting that much boost. I've only got the CAI, Taylor Spiro Pro'*, NGK TR55'*, and removed the MAF screen for mods. Now I'm weery of putting the 3.4" on like I was planning to do at the MNCGP meet/mod day on Saturday. I'll just have to have on of the GP guys run their Autotap on the car to get some real-time readings of what'* going on under my hood.

As for the MAP sensor, is it located just above the rear valve cover, but under the wiring harness? If so I just went and looked at it (best I could with a very nippy wind kicking my butt). I felt around it for hoses and connections and what I could see and feel all looked to be in place (need to try again when my fingers aren't icicles).
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Old 02-26-2004, 01:03 AM   #7
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These are the best two pics I got (I can't hold a camera very steady when the car is pulling that hard).

You can kinda see it'* up around 12 psi in this pic.



About 11 psi here.

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Old 02-26-2004, 02:01 PM   #8
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I don't have a newer manual, so I'm not sure if the MAP sensor and the boost sensor are the same. I don't know why they wouldn't be.
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Old 02-26-2004, 02:48 PM   #9
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I'm at a loss for location on your car, as well, but I'm betting that sensor was the reason your boost readings were off to begin with. You should be getting no more than 7-8psi with that setup.
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Old 02-26-2004, 03:14 PM   #10
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I gotta agree with will, that'* the only thing that makes sense.
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