Lost boost today

nickleman60

Registered User
:confused:.............. I took the black '94 out for a spin since it was a nice spring day, I was almost home and decided to have a few seconds of WOT. I hit it from a 20 mph roll and she took off for a couple of seconds then went flat, I didn't know what had happened so I gave it some throttle and she was a slug with the boost gauge staying on the vacuum side. My first thought was it either lost the sc or jackshaft belt, pulled in the driveway, opened the hood and the belts are still there. I then moved the throttle linkage for some rpm's and checked to make sure the bypass diapham was working and it was. There were no strange noises around the snout/sc that I could tell. That's as far as I got for today so I'm now thinking that it might be something in the snout, shaft maybe, causing the rotors not to turn. I'll remove the sc top probably tomorrow and see if the rotors are turning when I turn the shaft. Anyone have any other ideas of what might have happened?
 
If it fell on its face it your DIS, If you have a spare I would change it out.

Jerry
 
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Coupler in the snout ok? Pull the belt and spin it by hand and see if you feel the coupler/gears/rotors turning. How's the oil in the SC?
 
Coupler in the snout ok? Pull the belt and spin it by hand and see if you feel the coupler/gears/rotors turning. How's the oil in the SC?

It's a new MPX case with a rebuilt snout and new solid coupler, fluid in the sc was full when installed. I'll look at it tomorrow after work and see if I can locate the problem.


Damn these things are pigs with no boost...................:rolleyes:
 
check for proper operation of the bypass actuator... if you had catastrophic blower failure, you would know. i'd bet money on your bypass....
 
check for proper operation of the bypass actuator... if you had catastrophic blower failure, you would know. i'd bet money on your bypass....

I already did check the bypass, that and the belts were the first things I checked when I got home, hit the throttle and watched it close. I'm speculating that it's something in the snout, all outward appearances point to that area.
 
The butterfly may have come off on the bypass valve preventing it from actually closing. Rare but possible.

More likely the aluminum hub that presses onto the drive shaft in the snout came off. I've seen this happen, and when it does you lose all drive into the blower. No noise, no drama, just no internal blower rpm. It generally only ever happens when a snout has been rebuilt as the hub has to be pressed off and on, and being aluminum, it tends to deform and therefore not fit as tight the 2nd time around. Kind of like our HB's. :rolleyes:
 
More likely the aluminum hub that presses onto the drive shaft in the snout came off. I've seen this happen, and when it does you lose all drive into the blower. No noise, no drama, just no internal blower rpm. It generally only ever happens when a snout has been rebuilt as the hub has to be pressed off and on, and being aluminum, it tends to deform and therefore not fit as tight the 2nd time around. Kind of like our HB's. :rolleyes:

That's what I'm thinking it is, if so I have another snout that needs a seal then it'll be ready to bolt on.
 
Removed the sc belt and sc top and the shaft must be stripped. I held the rotors with one hand and spun the pulley with the other so I guess when I get the supercharger off and take off the snout I'll see the real problem. I ordered a seal for my spare snout so when that comes in I'll be ready to install it.
 
Removed the sc belt and sc top and the shaft must be stripped. I held the rotors with one hand and spun the pulley with the other so I guess when I get the supercharger off and take off the snout I'll see the real problem. I ordered a seal for my spare snout so when that comes in I'll be ready to install it.

Well, like I said the shaft isn't the problem, it's the aluminum hub that comes loose. You'll see when you get it apart. :)
 
Any update to this Keith? Or are you waiting to take it apart till you have a seal?

I'll start the removal today when I get home, I played golf yesterday afternoon and my old azz was too tired to mess with it when I got home...........:D
 
Tore down the sc today and found that the hub was stripped and slipping on the shaft.

As soon as a new snout seal gets here I'll install my other snout.
 

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So the piece with the pins in it is slipping on the shaft? Are they basically one-use or you just have to know what you're doing?
 
Dave says it best:

It generally only ever happens when a snout has been rebuilt as the hub has to be pressed off and on, and being aluminum, it tends to deform and therefore not fit as tight the 2nd time around. Kind of like our HB's.

Between a hardened steel shaft and an aluminum hub we all know which will fail first.........................:rolleyes:
 
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Changed the snout and got everything back together. Took it for a spin and all seems well.................:D

Now, if I could just get it to Dalkes garage for a tune...........................:rolleyes:
 
How badly was the hub slipping? Mine won't make any boost, and I've ruled out anything else I can think of. I can hold the rotors and twist the pulley, but it doesn't seem to slip by doing that.
 
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