I pulled the plastic engine cover of my 97 series 2 gtp and was looking over the vaccum lines for cracks and stuff.I had the MOTOR vaccum line routing and componant location book, the service expert version and I have a line that is not listed in it for any sc engine. It runs from the same connection as the power booster and the sc valve on the left side of the sc(actuator maybe?). It runs over to the firewall and then to the right side of the car. It then goes behind the fuse and relay box where it goes from hardplastic to a rubber hose and disappears. Any idea what it is and use?
Also my boost gauge does not seem to work, is it vaccum or run off a computer sensor. Not a big deal as I'm putting in autometer gauges anyway just curious.
Thanks John

Here's a vacuum routing diagram for a GTP. The line may be the accessory vacuum line for the HVAC system. It routes in a similar fashion off the SC and then over to the battery and fuse box and then into a big harness going into the firewall. Are you having any problems with the vents or HVAC control?

http://i5.photobucket.com/albums/y186/lizzywiz/vacuum.jpg

Boost in a stock configuration is derived from the PCM. The Autometer boost gauges are better and will run off engine vacuum off the MAP sensor. Also, if you have a smaller SC pulley than stock it is common for the stock boost indicator to act weird.

Ok I do not have an automatic climate if that is what you mean. Just basic heat ac and fan controls. All of my vents seem to work. I have not run the ac yet. Heat blower and defrost do work. The line does come off like the acc. one on the diagram. Runs from there to the firewall across to the rt fender well and then down under the washer res. and the power dist. box to a connector to change to a soft rubber hose and disappears.

The gauge reads nothing at all even at full throttle to seventy mph. It is still the factory pulley.

Ok I do not have an automatic climate if that is what you mean. Just basic heat ac and fan controls. All of my vents seem to work. I have not run the ac yet. Heat blower and defrost do work. The line does come off like the acc. one on the diagram. Runs from there to the firewall across to the rt fender well and then down under the washer res. and the power dist. box to a connector to change to a soft rubber hose and disappears.

The gauge reads nothing at all even at full throttle to seventy mph. It is still the factory pulley.

Both manual HVAC and auto digital climate control use vacuum for controls. The line has to be the accessory vacuum feed. On both of my L67 GTP and Regal GS the line is connected and routed the same.

Your boost gauge itself may have a problem.

Ok thanx I figured the gauge was busted. And thanx for the info on the hose. It bugged the heck out of me not knowing.

ON a bone stock 2002 with the 3100,I have a vaccum line from the top of the engine towards the battery then down and into the firewall,It broke,would this also be for the vents in the a/c, heat? New blower motor but little air flow.

ON a bone stock 2002 with the 3100,I have a vaccum line from the top of the engine towards the battery then down and into the firewall,It broke,would this also be for the vents in the a/c, heat? New blower motor but little air flow.

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