Vacuum advance questions (complicated)

1985Mustang · 03-16-2001, 04:15 PM

When I installed my new intake, base timing at idle was 45 degrees. Needless to say it didn't run right, so I bypassed the vacuum advance sensor on the intake and ran the distributor hose directly to the timed port on the carb. Today I got this wild idea to run the distributor BACK to the sensor, and run the OTHER hose that is connected to the sensor to the timed port (it was previously on the full port). Now it runs great, and my question is was I supposed to have the sensor hose connected to the timed port originally, or does the new intake just flow so much more antifreeze that it was pulling too much vacuum at idle. Sorry so long and thanks.

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1985 Mustang GT

Edelbrock Performer intake, Edelbrock 600 carb, 9mm FMS wires, 15^ timing, no smog pump, 8.8 w/3.08

Bob · 03-16-2001, 07:16 PM

I just run the vaccum hose from the distributor vac. advance to the timed port on the carb. I think the sensor is in one of the 2 boxes of emissions parts that came out of my engine compartment.

Which intake did you put on?

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1985 Mustang GT

'85 GT 13.20 @ 105.8 / '72 Mach1
Long list...check website!!
My Website

RUSTANG · 03-20-2001, 12:39 PM

If I remember correctly (it's been a few years since I had that sensor) When the car is cold the dist pulls the vacuum straight form the main vacuum block on the back firewall through the sensor. When warm it pulls it from the port on the carb. That sensor is a delayed vacuum port for easier starts and warmups. I bypassed it altogether and ran a line straight from the carb port to the dist. I have gone to mechanical advance since then and use no vacuum ports. You may have had a hose on wrong or on the wrong port of the sensor. Sensor could be faulty too. Just ditch it.

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Currently rebuilding my 85 Mustang GT from the frame up. Check out my site for info on my car and specific information on the 85 Mustang.
http://www.FlemWorld.com

03-16-2001, 04:15 PM	#1
1985Mustang Registered Member Join Date: Oct 1998 Location: Knoxville Posts: 20	Vacuum advance questions (complicated) When I installed my new intake, base timing at idle was 45 degrees. Needless to say it didn't run right, so I bypassed the vacuum advance sensor on the intake and ran the distributor hose directly to the timed port on the carb. Today I got this wild idea to run the distributor BACK to the sensor, and run the OTHER hose that is connected to the sensor to the timed port (it was previously on the full port). Now it runs great, and my question is was I supposed to have the sensor hose connected to the timed port originally, or does the new intake just flow so much more antifreeze that it was pulling too much vacuum at idle. Sorry so long and thanks. ------------------ 1985 Mustang GT Edelbrock Performer intake, Edelbrock 600 carb, 9mm FMS wires, 15^ timing, no smog pump, 8.8 w/3.08

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03-16-2001, 07:16 PM	#2
Bob "Old School Gearhead" Join Date: Oct 1998 Location: Peru, Illinois Posts: 617	I just run the vaccum hose from the distributor vac. advance to the timed port on the carb. I think the sensor is in one of the 2 boxes of emissions parts that came out of my engine compartment. Which intake did you put on? ------------------ 1985 Mustang GT '85 GT 13.20 @ 105.8 / '72 Mach1 Long list...check website!! My Website

03-20-2001, 12:39 PM	#3
RUSTANG Registered Member Join Date: Jan 1999 Location: Dale City Va. Posts: 516	If I remember correctly (it's been a few years since I had that sensor) When the car is cold the dist pulls the vacuum straight form the main vacuum block on the back firewall through the sensor. When warm it pulls it from the port on the carb. That sensor is a delayed vacuum port for easier starts and warmups. I bypassed it altogether and ran a line straight from the carb port to the dist. I have gone to mechanical advance since then and use no vacuum ports. You may have had a hose on wrong or on the wrong port of the sensor. Sensor could be faulty too. Just ditch it. ------------------ Currently rebuilding my 85 Mustang GT from the frame up. Check out my site for info on my car and specific information on the 85 Mustang. http://www.FlemWorld.com