vacuum lines

terribleonexx88 · March 13th, 2007, 06:51 PM

these two lines coming off this are vacuum where do they hook up to? would these snipped vac lines cause hesitation?

soocutlass · March 13th, 2007, 07:38 PM

these are not necassry to hook up. How it is used is when the temp of the motor goes up it allows for your vacuum advance to work, if the motor is not up to temp the ignition timing vacuum advance will not work. So it act as a vacuum switch based on temperature to open.

soocutlass · March 13th, 2007, 07:41 PM

originally it look like to switch that is mounted in the intake not the air breather sorry.

terribleonexx88 · March 13th, 2007, 08:53 PM

well the two rubber lines are snipped off and i can feel the vacuum so they were hooked up to something and i cant find what. im trying to figure out why my car hesitates from a stop and i notice those lines 2day and was wondering if that had any thing to do with it

Oldsguy · March 14th, 2007, 05:57 AM

If you have a vacumm leak because those lines are snipped off and not plugged that could cause your hesitation. I would plug the one from the vacumm source and find out where the other one goes and remove it. It seems that only one should have vacumm on it. Seems like what soocutlass said is right except it works on inlet air temperature instead of engine temperature. I suppose the best thing to do if your car is still completely stock is to replace the hoses onto the device and let it be. Your car is an '88 Cutlass right? There was lots of computer interaction with the engine timing by that time and unless you remove the whole thing and re-tune your engine to run without it you might be better off just to leave it all on.

terribleonexx88 · March 14th, 2007, 01:58 PM

its a 78 cutlass

soocutlass · March 14th, 2007, 03:59 PM

I would cap off both side of the sensor because if it is a temp switch which it looks like then it will open after it reach temp and the idle problem will come back.

Jim's rare 80 · March 15th, 2007, 03:26 AM

Hi. I have an 80 Cutlass. The good is.. it's in pieces, being restored, and will be like new soon. The bad is.. It's in pieces, being restored, and I can't drive it right now. The other good is, I know this is a thermal switch to control the secondary choke pull off. It's fed off of your breather vacumn supply. If this is leaking air, it will cause hesitation, if you have a 4bbl carb, don't bypass it. Let us know engine and carb config', and we'll go from there. Jim

terribleonexx88 · March 16th, 2007, 01:00 PM

its a 2bbl. does any one have pictures of there 260 2bbl i can look at because the vacuum diagram i looked at didnt help me. i took off the thermal thing altogether and it still hesitates. to get going i have to tap the gas and let off repetedly.

March 14th, 2007, 05:57 AM	#5 (permalink)
Oldsguy Hot Rodder at heart Administrator Join Date: May 2004 Location: Lees Summit MO Posts: 5,360	If you have a vacumm leak because those lines are snipped off and not plugged that could cause your hesitation. I would plug the one from the vacumm source and find out where the other one goes and remove it. It seems that only one should have vacumm on it. Seems like what soocutlass said is right except it works on inlet air temperature instead of engine temperature. I suppose the best thing to do if your car is still completely stock is to replace the hoses onto the device and let it be. Your car is an '88 Cutlass right? There was lots of computer interaction with the engine timing by that time and unless you remove the whole thing and re-tune your engine to run without it you might be better off just to leave it all on. __________________ Dan '77 Cutlass Supreme '46 2 door "The rocket 455.....it's a sledgehammer approach to a thumbtack world" LuxBlue of HAMB.

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March 13th, 2007, 07:38 PM	#2 (permalink)
soocutlass Junior Member Join Date: Mar 2007 Posts: 15	these are not necassry to hook up. How it is used is when the temp of the motor goes up it allows for your vacuum advance to work, if the motor is not up to temp the ignition timing vacuum advance will not work. So it act as a vacuum switch based on temperature to open.

March 13th, 2007, 07:41 PM	#3 (permalink)
soocutlass Junior Member Join Date: Mar 2007 Posts: 15	originally it look like to switch that is mounted in the intake not the air breather sorry.

March 13th, 2007, 08:53 PM	#4 (permalink)
terribleonexx88 Junior Member Join Date: Mar 2007 Posts: 15	well the two rubber lines are snipped off and i can feel the vacuum so they were hooked up to something and i cant find what. im trying to figure out why my car hesitates from a stop and i notice those lines 2day and was wondering if that had any thing to do with it

March 14th, 2007, 01:58 PM	#6 (permalink)
terribleonexx88 Junior Member Join Date: Mar 2007 Posts: 15	its a 78 cutlass

March 14th, 2007, 03:59 PM	#7 (permalink)
soocutlass Junior Member Join Date: Mar 2007 Posts: 15	I would cap off both side of the sensor because if it is a temp switch which it looks like then it will open after it reach temp and the idle problem will come back.

March 16th, 2007, 01:00 PM	#9 (permalink)
terribleonexx88 Junior Member Join Date: Mar 2007 Posts: 15	its a 2bbl. does any one have pictures of there 260 2bbl i can look at because the vacuum diagram i looked at didnt help me. i took off the thermal thing altogether and it still hesitates. to get going i have to tap the gas and let off repetedly.