Vacuum line help
 

Alright, I have an 85 C10 with a 305 and an electric quadrajet. Engine turns on and off fine. The PO took semi decent care of the truck however, the carb has a lot of vacuum hoses disconnected or non existent. There are two vacuum lines connected on the carb, one on the front lower drivers side that runs to the canister and one on the rear lower centerline that runs up by the cruise control. As I fiddled around with the engine running I put my fingers over the tee coming off the front passenger side and the idle decreased notably. It also threw a check engine light probably related seeing how it wasn't there until I messed around. If anyone could give me some advice on which vacuum ports I should plug and which should be connected it would be greatly appreciated. Also, I removed all emission control stuff, the egr was plugged when I purchased the truck. When driving it sounds like I have a exhaust leak replaced both flange gaskets and snugged down the hand tight header bolts but didn't seem to help, don't know if that's related to anything, just thought I would throw it out there.

Re: Vacuum line help
 

Take a pic of your carb and engine bay. Easier for us to help. Your motor slowed down because you plugged off the vacuum leak.

Re: Vacuum line help
 

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Re: Vacuum line help
 

THat T is manifold vacuum source.
Plug them all if you're not using them. Should be able to buy a cap assortment at the parts store.
THe one under the fuel inlet run it to your vacuum advance pot on the distributor.
The screw in the hose. Pull the hose off at the tree end and cap it. The other hose on that T is cracked. Replace it.
What tranny you got?

Re: Vacuum line help
 

Vacuum advance on the distributor, that's bell shaped thing to the left of the distributor? Honestly I haven't had the chance to make my way to the transmission yet. It shifts smooth, so I figure I could wait before changing the filter and fluid. It's RPO code is MX0, if that means anything to you. Thanks for the help!

Re: Vacuum line help
 

Yup that's the dizzy vac pot. Helps your mileage with it hooked up.
I ask about tranny cause you need vac line to it if it's a turbo 350 or 400. Could be an O/D trans too.
Take another pic of drivers side of carb if you could.

Re: Vacuum line help
 

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the tranny does have overdrive, maybe tomorrow I will take the time to see if I can match up the tranny pan and figure out what I have

Re: Vacuum line help
 

I think I see a tv cable down there.
Here's a link to a chart to tell what you have.
http://montecarloforum.com/forum/eng...ary-not-21083/

Re: Vacuum line help
 

I appreciate all the help.

Re: Vacuum line help
 

My pleasure!! LOL!!!

Re: Vacuum line help
 

though maybe you can help me with another question. I know I ask for an inch and take a yard. The PO had a aftermarket tachometer wired in that I want to get rid of, no need for it really. I removed the negative cable from my battery to start tinkering with it and realized the way it's spliced in to the distributor it would just be easier for me to replace the distributor cap and rotor. had planned on doing this any way, so as I torqued down on the negative cable(it's a side post) the nut loosened up again like it's stripped. Anyway when I turned the motor over all my sensor gages where pegged either left or right, could this be caused by the loose negative cable?

Re: Vacuum line help
 

Not sure on that. You've found my weak point! LOL!!
THis nut you tightened. Was it a bolt instead with a small head. Stock one takes a 5/16" wrench.
I've seen them brake off inside the battery before.
Does the truck start and run?
Once again. Pics??

Re: Vacuum line help
 

Yup, that's the nut, no pictures this time daughter is asleep in the front room can't risk waking her up by slamming the hood, trying to stay on the wife's good side. I will have to look in the battery to see if it sheared off but I don't think it did. I can only figure the loose negative cable is causing a ground or for the first time the check engine light came on after messing around with the carb earlier and that's somehow messing with my gages. Hard to say my fuse box looks like a rats nest thanks to the PO.