Vacuum Advance Problem
06-26-2010, 08:23 PM
#1
Thread Starter
Join Date: Jun 2010
Location: IN
Posts: 35
Vacuum Advance Problem
1963 Falcon, 6 cylinder, 170 cubic inch, 2.8 liter
Runs smooth at idle and in gears when cold. Would go in and out of all gears, no problem. After driving 10 miles and getting warm it dies when put in gear, especially reverse. Once restarted it would run rough. Let it sit a half an hour to cool and it runs fine again.
Replaced:
Carburetor
Ignition Coil
Rotor, Condenser, Distributor Cap
Plugs
Wires
Just discovered that it has essentially NO vacuum at the port in the carburetor going to the distributor. What would cause the a lack of vacuum at the carb? How do I fix it? Would this have to do with the problem noted above?
Any help much appreciated.
Runs smooth at idle and in gears when cold. Would go in and out of all gears, no problem. After driving 10 miles and getting warm it dies when put in gear, especially reverse. Once restarted it would run rough. Let it sit a half an hour to cool and it runs fine again.
Replaced:
Carburetor
Ignition Coil
Rotor, Condenser, Distributor Cap
Plugs
Wires
Just discovered that it has essentially NO vacuum at the port in the carburetor going to the distributor. What would cause the a lack of vacuum at the carb? How do I fix it? Would this have to do with the problem noted above?
Any help much appreciated.
06-27-2010, 06:33 AM
#2
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
a carb usually has two different pickups. manifold vacuum and ported vacuum. ported vacuum is above the throttle plate, so therefore there is no vacuum at idle. sounds perfectly normal to me. the problem must be somewhere different.
maybe ignition timing, vacuum leak
since the problem only occurs when warm, it might be that the carb is running too rich, however it can be a problem with a gasket as well that the car only gets to see when warm. check all vacuum hoses at engine and to transmission if there is one
do you have powerbrakes, and if you do do you have the same problem when stepping on the brakes at idle?
maybe ignition timing, vacuum leak
since the problem only occurs when warm, it might be that the carb is running too rich, however it can be a problem with a gasket as well that the car only gets to see when warm. check all vacuum hoses at engine and to transmission if there is one
do you have powerbrakes, and if you do do you have the same problem when stepping on the brakes at idle?
06-27-2010, 08:50 AM
#3
Thread Starter
Join Date: Jun 2010
Location: IN
Posts: 35
No power brakes.
I've thought putting a new gasket under the carb. I've had it off several times and have used the same gasket. I've sprayed carb cleaner all around the bottom of the carb with no effect, so I thought it was sealed tight with no leaks.
I've thought putting a new gasket under the carb. I've had it off several times and have used the same gasket. I've sprayed carb cleaner all around the bottom of the carb with no effect, so I thought it was sealed tight with no leaks.
06-27-2010, 11:31 AM
#4
6th Gear Member
Join Date: May 2009
Location: PA
Posts: 5,232
Power brakes use manifold vacuum, an entirely different matter.
The carb gasket wouldn't have anything to do with vacuum advance, either.
06-27-2010, 02:17 PM
#5
3rd Gear Member
Join Date: Jul 2005
Location: Sugar Land, Texas
Posts: 566
If you have an automatic choke, the spring may be damaged or the unit needs to be adjusted. This may cause your engine to run normally until warm then cause a change in idle if the choke is not working properly...just my 2 centavos...
06-28-2010, 07:33 AM
#7
Thread Starter
Join Date: Jun 2010
Location: IN
Posts: 35
Timing was set at 11 without the vacuum line plugged in. When the vacuum line was plugged in it was at 12. Chilton's says 12 for automatic transmission. Loosened the bolt holding the cleat that holds the distributor in place. Couldn't turn the distributor for the life of me. Was afraid of what kind of problems I could get myself into if I forced it with a pry bar or something. So I decided to leave well enough alone.
Still at a loss.
Still at a loss.
06-28-2010, 03:38 PM
#9
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
a) a stuck distributor is quite common with the stock model. some haven't been turned for 40 years. the way to get them out is always the same: loosen the bolt that holts it down and then get them to turn first. if the distributor doesn't turn you will break it when you try to pry it out. simply, turning is more important than lifting for this. once it turns it will lift as well. you see i'm adement with this, a lot of people broke it before trying to pop it out. what gets them to turn is penetration spray, sometimes heat, sometimes brute force.
b) you can buy an infrared thermometer and measure with that. best place to measure i find is right under where the thermostat sits, but check other places as well to be sure. they're cheaper than you'd think and worth every single penny
spitting out gas could well be trouble with ignition timing. 12 should be good enough in idle to not cause any ill effects. but you should check for vacuum leaks as well:
get some WD40 and spray it around the imtake, at the carburetor base. basically everywhere but directly into the carb. when the idle changes while you do that then there's a vacuum leak exactly where you're spraying. as said spray at intake gasket, carburetor and carburetor base at least
b) you can buy an infrared thermometer and measure with that. best place to measure i find is right under where the thermostat sits, but check other places as well to be sure. they're cheaper than you'd think and worth every single penny
spitting out gas could well be trouble with ignition timing. 12 should be good enough in idle to not cause any ill effects. but you should check for vacuum leaks as well:
get some WD40 and spray it around the imtake, at the carburetor base. basically everywhere but directly into the carb. when the idle changes while you do that then there's a vacuum leak exactly where you're spraying. as said spray at intake gasket, carburetor and carburetor base at least