Hello everyone this is my first post here so I apologize if this isn't the correct section!
I have owned a 64 1/2 Mustang I6 170 for about a year now and have still yet to have it on the road. When first got the car it ran but wouldn't idle low (Below 1000 rpm). It had the wrong distributor, wrong carburetor and a few other issues that I thought would cause the problem. I replaced the carburetor with the correct automatic Autolite 1100 and the distributor with the correct vacuum advance distributor. I set the timing, adjusted the valves (hydraulic in this case) and put new fuel in it. So I took care of the obvious and was still having a problem! From there I started the real diagnosis process. I ran a compression test and all the cylinders had good compression. From there I put a vacuum gauge to the intake, the vacuum was rapidly going from 15-20 back and forth. So I thought there it is I have a sticking valve! I took the head off and took it to my local machine shop and had them go through it and put new valve seals and re-seat the valves. I replaced the head gasket and exhaust gasket then put the head back on. I then readjusted the valves and put it all back together. It would not run unless I was constantly giving it gas. From there I readjusted the carburetor checked the valves over again and got it running without my foot on the pedal while still at a high rpm just like before. I put the vacuum gauge on and I am still having the same problem! If anyone has any experiences with a problem similar to this I would love the advice I just want to get my car on the road and to be able to enjoy it! This is my first vintage project and this is all pretty new to me so I am sure I have missed things that would be obvious to someone familiar with these vehicles.
TL;DR Vacuum gauge going from 15-20 rapidly and it doesn't appear to be a sticking valve.
I have owned a 64 1/2 Mustang I6 170 for about a year now and have still yet to have it on the road. When first got the car it ran but wouldn't idle low (Below 1000 rpm). It had the wrong distributor, wrong carburetor and a few other issues that I thought would cause the problem. I replaced the carburetor with the correct automatic Autolite 1100 and the distributor with the correct vacuum advance distributor. I set the timing, adjusted the valves (hydraulic in this case) and put new fuel in it. So I took care of the obvious and was still having a problem! From there I started the real diagnosis process. I ran a compression test and all the cylinders had good compression. From there I put a vacuum gauge to the intake, the vacuum was rapidly going from 15-20 back and forth. So I thought there it is I have a sticking valve! I took the head off and took it to my local machine shop and had them go through it and put new valve seals and re-seat the valves. I replaced the head gasket and exhaust gasket then put the head back on. I then readjusted the valves and put it all back together. It would not run unless I was constantly giving it gas. From there I readjusted the carburetor checked the valves over again and got it running without my foot on the pedal while still at a high rpm just like before. I put the vacuum gauge on and I am still having the same problem! If anyone has any experiences with a problem similar to this I would love the advice I just want to get my car on the road and to be able to enjoy it! This is my first vintage project and this is all pretty new to me so I am sure I have missed things that would be obvious to someone familiar with these vehicles.
TL;DR Vacuum gauge going from 15-20 rapidly and it doesn't appear to be a sticking valve.