Hesitation after warm engine

[SteveJ]

See if you can watch the video attached @Palmettobug

Upload Photo.mp4

[240260280z]

21 hours ago, Palmettobug said:

I just replaced the spark plugs yesterday. The first three appeared to be white. The second three appeared more blackish.

Your carbs' fuel metering is not balanced, The front carb is not giving enough fuel. I will assume needles are mounted correctly in the SU pistons and that the SU pistons are not binding and there are no intake leaks:

1. Check to make sure the jet nozzles move up and down freely and that the choke is not causing either to be up or down (for tuning I always disconnect the choke wires at the carbs and push the jets all the way up "just to make sure").

2. Adjust the jet level on the bottom of the front carb lower (to give more fuel) then drive for a bit then check the plug #2 and compare to the plug #4's colour.  Keep adjusting the front jet level until both are the same.

 

This should fix your plug colour.

 

From experience, your loss of power is either inadequate fuel delivery (debris in tank, weak fuel pump, low fuel bowl levels) or a failing/maladjusted points distributor or failing condenser).

[SteveJ]

Just a couple of notes from experience:

1. Buy a non-contact infrared thermometer. Take the temperature at the thermostat housing when you think the gauge is reading high. The stock thermostat should open at 160 degrees.

2. Make sure you don't have any loose bolts on your exhaust manifold. I had a couple work loose under the rear carburetor. One of the symptoms was crappy running when the car had been sitting in traffic because the exhaust leak was right under the rear carburetor and would heat up the intake on cylinders 5 & 6.

[Palmettobug]

My engine bay is not as great as your friend's, but I'm trying. I though the mechanical fuel pump was this little blue motor thing right behind the first carb. Whatever it is, it has two wires that have female connectors which aren't connected to anything. There is a small hose that comes out of it on the right side that is plugged.

 

I think think pictures shows the mechanical fuel pump.....

The small silver circular thing with the blue collar around it by sparkplug #1. Since that's where the fuel line runs... BTW, while pulling lightly on the sparkplug wires to make sure they were all seated correctly, I also pulled on the fuel hose that runs into that mechanical fuel pump. I don't think it's suppose to split off in your hand...... I had to run into town and get a new hose as it appears the fuel ate into the delivery hose. Problems possibly caused by air leaking into the fuel line???

I have since adjusted and synched the carbs (again). The air flow on both appear to be 9.5 back and front. Adjusting the mixture is a pain as I have big knobs on the bottom of the carbs instead of flat nuts like most directions refer to. My tach is adjusted to 900 at idle.

[SteveJ]

Yes, the mechanical fuel pump is on the right side of the engine toward the front. I guess a PO fabricated that blue box as an AC compressor bracket.

Rotten fuel line will let air into the system. It's good just to replace as much as you can.

Verify that the electric fuel pump is running/pumping, otherwise it's just drag.The voltage regulator would normally be right where the AC compressor is. Did someone swap to an internally regulated alternator?

[Palmettobug]

That was going to be a question of mine a little further down the line. How do I tell by looking if someone swapped the alternator?

Thought everything was synched right in the driveway. Tried to pick the kid up from school and the car died under accelerator load. Spent 30 minutes screwing with the carb adjusts to get enough power to make home. Stopped by Advanced Auto. Guy says he turned the front 1 and a 1/2 turns before it affected the rpm's, the rear one he turned 3/4 of a turn before affect on rpms. He said the front carb needs to go in for rebuild so you might as well do both.

Sound plausible?

And we haven't even gotten to suspension problems/questions yet. 

[SteveJ]

44 minutes ago, Palmettobug said:

That was going to be a question of mine a little further down the line. How do I tell by looking if someone swapped the alternator?

You look to see if the voltage regulator is missing.

If you haven't already, download the 72 & 73 factory service manuals from the link in my signature. The EE section will have info on the voltage regulator. The 72 will have good information on the carburetors.

You could also contact @Bruce Palmer from  Ztherapy  about the Just SUs video they sell.

[Palmettobug]

Yeah I think I'm going to have to call them for the video. Getting somewhat discouraged.

[SteveJ]

That's okay. You'll feel better after you get it running right.

[Patcon]

It's too early to get discouraged. One problem at a time. When you get it sorted you will be glad you stuck with it

[Palmettobug]

The manual doesn't say where the voltage regulator is located. I assumed it would be on the passenger's side , close to the alternator. But could you put one of those cool pictures up? I do much better with those.

[240260280z]