Fuel Tank

Next question?  My truck sat for a lot of years prior to being put back on the road.  I have ordered a new PMGR starter that got here yesterday. Hope to get it on tomorrow,  the one that is on it seems to drag, and has a hard time with hot starts.  Truck starts and runs down the road fine, but when you stop and let it idle, it will go into a rough idle then die.  Then it is usually pretty touch and go on getting it restarted.  I have changed fuel filter several times and have added another inline filter.  When it rough idles and dies, the exhaust smells like paint thinner (old gas).  I have filled it up several times always and am still getting this smell.  I have ordered a new front tank and will be installing it when it gets here.  Question is, should I replace in tank pump, or put an external electric pump on?

Thanks,
Carl

The 460 fuel systems are complex.  I think I'd replace the in-tank pump rather than modifying the system.

On the idle, it sounds like you are flooding, or at least getting really rich at idle.  How long has it been since the carb was rebuilt.  If either the power valve or accelerator pump is leaking you'll have way too much gas at idle.  And the exhaust will stink.

It is a brand new Holley,  I was going to rebuild the motor craft Holley  that was on it, but decided on a new one after getting it off.  I have adjusted the idle circuits using a Vacumn gauge.  Thanks Gary,  I will order a new in tank pump and fuel level sending unit to go in the new tank.

Carl

Cbarnes wrote

It is a brand new Holley,  I was going to rebuild the motor craft Holley  that was on it, but decided on a new one after getting it off.  I have adjusted the idle circuits using a Vacumn gauge.  Thanks Gary,  I will order a new in tank pump and fuel level sending unit to go in the new tank.

Carl

Being its a Holley have you checked the fuel level in the bowls?
Some of the new Holley's have see through sight plugs others you have to pull the screws out.
Have something to put out a fire if one should start before doing any work on the carb.

When the checking I like to set the level just below the opening and when I shack the truck the fuel will just start to come out. That is the first thing that is needed when adjusting Holley's.

Is the choke closing when cold and opening all the way when up to temp?
Then when up to temp you can then adjust the idle speed & mix screws.

If it still stalls when you let off the throttle we can dig deeper, what is the motor pulling for vacuum at idle in gear? Power valve should be half that as a start and adjust from there.
Dave ----

Thanks Dave,

This carb has the new sight glasses, and both are just barely visible when running.
To be honest, I didn’t check the vacumn with the truck in gear.  I did let it warm up, and adjusted the idle mix to get the highest vacumn.  

I have the new front tank and in-tank pump ordered.  The smell that I get after it rough idles and then dies smells like turpentine, or old gas….it doesn’t smell like it is flooded or running rich.

Cbarnes wrote

Thanks Dave,

This carb has the new sight glasses, and both are just barely visible when running.
To be honest, I didn’t check the vacumn with the truck in gear.  I did let it warm up, and adjusted the idle mix to get the highest vacumn.  

I have the new front tank and in-tank pump ordered.  The smell that I get after it rough idles and then dies smells like turpentine, or old gas….it doesn’t smell like it is flooded or running rich.

If the gas is old then any adjustments are almost for nothing as old gas dose not burn good as you are finding out.
Also if 1 tank has good gas and the other bad make sure the switching valve is working right.
It could be stuck pulling from the bad gas tank.
Dave ----