232 dies after warm-up

So my Dad's 1972 Gremlin dies as soon as it's warm. It starts perfect and runs great up until this point. It was just purchased for him by my brother as a gift. It was sitting in storage with a full tank of gas for about 22 years. We siphoned all of the old gas out and had the carb rebuilt but still have these problems. The shop that rebuilt the carb says we need a new gas tank because it is sucking up all the grime and rust on the bottom of the tank. What I don't understand is why it starts and runs perfect for about 10 minutes then dies? It ran and drove great the first day we picked it up! I agree it needs the tank pulled and cleaned out but I am not sure that's the problem with it dying. Anybody have any ideas?

I am with Pacerman on the carb. Other thing to check is the intake/exh manifold bolts to the head if they are lose. When on fast idle the choke is on too and it runs richer. When choke pulls off it is now not richer and if the bolts are lose will have a vacuum leak. Also check all vacuum hoses for cracking causing vacuum leaks. You can use carb cleaner with the straw so you can point where it will spray. With motor running as slow as it can go, may need to turn up the idle speed to keep it running, spray along the head where the manifolds bolt. If the idle speed changes you have a vacuum leak and if tightening the bolts does not fix it then a gasket replacement is in order.

 

For the tank if you don’t have some place local try http://gastankrenu.com/  I used them to do a Javelin tank that was also leaking.

Dave ----

I did two tanks with Eastwood's tank kits. One had pinholes all over the bottom. Not a drip in 8 years.

RickyRodder wrote: Thanks guys! We will definately be pulling the tank and cleaning it out. I was unaware the fuel was fed through a different port during cold start. Good to know!

It is not a different  port or circuit during “cold start”. It has to do with RPM anything a little above idle the carb uses a different circuit.

I know Holley’s have 3 circuits Idle, midrange rpm & high range rpm and each has it’s own adjustments. I am not up on other carbs but thinking cant be much different just might not have the adjustments as the Holley?

Dave ----

Yes. The carburetor was adjusted. They had us go in and siphon all the old gas out and put a few gallons of new gas in so they could do it. They drove it around the day before giving it back to my Dad but when we picked it up it died as soon as we pulled out of the parking lot. The shop told us we would have problems until we change out the tank because of how dirty it is. I just couldn't understand why it would run so good at startup but die when warm.