67 GTO Fuel Pump

Helping a neighbor who just took possession of a gorgeous Convertible Pontiac GTO. Started the first day he got it and he put about 30 miles on it that night. No issues at all. Next morning it won’t start. Engine turns over but not starting

I put a little fuel down the carb and it started right up and died.

moved backwards from the carb to the fuel filter and replaced it. Tried starting again and nothing

moved backwards again and now I’m at the fuel pump. I pull the line and tell him to crank it and nothing. I got no gas going to the carb. He ordered a fuel pump and we are doing it tomorrow. Am I missing anything? Just seems weird that it was running fine and the next day the carb is not getting any gas at all.

 

How old is the tank? Might want to swap that out too?

 

Check the electrical side of the pump? If it is electric.

Or is it the cam driven ones?

 

If it's stock the fuel pump is mechanical, if the fuel pump is rather old the rubber diaphragm inside the pump is probably dry rotted and has developed hole which will stop it from pumping gas, replace the pump and check again to see if the new pump is pumping gas, if so reconnect it and you should be good to go.

There's not much else that it could be with a mechanical fuel system, unless there's a blockage in the fuel line from the tank or in the tank, if the new pump doesn't fix it try blowing out the fuel lines, if still not working you are looking at something in the tank.

I cut my teeth working on this era and earlier vehicles, and now I'm still working on all era vehicles!

 

Tank is new.

 

I agree with your assessment. Everything points to the pump. In addition he literally just told me that he poured in a can of seafoam. I hate that shit. I’m wondering if the seafoam damaged the pump or blocked up a line. It was running fine when he took possession of it. I think that seafoam has damaged a line or diaphragm in the pump.

 

If its the original pump from back then I'm surprised he even made it 30 min.

That rubber must be gone gone.

 

If any of the fuel lines that are rubber and haven't ever been replaced in the last 5 to 10 years they could very well be soft and swollen and causing a blockage.

 

I went thru this last week on a ford expedition. Replaced fuel filter and then moved on to fuel pump. Inline sock filter was detached from old fuel pump when removed. Started right up and has ran fine since after new pump. Hated having the old sock in tank but not worth dropping tank to get it out.

Not a primary driven vehicle. Sits not used which is hard on vehicles.

 

I think it has sat for a long time too. Only 41k miles on it. I’m leaning towards that seafoam caused problems. Whether it freed up some rust, caused issues with the rubber lines. It literally ran fin 10 hours prior. The only change is the seafoam. My buddy builds race engines and when I told him he put seafoam in it, he literally said that’s the problem. He thinks the seafoam loosened up some rust, collapsed a line or damaged the pump. I don’t know why people add that. But hey. I appreciate you responding to me. Hope you have a great night.

 

Why did you post this in the 5th gen section?

It's probably the pump. The diaphragm tears and it no longer pumps. The same thing happened to my 67 and it's only like 2 bolts to replace it.