Technical 1962 Olds 88 394 Fuel Pump Dilemma

1962 Oldsmobile Dynamic 88

394 4 barrel Rochester carb


Hello, I am new to this forum. I purchased a 1962 Olds 88 last fall (2025) and this past spring my mechanical fuel pump began spraying fuel from the bowl. I tried replacing the gasket (with cork and a gas resistant rubber), the bowl, and the filter but every time fuel shoots out where the bowl meets the fuel pump.


I bought a replacement fuel pump but the arm was too short and didn't touch the camshaft. I bought another fuel pump but the pump action was upside down. These were both supposed to fit a 62 olds 394.


I then installed a low pressure (4-5psi) electric pump and blocked off where the mechanical pump sat on the engine. However, I believe the engine is experiencing vapor lock. The original mechanical fuel pump had a return line connection to the fuel tank, I just capped it.


I then had the carb rebuilt to ensure it was in good working order.


I then installed a fuel pressure regulator after the electric fuel pump to solve the vapor lock issue but fuel keeps dripping out where the fuel enters the fuel pressure regulator. The regulator showed a 4.5-5 psi which I understand seems to be a good pressure for the carb and engine.


Ideally, I would like to find a mechanical pump without a filter bowl (I added one before the carb) and a return line port to the fuel tank.


I am getting frustrated and trying to figure out which direction to move forward. Try another fuel pressure regulator? Has anyone dealt with this situation? any words of wisdom?

 

You shouldn't have vapor lock with an electric pump, but glad you got it fixed. Sounds like you just have a leaking regulator left to deal with. You'll need to investigate that junction.

Where is the electric pump? Back at the tank area where it should be or up front?

What was the cause of the vapor lock-non standard fuel lines running right by the exhaust? A mechanical pump gets alot of heat from the block, as well- that's the reason for the return line.

Is the regulator a dead-head design or return style? Using a return style up front and the return line plumbed with an electric pump in the back is the most reliable way to cure vapor lock, (unless the pump or alternator dies on the highway).

Maybe one of the Olds gurus here can sort you out with a mechanical pump source if that's your goal

-rick

 

Have you spoken with Fusick? 860) 623-1589

 

There are reputable companies that can overhaul/test your pump. Mine retains the gl*** bowl but it’s empty because I use an AC gl*** bowl filter before the carburetor. I used Egge in So Cal because I trusted their work for mechanical pumps. But there are others who use ethanol safe parts.
Since the Oldsmobile used a return line system I would use it.

 

Sounds like a very typical day in the life of an old car owner

 

Put a T in the fuel line at the engine and connect it to the return line. And get rid of the "pressure regulator"

 

@Paul , any suggestions for OP?

 

no

the leak at fuel bowl should be easy to diagnose and remedy, basic mechanical skill required.
the 4-5 psi electric pump shouldn't need a pressure regulator. as said already it should be mounted near the tank and will not contribute to vapor lock.
without pictures it's impossible to identify what wrong mechanical pump(s) he has.
leaking at connections also require basic mechanical skills.

the best way to learn this stuff is by doing

 

I replaced my fuel pump purchased on eBay (seller VPJIRI)with a rebuilt pump on my 324 Olds engine cuz the vacuum pump was weak.( too weak to operate wipers)
I was experiencing vapour lock and installed a 1/2” carb spacer on advice from other vintage Olds engine owners. Spacer prevented carb getting so stinking hot on that cast iron manifold. Was also advised to only run 91 octane,,nothing less. I dont get vapour lock anylonger.